1.Transient Receptor Potential Canonical 4 and 5 Channel Antagonist ML204 Depolarized Pacemaker Potentials of Interstitial Cells of Cajal
Jun Hyung LEE ; Wen-Hao WU ; Xing-You HUANG ; Jae Yeoul JUN ; Seok CHOI
Journal of Neurogastroenterology and Motility 2020;26(4):521-528
		                        		
		                        			 Background/Aims:
		                        			To investigate an effect of ML204 (an inhibitor of transient receptor potential canonical 4 and 5 [TRPC4/5] channels) on interstitial cells of Cajal (ICCs) and therefore determine whether TRPC4/5 channels act on ICC-generated pacemaker activity. 
		                        		
		                        			Methods:
		                        			We enforced whole cell patch clamp analysis, measurements of the intracellular Ca2+ concentration, and reverse transcription polymerase chain reaction to determine the effect of ML204 (10 μM) or englerin A (a selective activator of TRPC4/5 channeles, 10 μM) and the existence of TRPC4/5 in mouse small intestinal ICC. 
		                        		
		                        			Results:
		                        			Treatment of ICCs with ML204 or englerin A caused the membrane potentials to depolarize. This depolarization effect of membrane potentials by ML204 in ICCs was observed to be concentration-dependent. After treating Ca 2+ - and Na + -free solutions or flufenamic acid (a non-selective cation channel blocker), the pacemaker potentials in the ICCs were abolished. A specific anoctamin 1 channel blocker did not have any effect on the pacemaker activity in ML204-untreated control cells; however, they blocked ML204-induced pacemaker activity in ICCs. Specific primers designed against TRPC4 and TRPC5 detected the presence of TRPC4/5 in small intestinal ICCs, and the application of ML204 increased raise the frequency of Ca2+ oscillations in ICCs, as assessed using Fluo-4 AM. 
		                        		
		                        			Conclusion
		                        			The results implied that ML204 could not inhibit the pacemaker activity but depolarized the membrane potential of ICCs by regulating intracellular Ca2+oscillations and anoctamin 1 channels. 
		                        		
		                        		
		                        		
		                        	
2.Neural-Induced Human Mesenchymal Stem Cells Promote Cochlear Cell Regeneration in Deaf Guinea Pigs.
Sujeong JANG ; Hyong Ho CHO ; Song Hee KIM ; Kyung Hwa LEE ; Jae Yeoul JUN ; Jong Seong PARK ; Han Seong JEONG ; Yong Beom CHO
Clinical and Experimental Otorhinolaryngology 2015;8(2):83-91
		                        		
		                        			
		                        			OBJECTIVES: In mammals, cochlear hair cell loss is irreversible and may result in a permanent sensorineural hearing loss. Secondary to this hair cell loss, a progressive loss of spiral ganglion neurons (SGNs) is presented. In this study, we have investigated the effects of neural-induced human mesenchymal stem cells (NI-hMSCs) from human bone marrow on sensory neuronal regeneration from neomycin treated deafened guinea pig cochleae. METHODS: HMSCs were isolated from the bone marrow which was obtained from the mastoid process during mastoidectomy for ear surgery. Following neural induction with basic fibroblast growth factor and forskolin, we studied the several neural marker and performed electrophysiological analysis. NI-hMSCs were transplanted into the neomycin treated deafened guinea pig cochlea. Engraftment of NI-hMSCs was evaluated immunohistologically at 8 weeks after transplantation. RESULTS: Following neural differentiation, hMSCs expressed high levels of neural markers, ionic channel markers, which are important in neural function, and tetrodotoxin-sensitive voltage-dependent sodium currents. After transplantation into the scala tympani of damaged cochlea, NI-hMSCs-injected animals exhibited a significant increase in the number of SGNs compared to Hanks balanced salt solution-injected animals. Transplanted NI-hMSCs were found within the perilymphatic space, the organ of Corti, along the cochlear nerve fibers, and in the spiral ganglion. Furthermore, the grafted NI-hMSCs migrated into the spiral ganglion where they expressed the neuron-specific marker, NeuN. CONCLUSION: The results show the potential of NI-hMSCs to give rise to replace the lost cochlear cells in hearing loss mammals.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Bone Marrow
		                        			;
		                        		
		                        			Cell Differentiation
		                        			;
		                        		
		                        			Cochlea
		                        			;
		                        		
		                        			Cochlear Nerve
		                        			;
		                        		
		                        			Colforsin
		                        			;
		                        		
		                        			Ear
		                        			;
		                        		
		                        			Fibroblast Growth Factor 2
		                        			;
		                        		
		                        			Guinea Pigs*
		                        			;
		                        		
		                        			Hair
		                        			;
		                        		
		                        			Hearing Loss
		                        			;
		                        		
		                        			Hearing Loss, Sensorineural
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Ion Channels
		                        			;
		                        		
		                        			Mammals
		                        			;
		                        		
		                        			Mastoid
		                        			;
		                        		
		                        			Mesenchymal Stromal Cells*
		                        			;
		                        		
		                        			Neomycin
		                        			;
		                        		
		                        			Neurons
		                        			;
		                        		
		                        			Organ of Corti
		                        			;
		                        		
		                        			Regeneration*
		                        			;
		                        		
		                        			Scala Tympani
		                        			;
		                        		
		                        			Sensory Receptor Cells
		                        			;
		                        		
		                        			Sodium
		                        			;
		                        		
		                        			Spiral Ganglion
		                        			;
		                        		
		                        			Transplantation
		                        			;
		                        		
		                        			Transplants
		                        			
		                        		
		                        	
3.Effects of oxidative stress on endothelial modulation of contractions in aorta from renal hypertensive rats.
Seok CHOI ; Hye Rang SHIN ; Sang Hoon KIM ; Mi Jung LEE ; Jae Yeoul JUN ; Hyun Lee KIM ; Jong Hoon CHUNG ; Cheol Ho YEUM
Kidney Research and Clinical Practice 2014;33(1):19-25
		                        		
		                        			
		                        			BACKGROUND: Endothelial dysfunction is linked to exaggerated production of superoxide anions. This study was conducted to examine the effects of oxidative stress on endothelial modulation of contractions in chronic two-kidney, one-clip (2K1C) renal hypertensive rats. METHODS: The 2K1C hypertension was induced by clipping the left renal artery; age-matched rats receiving sham treatment served as controls. Thoracic aortae were isolated and mounted in tissue baths for measurement of isometric tension. RESULTS: Norepinephrine-induced contraction was augmented by the removal of the endothelium, which was more pronounced in sham rats than in 2K1C rats. Nomega-nitro-L-arginine methyl ester, an inhibitor of nitric oxide production, had a similar augmenting effect. Vitamin C inhibited the contraction in aortic rings with intact endothelium from 2K1C rats but not from sham rats. The contraction was also suppressed by treatment with diphenyleneiodonium or apocynin, inhibitors of nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase, in the aortae with intact endothelium from 2K1C rats but not in those from sham rats. Superoxide anions generated by xanthine oxidase/hypoxanthine enhanced the contraction in the aortae with intact endothelium from sham rats, but had no effect in 2K1C rats. Enhanced contractile responses to norepinephrine by xanthine oxidase/hypoxanthine in sham rats were reversed by vitamin C. CONCLUSION: These results suggest that the effect on endothelial modulation of endothelium-derived nitric oxide is impaired in 2K1C hypertension. The impairment is, at least in part, related to increased production of superoxide anions by NADH/NADPH oxidase.
		                        		
		                        		
		                        		
		                        			Adenine
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Aorta*
		                        			;
		                        		
		                        			Aorta, Thoracic
		                        			;
		                        		
		                        			Ascorbic Acid
		                        			;
		                        		
		                        			Baths
		                        			;
		                        		
		                        			Endothelium
		                        			;
		                        		
		                        			Hypertension
		                        			;
		                        		
		                        			Hypertension, Renal
		                        			;
		                        		
		                        			Niacinamide
		                        			;
		                        		
		                        			Nitric Oxide
		                        			;
		                        		
		                        			Norepinephrine
		                        			;
		                        		
		                        			Oxidative Stress*
		                        			;
		                        		
		                        			Oxidoreductases
		                        			;
		                        		
		                        			Placebos
		                        			;
		                        		
		                        			Rats*
		                        			;
		                        		
		                        			Renal Artery
		                        			;
		                        		
		                        			Superoxides
		                        			;
		                        		
		                        			Xanthine
		                        			
		                        		
		                        	
4.Clinical study of benign and malignant fibrous-osseous lesions of the jaws.
Ju Min LEE ; Won Wook SONG ; Jae Yeoul LEE ; Dae Seok HWANG ; Yong Deok KIM ; Sang Hun SHIN ; In Kyo CHUNG ; Uk Kyu KIM
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2012;38(1):29-37
		                        		
		                        			
		                        			INTRODUCTION: Fibrous-osseous lesions of the jaws are difficult to diagnose precisely until excised biopsy results are found, so they might be confused with malignant lesions. This clinical study focused on the diagnostic aids of lesions that demonstrate different clinical, radiologic, and histological findings. MATERIALS AND METHODS: A total of 16 patients with benign fibrous-osseous lesions on the jaws (6 fibrous dysplasias, 6 ossifying fibromas, 3 cemental dysplasias, and one osteoblastoma) were reviewed. Nine patients with malignant fibrous-osseous lesions (8 osteosarcomas and one Ewing's sarcoma) were also retrospectively reviewed. RESULTS: Osteosarcoma patients complained of facial swelling and tooth mobility. The radiographic findings showed the irregular resorption of cortical bone and periosteal reactions. Histological features included cellular pleomorphism and atypical mitosis. An Ewing's sarcoma patient complained of tooth mobility and facial swelling. Onion-skin appearance and irregular expansile marginal bony radiolucency were seen in the radiography. Fibrous dysplasia patients complained of facial swelling and asymmetry. The radiographic features were mostly ground-glass radiopacity. Histological findings showed a bony trabeculae pattern surrounded by fibrous ground substances. Ossifying fibroma patients complained of buccal swelling and jaw pains, showing expanded cortical radiolucent lesions with a radiopaque margin. Histological findings were revealed as cellular fibrous stroma with immature woven bones. In cemental dysplasia, most of their lesions were found in a routine dental exam. Well-circumscribed radiopaque lesions were observed in the radiography, and cementum-like ossicles with fibrous stroma were seen in the microscopy. An osteoblastoma patient complained of jaw pain and facial swelling. Radiographic findings were mottled, dense radiopacity with osteolytic margin. Trabeculae of the osteoid with a vascular network and numerous osteoblasts with woven bone were predominantly found in the microscopy. CONCLUSION: Our study showed similar results as other studies. We suggest the clinical parameters of diagnosis and treatment for malignant and benign fibrous-osseous lesions of the jaws.
		                        		
		                        		
		                        		
		                        			Biopsy
		                        			;
		                        		
		                        			Fibroma, Ossifying
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Jaw
		                        			;
		                        		
		                        			Microscopy
		                        			;
		                        		
		                        			Mitosis
		                        			;
		                        		
		                        			Osteoblastoma
		                        			;
		                        		
		                        			Osteoblasts
		                        			;
		                        		
		                        			Osteosarcoma
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Sarcoma, Ewing
		                        			;
		                        		
		                        			Tooth Mobility
		                        			
		                        		
		                        	
5.Endothelium-dependent vasodilation by ferulic acid in aorta from chronic renal hypertensive rats.
Seok CHOI ; Hyun Il KIM ; Sang Hag PARK ; Mi Jung LEE ; Jae Yeoul JUN ; Hyun Lee KIM ; Jong Hoon CHUNG ; Cheol Ho YEUM
Kidney Research and Clinical Practice 2012;31(4):227-233
		                        		
		                        			
		                        			BACKGROUND: Ferulic acid (FA) is a naturally occurring nutritional compound. Although it has been shown to have antihypertensive effects, its effects on vascular function have not been intensively established. The aim of this study was to assess the vasoreactivity of FA in chronic two-kidney, one-clip (2K1C) renal hypertensive rats. METHODS: Hypertension was induced in 2K1C rats by clipping the left renal artery and age-matched rats that received a sham treatment served as a control. Thoracic aortas were mounted in tissue baths to measure isometric tension. The effects of FA on vasodilatory responses were evaluated based on contractile responses induced by phenylephrine in the aortic rings obtained from both 2K1C and sham rats. Basal nitric oxide (NO) bioavailability in the aorta was determined by the contractile response induced by NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). RESULTS: FA induced concentration-dependent relaxation responses which were greater in 2K1C hypertensive rats than in sham-clipped control rats. This relaxation induced by FA was partially blocked by the removal of endothelium or by pretreating with L-NAME. L-NAME-induced contractile responses were augmented by FA in 2K1C rats, while no significant differences were noted in sham rats. FA improved acetylcholine-induced endothelium-dependent vasodilation in 2K1C rats, but not in sham rats. The simultaneous addition of hydroxyhydroquinone significantly inhibited the increase in acetylcholine-induced vasodilation by FA. CONCLUSION: These results suggest that FA restores endothelial function by altering the bioavailability of NO in 2K1C hypertensive rats. The results explain, in part, the mechanism underlying the vascular effects of FA in chronic renal hypertension.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Aorta
		                        			;
		                        		
		                        			Aorta, Thoracic
		                        			;
		                        		
		                        			Baths
		                        			;
		                        		
		                        			Biological Availability
		                        			;
		                        		
		                        			Coumaric Acids
		                        			;
		                        		
		                        			Endothelium
		                        			;
		                        		
		                        			Hydroquinones
		                        			;
		                        		
		                        			Hypertension
		                        			;
		                        		
		                        			Hypertension, Renal
		                        			;
		                        		
		                        			NG-Nitroarginine Methyl Ester
		                        			;
		                        		
		                        			Nitric Oxide
		                        			;
		                        		
		                        			Nitric Oxide Synthase
		                        			;
		                        		
		                        			Phenylephrine
		                        			;
		                        		
		                        			Placebos
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Relaxation
		                        			;
		                        		
		                        			Renal Artery
		                        			;
		                        		
		                        			Salicylamides
		                        			;
		                        		
		                        			Vasodilation
		                        			
		                        		
		                        	
6.ABO Genotyping of a Neonate with Mixed Field Agglutination.
Ju Yeon KIM ; Hanui KIM ; Jae Yeoul CHOI ; Yoon Ho KIM ; Jang Su KIM ; Myung Han KIM ; Young Ki KIM ; Kap No LEE ; Chae Seung LIM
Korean Journal of Blood Transfusion 2011;22(2):171-176
		                        		
		                        			
		                        			Mixed field agglutination is an important, but rare phenomenon of ABO blood grouping. Contrary to adults, neonatal red blood cells are immature and they present a weak ABO expression, and sometimes this result in a mixed field agglutination pattern. We report here on a case of a neonate who presented with mixed field agglutination on the ABO blood grouping during serologic testing and the neonate had a normal ABO genotype.
		                        		
		                        		
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Agglutination
		                        			;
		                        		
		                        			Blood Grouping and Crossmatching
		                        			;
		                        		
		                        			Erythrocytes
		                        			;
		                        		
		                        			Genotype
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Infant, Newborn
		                        			;
		                        		
		                        			Serologic Tests
		                        			
		                        		
		                        	
7.Evaluation of ABO Antibody Titration Using Tube and Column Agglutination Techniques.
Chi Hyun CHO ; Ha Nui KIM ; Seung Gyu YUN ; Gye Ryung CHOI ; Jae Yeoul CHOI ; Jang Su KIM ; Chae Seung LIM ; Young kee KIM ; Kap No LEE
Laboratory Medicine Online 2011;1(1):57-63
		                        		
		                        			
		                        			BACKGROUND: ABO antibody titration is useful for the evaluation of ABO-incompatible bone marrow or solid organ transplantations, yet the results quite vary between different test methods used. We compared the results of microcolumn agglutination and tube methods. METHODS: Anti-A and anti-B isoagglutionin titers were determined in 63 healthy individuals (23 O, 20 A, and 20 B blood groups) using 4 different methods: immediate spin tube (tube), microcolumn agglutination without anti-human globulin (AHG) (CAT), tube with AHG (tube-AHG) and microcolumn agglutination with AHG (CAT-AHG). RESULTS: The median (range) titers of anti-A and anti-B in group O individuals by tube, CAT, tube-AHG, and CAT-AHG methods were 64 (8-512), 64 (8-512), 128 (8-2,048), and 128 (16-2,048); 64 (16-128), 128 (16-256), 128 (16-512), and 256 (16-512), respectively. The median (range) titers of anti-A in group B and anti-B in group A individuals by the four methods were 64 (16-128), 128 (8-128), 128 (8-256), and 256 (8-256); 64 (8-128), 64 (8-128), 32 (8-128), and 64 (8-256), respectively. The isoagglutinin titer measured by CAT-AHGmethod was the highest. The titers measured by CAT and CAT-AHG methods were 0-1 titer higher than those by tube and tube-AHG methods, respectively. Whatever method was used, the isoagglutinin titers were higher in women than in men. CONCLUSIONS: CAT-AHG was the most sensitive method among the four methods tested. Since AHG titer values are critical for the clinical management and CAT has less manual procedures than tube method, CAT-AHG method could be used for the standardization of ABO antibody titration in different institutions.
		                        		
		                        		
		                        		
		                        			Agglutination
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Bone Marrow
		                        			;
		                        		
		                        			Cats
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Organ Transplantation
		                        			;
		                        		
		                        			Transplants
		                        			
		                        		
		                        	
8.Direct Vascular Actions of Indapamide in Aorta from Renal Hypertensive Rats.
Seok CHOI ; Hee Wook WHI ; Mi Jung LEE ; Jae Yeoul JUN ; Hyun Lee KIM ; Jong Hoon CHUNG ; Hye Rang SHIN ; Hyun Jung OH ; Cheol Ho YEUM
Korean Journal of Nephrology 2011;30(5):459-467
		                        		
		                        			
		                        			PURPOSE: Thiazide diuretics exert their hypotensive efficacy through a combined vasodilator and diuretic effect. The present study was conducted to assess the inhibitory effect of thiazide diuretic, hydrochlorothiazide, and the thiazide-like diuretics, indapamide and chlorthalidone on contractile responses to norepinephrine and arginine vasopressin in aortic rings from 2K1C renal hypertensive and sham-clipped normotensive rats. METHODS: 2K1C hypertension was made by clipping the left renal artery and age-matched control rats received a sham treatment. Changes in the tension of aortic ring preparations were measured isometrically. RESULTS: Indapamide inhibits the contractile responses to norepinephrine and vasopressin in aortic rings from 2K1C rats, while it did not modify in control rats. The inhibitory effect of indapamide was abolished by endothelium removal. Hydrochlorothiazide or chlorthalidone did not affect the vasoconstriction induced by norepinephrine and vasopressin either in sham or in 2K1C hypertensive rats. CONCLUSION: These results suggest that indapamide inhibits the contractile responses to norepinephrine and vasopressin via an endothelium-dependent mechanism in 2K1C renal hypertension.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Aorta
		                        			;
		                        		
		                        			Arginine Vasopressin
		                        			;
		                        		
		                        			Chlorthalidone
		                        			;
		                        		
		                        			Diuretics
		                        			;
		                        		
		                        			Endothelium
		                        			;
		                        		
		                        			Hydrochlorothiazide
		                        			;
		                        		
		                        			Hypertension
		                        			;
		                        		
		                        			Hypertension, Renal
		                        			;
		                        		
		                        			Indapamide
		                        			;
		                        		
		                        			Norepinephrine
		                        			;
		                        		
		                        			Placebos
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Renal Artery
		                        			;
		                        		
		                        			Salicylamides
		                        			;
		                        		
		                        			Sodium Chloride Symporter Inhibitors
		                        			;
		                        		
		                        			Vasoconstriction
		                        			;
		                        		
		                        			Vasodilation
		                        			;
		                        		
		                        			Vasopressins
		                        			
		                        		
		                        	
9.Interplay of Hydrogen Sulfide and Nitric Oxide on the Pacemaker Activity of Interstitial Cells of Cajal from Mouse Small Intestine
Pyung Jin YOON ; Shanker Prasad PARAJULI ; Dong Chuan ZUO ; Pawan Kumar SHAHI ; Hyung Jung OH ; Hae Rang SHIN ; Mi Jung LEE ; Cheol Ho YEUM ; Seok CHOI ; Jae Yeoul JUN
Chonnam Medical Journal 2011;47(2):72-79
		                        		
		                        			
		                        			We studied whether nitric oxide (NO) and hydrogen sulfide (H2S) have an interaction on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine. The actions of NO and H2S on pacemaker activities were investigated by using the whole-cell patch-clamp technique and intracellular Ca2+ analysis at 30degrees C in cultured mouse ICC. Exogenously applied (+/-)-S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, or sodium hydrogen sulfide (NaHS), a donor of H2S, showed no influence on pacemaker activity (potentials and currents) in ICC at low concentrations (10 microM SNAP and 100 microM NaHS), but SNAP or NaHS completely inhibited pacemaker amplitude and pacemaker frequency with increases in the resting currents in the outward direction at high concentrations (SNAP 100 microM and NaHS 1 mM). Co-treatment with 10 microM SNAP plus 100 microM NaHS also inhibited pacemaker amplitude and pacemaker frequency with increases in the resting currents in the outward direction. ODQ, a guanylate cyclase inhibitor, or glibenclamide, an ATP-sensitive K+ channel inhibitor, blocked the SNAP+NaHS-induced inhibition of pacemaker currents in ICC. Also, we found that SNAP+NaHS inhibited the spontaneous intracellular Ca2+ ([Ca2+]i) oscillations in cultured ICC. In conclusion, this study describes the enhanced inhibitory effects of NO plus H2S on ICC in the mouse small intestine. NO+H2S inhibited the pacemaker activity of ICC by modulating intracellular Ca2+. These results may be evidence of a physiological interaction of NO and H2S in ICC for modulating gastrointestinal motility.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Gastrointestinal Motility
		                        			;
		                        		
		                        			Glyburide
		                        			;
		                        		
		                        			Guanylate Cyclase
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Hydrogen
		                        			;
		                        		
		                        			Hydrogen Sulfide
		                        			;
		                        		
		                        			Interstitial Cells of Cajal
		                        			;
		                        		
		                        			Intestine, Small
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Nitric Oxide
		                        			;
		                        		
		                        			Patch-Clamp Techniques
		                        			;
		                        		
		                        			Sodium
		                        			;
		                        		
		                        			Sulfides
		                        			;
		                        		
		                        			Tissue Donors
		                        			
		                        		
		                        	
10.5-Hydroxytryptamine Generates Tonic Inward Currents on Pacemaker Activity of Interstitial Cells of Cajal from Mouse Small Intestine.
Pawan Kumar SHAHI ; Seok CHOI ; Dong Chuan ZUO ; Cheol Ho YEUM ; Pyung Jin YOON ; Jun LEE ; Young Dae KIM ; Chan Guk PARK ; Man Yoo KIM ; Hye Rang SHIN ; Hyun Jung OH ; Jae Yeoul JUN
The Korean Journal of Physiology and Pharmacology 2011;15(3):129-135
		                        		
		                        			
		                        			In this study we determined whether or not 5-hydroxytryptamine (5-HT) has an effect on the pacemaker activities of interstitial cells of Cajal (ICC) from the mouse small intestine. The actions of 5-HT on pacemaker activities were investigated using a whole-cell patch-clamp technique, intracellular Ca2+ ([Ca2+]i) analysis, and RT-PCR in ICC. Exogenously-treated 5-HT showed tonic inward currents on pacemaker currents in ICC under the voltage-clamp mode in a dose-dependent manner. Based on RT-PCR results, we found the existence of 5-HT2B, 3, 4, and 7 receptors in ICC. However, SDZ 205557 (a 5-HT4 receptor antagonist), SB 269970 (a 5-HT7 receptor antagonist), 3-tropanylindole - 3 - carboxylate methiodide (3-TCM; a 5-HT3 antagonist) blocked the 5-HT-induced action on pacemaker activity, but not SB 204741 (a 5-HT2B receptor antagonist). Based on [Ca2+]i analysis, we found that 5-HT increased the intensity of [Ca2+]i. The treatment of PD 98059 or JNK II inhibitor blocked the 5-HT-induced action on pacemaker activity of ICC, but not SB 203580. In summary, these results suggest that 5-HT can modulate pacemaker activity through 5-HT3, 4, and 7 receptors via [Ca2+]i mobilization and regulation of mitogen-activated protein kinases.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Flavonoids
		                        			;
		                        		
		                        			Gastrointestinal Motility
		                        			;
		                        		
		                        			Imidazoles
		                        			;
		                        		
		                        			Interstitial Cells of Cajal
		                        			;
		                        		
		                        			Intestine, Small
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Mitogen-Activated Protein Kinases
		                        			;
		                        		
		                        			para-Aminobenzoates
		                        			;
		                        		
		                        			Patch-Clamp Techniques
		                        			;
		                        		
		                        			Phenols
		                        			;
		                        		
		                        			Pyridines
		                        			;
		                        		
		                        			Receptor, Serotonin, 5-HT2B
		                        			;
		                        		
		                        			Receptors, Serotonin
		                        			;
		                        		
		                        			Receptors, Serotonin, 5-HT4
		                        			;
		                        		
		                        			Serotonin
		                        			;
		                        		
		                        			Sulfonamides
		                        			
		                        		
		                        	
            
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