1.Compound K attenuates glucose intolerance and hepatic steatosis through AMPK-dependent pathways in type 2 diabetic OLETF rats.
Yoo Cheol HWANG ; Da Hee OH ; Moon Chan CHOI ; Sang Yeoul LEE ; Kyu Jeong AHN ; Ho Yeon CHUNG ; Sung Jig LIM ; Sung Hyun CHUNG ; In Kyung JEONG
The Korean Journal of Internal Medicine 2018;33(2):347-355
BACKGROUND/AIMS: Non-alcoholic fatty liver disease is associated with insulin resistance. Compound K (CK) is the final metabolite of panaxadiol ginsenosides that have been shown to exert antidiabetic effects. However, the molecular mechanism of the antidiabetic effects in the liver have not been elucidated; further, whether CK has beneficial effects in hepatosteatosis remains unclear. Therefore, we evaluated the effect of CK on hepatosteatosis as well as its mechanism in high-fat diet (HFD)-fed type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. METHODS: Twenty-four-week-old male OLETF rats were assigned to four groups: control (saline), CK 10 mg/kg, CK 25 mg/kg, or metformin 300 mg/kg (positive control); all treatments were administered orally for 12 weeks. RESULTS: Fasting glucose levels of the CK25 group were significantly lower than those of the control group during the 12 weeks. The results of the oral glucose tolerance test showed that both the glucose concentration after glucose loading and the fasting insulin levels of the CK25 group were significantly lower than those of the control. Hepatosteatosis was significantly improved by CK25. CK25 and metformin significantly increased the phosphorylation of hepatic adenosine monophosphate-activated protein kinase (AMPK). CK25 significantly inhibited the expression of sterol regulatory element-binding protein-1c and fatty acid synthase, while upregulating that of peroxisome proliferator-activated receptor-α and carnitine palmitoyltransferase-1. CONCLUSIONS: CK improved glucose intolerance and hepatosteatosis in HFD-fed OLETF rats through AMPK activation, which has dual mode of action that involves decreasing the synthesis of fatty acids and increasing fatty acid oxidation.
Adenosine
;
AMP-Activated Protein Kinases
;
Animals
;
Carnitine
;
Diabetes Mellitus, Type 2
;
Diet, High-Fat
;
Fasting
;
Fatty Acids
;
Ginsenosides
;
Glucose Intolerance*
;
Glucose Tolerance Test
;
Glucose*
;
Humans
;
Insulin
;
Insulin Resistance
;
Liver
;
Male
;
Metformin
;
Non-alcoholic Fatty Liver Disease
;
Peroxisomes
;
Phosphorylation
;
Protein Kinases
;
Rats
;
Rats, Inbred OLETF*
2.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
3.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
4.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
5.Identification of ATP-sensitive K+ Conductances in Male Rat Major Pelvic Ganglion Neurons.
Kyu Sang PARK ; Seung Kyu CHA ; Keon Il LEE ; Jae Yeoul JUN ; Seong Woo JEONG ; In Deok KONG ; Joong Woo LEE
The Korean Journal of Physiology and Pharmacology 2002;6(5):247-254
Major pelvic ganglia (MPG) neurons are classified into sympathetic and parasympathetic neurons according to the electrophysiological properties; membrane capacitance (Cm), expression of T-type Ca2+ channels, and the firing patterns during depolarization. In the present study, function and molecular expression of ATP-sensitive K+ (K(ATP)) channels was investigated in MPG neurons of male rats. Only in parasympathetic MPG neurons showing phasic firing patterns, hyperpolarizing changes were elicited by the application of diazoxide, an activator of K(ATP) channels. Glibenclamide (10microM), a K(ATP) channel blocker, completely abolished the diazoxide-induced hyperpolarization. Diazoxide increased inward currents at high K+ (90 mM) external solution, which was also blocked by glibenclamide. The metabolic inhibition by the treatment with mitochondrial respiratory chain inhibitors (rotenone and antimycin) hyperpolarized the resting membrane potential of parasympathetic neurons, which was not observed in sympathetic neurons. The hyperpolarizing response to metabolic inhibition was partially blocked by glibenclamide. RT-PCR analysis revealed that MPG neurons mainly expressed the K(ATP) channel subunits of Kir6.2 and SUR1. Our results suggest that MPG neurons have K(ATP) channels, mainly formed by Kir6.2 and SUR1, with phenotype-specificity, and that the conductance through this channel in parasympathetic neurons may contribute to the changes in excitability during hypoxia and/or metabolic inhibition.
Animals
;
Anoxia
;
Diazoxide
;
Electron Transport
;
Fires
;
Ganglia
;
Ganglion Cysts*
;
Glyburide
;
Humans
;
Male*
;
Membrane Potentials
;
Membranes
;
Neurons*
;
Rats*
6.MR Findings of Spinal Cord in Decompression Sickness.
Ga Yeoul OH ; In Cheol CHO ; Sang Tae KIM ; Jin Yong KIM ; Ki Hong KIM ; Chun Hwan HAN ; Shi Kyung LEE
Journal of the Korean Radiological Society 2001;45(2):133-137
PURPOSE: To determine the MR imaging findings of spinal cord decompression sickness. MATERIALS AND METHODS: We retrospectively analysed the spinal MR images of eight patients (M : 6, F : 2) with decompression sickness affecting the cervical spine (n=1) or thoracic spine (n=7). The observed extent, location, continuity, signal intensity and contrast enhancement pattern of spinal cord lesions were analysed. RESULTS: The chief MR finding was continuous (n=2) or non-continuous (n=3) high signal intensity on T2-weighted images in the posterior paramedian spinal cord. In three cases, additional T2 signal abnormality in the ventral horn of the gray matter was observed. There was no signal intensity abnormality on T1- weighted images or abnormal enhancement on post-Gadolinium T1-weighted images. In one case, cord swelling in addition to T2 signal abnormality was observed. CONCLUSION: MR imaging is useful for evaluating spinal cord lesions in patients with decompression sickness.
Animals
;
Decompression Sickness*
;
Decompression*
;
Horns
;
Humans
;
Magnetic Resonance Imaging
;
Retrospective Studies
;
Spinal Cord*
;
Spine
7.A Pitfall in the Diagnosis of Bilateral Choanal Atresia: A Case Report.
Sang Tae KIM ; Shi Kyung LEE ; Eun Jin RHO ; Ga Yeoul OH ; Jin Yong KIM ; Ki Hong KIM ; Chun Hwan HAN ; Young Min AHN
Journal of the Korean Radiological Society 2001;44(3):389-391
Choanal atresia is a rare congenital anomaly involving unilateral or bilateral posterior nasal choanal obstruction. Multiple associated anomalies have been described. We describe the case of a 1-month-old boy with bilateral choanal atresia, misdiagnosed after CT as a midline meningocele because the floor of the midline anterior cranial fossa was not ossified and secretion had accumulated in the obstructed posterior nasal choana.
Choanal Atresia*
;
Cranial Fossa, Anterior
;
Diagnosis*
;
Humans
;
Infant, Newborn
;
Male
;
Meningocele
8.Interdural Cyst of the Thoracolumbar Region.
Sang Tae KIM ; Chun Hwan HAN ; Seong Whi CHO ; Jong Chan LEE ; Ga Yeoul OH ; Jin Yong KIM
Journal of the Korean Radiological Society 2000;43(3):357-360
Spinal interdural cyst is an extremely rare lesion, the wall of which consists of a dura-like layer without arachnoid. This report describes two cases in which patients with interdural cysts of the thoracolumbar spine presented with atypical neurologic signs and symptoms, including lower back pain and radiating pian in both lower extremities. Plain radiographs, CT myelograms and magnetic resonance images were obtained, but the cysts could not be differentiated from extradural arachnoid cyst. Surgical intervention revealed a dura-like layer of cyst wall, and within the cyst, a fluid resembling cerebrospinal fluid was present. In one case, microscopic examination showed that fragments of connective tissue without an arachnoid lining formed a thin fibrous cystic wall, a finding consistent with meningeal cyst.
Arachnoid
;
Cerebrospinal Fluid
;
Connective Tissue
;
Humans
;
Low Back Pain
;
Lower Extremity
;
Neurologic Manifestations
;
Spine
9.Neurotensin enhances gastric motility in antral circular muscle strip of guinea-pig..
Tae Yong KOH ; Sung Joon KIM ; Sang Jin LEE ; Tong Mook KANG ; Jun Jae YEOUL ; Jae Hoon SIM ; Insuk SO ; Ki Whan KIM
The Korean Journal of Physiology and Pharmacology 2000;4(3):227-234
Many reports suggest that neurotensin (NT) in the gastrointestinal tract may play a possible role as a neurotransmitter, a circulating hormone, or a modulator of motor activity. NT exerts various actions in the intestine; it produces contractile and relaxant responses in intestinal smooth muscle. This study was designed to investigate the effect of NT on motility of antral circular muscle strips in guinea-pig stomach. To assess the role of Ca2+ influx in underlying mechanism, slow waves were simultaneously recorded with spontaneous contractions using conventional intracellular mircoelectrode technique. At the concentration of 10-7 M, where NT showed maximum response, NT enhanced the magnitude (863 +/- 198%, mean +/- SEM, n = 13) and the frequency (154 +/- 10.3%, n = 11) of spontaneous contractions. NT evoked a slight hyperpolarization of membrane potential, tall and steep slow waves with abortive spikes (278 +/- 50%, n = 4). These effects were not affected by atropine (2 micrometer), guanethidine (2 micrometer) and tetrodotoxin (0.2 micrometer). NT-induced contractile responses were abolished in Ca2+-free solution and reduced greatly to near abolition by 10 micrometer of verapamil or 0.2 mM of CdCl2. Verapamil attenuated the effects of NT on frequency and amplitude of the slow waves. Taken together, these results indicate that NT enhances contractility in guinea-pig gastric antral circular muscle and Ca2+ influx through the voltage-operated Ca2+ channel appears to play an important role in the NT-induced contractile mechanism.
Atropine
;
Cadmium Chloride
;
Gastrointestinal Tract
;
Guanethidine
;
Intestines
;
Membrane Potentials
;
Motor Activity
;
Muscle, Smooth
;
Neurotensin*
;
Neurotransmitter Agents
;
Stomach
;
Tetrodotoxin
;
Verapamil
10.MR Imaging with FLAIR Pulse Sequence in Various Cerebral Lesions: Comparison with T2-Weighted Imaging.
Yu Jin LEE ; Chun Hwan HAN ; Jong Chan LEE ; Sang Tae KIM ; Ga Yeoul OH ; Seong Whi CHO ; Shi Kyung LEE ; Ju Hyuk LEE
Journal of the Korean Radiological Society 1998;38(3):397-401
PURPOSE: To evaluate the utility of fluid-attenuated inversion recovery(FLAIR) sequence by comparing thesignal intensities in various cerebral lesions with those on T2-weighted MR imaging. MATERIALS & METHODS: In 41patients who showed different signal intensities between T2-weighted images and FLAIR sequences, we reviewed theVirchow-Robin space(VRS), acute or chronic infarctions including lacunar cavities, and postoperativeencephalomalacia. In all patients, the location, shape and size of abnormal signal intensities were evaluated. RESULTS: The hyperintensities of VRS and lacunar infarctions on T2-weighted imaging appeared as hypointensitieson FLAIR imaging. The hyperintense rims or crescents around lacunar cavities were only detected on FLAIR imaging.The extent of acute and chronic infarctions with homogenous hyperintensities seen on T2-weighted images was welldelineated on FLAIR imaging. Postoperative encephalomalacia and adjacent lesions showed low and high signalintensities, respectively, on FLAIR imaging, though they were hyperintense on T2-weighted images. CONCLUSION: ForVRS, infarction and encephalomalacia, FLAIR provides images that are superior to T2-weighted images, and may thusbe useful as an additional MR sequence in various cerebral lesions.
Encephalomalacia
;
Humans
;
Infarction
;
Magnetic Resonance Imaging*
;
Stroke, Lacunar

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