To investigate 1alpha,25-(OH)2D3 regulation of matrix metalloproteinase-9 (MMP-9) protein expression during osteoclast formation and differentiation, receptor activator of nuclear factor kappaB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) were administered to induce the differentiation of RAW264.7 cells into osteoclasts. The cells were incubated with different concentrations of 1alpha,25-(OH)2D3 during culturing, and cell proliferation was measured using the methylthiazol tetrazolium method. Osteoclast formation was confirmed using tartrate-resistant acid phosphatase (TRAP) staining and assessing bone lacunar resorption. MMP-9 protein expression levels were measured with Western blotting. We showed that 1alpha,25-(OH)2D3 inhibited RAW264.7 cell proliferation induced by RANKL and M-CSF, increased the numbers of TRAP-positive osteoclasts and their nuclei, enhanced osteoclast bone resorption, and promoted MMP-9 protein expression in a concentration-dependent manner. These findings indicate that 1alpha,25-(OH)2D3 administered at a physiological relevant concentration promoted osteoclast formation and could regulate osteoclast bone metabolism by increasing MMP-9 protein expression during osteoclast differentiation.
Acid Phosphatase/metabolism ; Animals ; Blotting, Western ; Calcitriol/*pharmacology ; Calcium Channel Agonists/pharmacology ; *Cell Differentiation ; Cell Line ; Cell Proliferation ; Gene Expression Regulation, Enzymologic/*drug effects ; Isoenzymes/metabolism ; Matrix Metalloproteinase 9/*genetics/metabolism ; Mice ; Osteoclasts/*cytology/*enzymology ; Tetrazolium Salts ; Thiazoles

Animals ; Bone Density Conservation Agents ; pharmacology ; Calcitriol ; pharmacology ; Calcium Channel Agonists ; pharmacology ; Humans ; Pulmonary Fibrosis ; metabolism ; Signal Transduction ; drug effects ; Transforming Growth Factor beta ; metabolism ; Wnt Proteins ; metabolism

The metastatic calcification is defined as the deposition of calcium salt in normal tissue with an abnormal serum biochemical environment, such as chronic kidney disease, hyperparathyroidism, and hypercalcemia related with malignancy. Although the metastatic calcification can develop in any organs and tissues, presenting its symptoms and complications are rare. Thus a few cases have been reported. This case shows the metastatic calcification of the small intestine without any peritoneal and mesenteric vascular calcification which was early diagnosed by computed tomography and mesenteric angiography in a patient with abdominal pain, receiving continuous ambulatory peritoneal dialysis due to end stage renal disease. The clinician should early consider the metastatic calcification as differential diagnosis when unidentified calcifications are noted in simple abdominal X-ray such as in the present case, and promptly confirm it by using appropriate diagnostic tests in order to prevent its complications and progression.
Calcinosis/*diagnosis/drug therapy/etiology ; Calcitriol/therapeutic use ; Calcium/blood ; Calcium Carbonate/therapeutic use ; Calcium Channel Agonists/therapeutic use ; Humans ; Intestine, Small/*radiography ; Kidney Failure, Chronic/therapy ; Male ; Mesenteric Artery, Superior/radiography ; Middle Aged ; Peritoneal Dialysis, Continuous Ambulatory/*adverse effects ; Tomography, X-Ray Computed

BACKGROUNDIt has been reported that endogenous or exogenous hydrogen sulfide (H(2)S) exerts physiological effects in the vertebrate cardiovascular system. We have also demonstrated that H(2)S acts as an important regulator of electrophysiological properties in guinea pig papillary muscles and on pacemaker cells in sinoatrial nodes of rabbits. This study was to observe the electrophysiological effects of H(2)S on human atrial fibers.

METHODSHuman atrial samples were collected during cardiac surgery. Parameters of action potential in human atrial specialized fibers were recorded using a standard intracellular microelectrode technique.

RESULTSNaHS (H(2)S donor) (50, 100 and 200 µmol/L) decreased the amplitude of action potential (APA), maximal rate of depolarization (V(max)), velocity of diastolic (phase 4) depolarization (VDD) and rate of pacemaker firing (RPF), and shortened the duration of 90% repolarization (APD(90)) in a concentration-dependent manner. ATP-sensitive K(+) (K(ATP)) channel blocker glibenclamide (Gli, 20 µmol/L) partially blocked the effects of NaHS (100 µmol/L) on human atrial fiber cells. The L-type Ca(2+) channel agonist Bay K8644 (0.5 µmol/L) also partially blocked the effects of NaHS (100 µmol/L). An inhibitor of cystathionine γ-lyase (CSE), DL-propargylglycine (PPG, 200 µmol/L), increased APA, V(max), VDD and RPF, and prolonged APD(90).

CONCLUSIONSH(2)S exerts a negative chronotropic action and accelerates the repolarization of human atrial specialized fibers, possibly as a result of increases in potassium efflux through the opening of K(ATP) channels and a concomitant decrease in calcium influx. Endogenous H(2)S may be generated by CSE and act as an important regulator of electrophysiological properties in human atrial fibers.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Action Potentials ; drug effects ; Calcium Channel Agonists ; pharmacology ; Calcium Channels, L-Type ; metabolism ; Cystathionine gamma-Lyase ; metabolism ; Electrophysiology ; methods ; Glyburide ; pharmacology ; Heart Atria ; drug effects ; metabolism ; Humans ; Hydrogen Sulfide ; metabolism ; In Vitro Techniques ; KATP Channels ; antagonists & inhibitors ; metabolism ; Sulfides ; pharmacology

Sildenafil increases the cyclic guanosine monophosphate (cGMP) by inhibition of a phosphodiesterase 5, thereby leading to an antinociceptive effect. The increased cGMP may exert the effect on an L-type calcium channel through the activation of protein kinase G (PKG). The purpose of this study was to examine the possible involvement of a PKG-L-type calcium channel on the effect of sildenafil at the spinal level. Catheters were inserted into the intrathecal space of male SD rats. Pain was induced by applying 50 microliter of a 5% formalin solution to the hindpaw. The sildenafil-induced effect was examined after an intrathecal pretreatment of a PKG inhibitor (KT 5823), or a L-type calcium channel activator (FPL 64176). Intrathecal sildenafil produced an antinociceptive effect during phase 1 (0~10 min interval) and phase 2 (10~60 min interval) in the formalin test. Intrathecal KT 5823 and FPL 64176 attenuated the antinociceptive effect of sildenafil during both phases. Sildenafil is effective against both acute pain and the facilitated pain state at the spinal level. In addition, the inhibition of an L-type calcium channel by activation of the PKG may contribute to the antinocieptive mechanism of sildenafil in the spinal cord.
Animals ; Calcium Channel Agonists/pharmacology ; Calcium Channels, L-Type/*physiology ; Carbazoles/pharmacology ; Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors/*physiology ; Dose-Response Relationship, Drug ; Male ; Pain/drug therapy/*physiopathology ; Pain Measurement ; Piperazines/*pharmacology/therapeutic use ; Protein Kinase Inhibitors/pharmacology ; Purines/pharmacology/therapeutic use ; Pyrroles/pharmacology ; Rats ; Rats, Sprague-Dawley ; Sulfones/*pharmacology/therapeutic use

Trigeminal neuralgia is a paroxysmal disorder with severely disabling facial pain and thus continues to be a real therapeutic challenge. At present there are few effective drugs for treatment of this pain. The present study was aimed to explore the involvement of BK(Ca) channels and Kv channels in the mechanical allodynia in a rat model of trigeminal neuropathic pain. Here the effectiveness of drug target injection at the trigeminal ganglion through the infraorbital foramen was first evaluated by immunofluorescence and animal behavior test. Trigeminal neuropathic pain model was established by chronic constriction injury of the infraorbital nerve (ION-CCI) in rats. BK(Ca) channel agonist and Kv channel antagonist were administered into the trigeminal ganglion in ION-CCI rats and sham rats by the above target injection method, and the facial mechanical pain threshold was measured. The results showed that the drug could accurately reach the trigeminal ganglion by target injection which was more effective than that by the normal injection around infraorbital foramen. Rats suffered significant mechanical allodynia in the whisker pad of the operated side from 6 d to 42 d after ION-CCI. BK(Ca) channel agonist NS1619 significantly and dose-dependently attenuated the facial mechanical allodynia and increased the facial mechanical pain threshold in ION-CCI rats 15 d after operation. Kv antagonist 4-AP was able to reduce the threshold in ION-CCI rats when facial mechanical threshold was partly recovered and relatively stable on the 35th day after operation. These results suggest that BK(Ca) channel agonist NS1619 and Kv channel antagonist 4-AP can significantly affect the rats' facial mechanical pain threshold after ION-CCI. Activation of BK(Ca) channels may be related to the depression of the primary afferent neurons in trigeminal neuropathic pain pathways. Activation of Kv channels may exert a tonic inhibition on the trigeminal neuropathic pain.
4-Aminopyridine ; administration & dosage ; Animals ; Benzimidazoles ; administration & dosage ; Constriction ; Facial Pain ; physiopathology ; Injections, Intralesional ; Kv1.4 Potassium Channel ; antagonists & inhibitors ; Large-Conductance Calcium-Activated Potassium Channels ; agonists ; Male ; Orbit ; innervation ; Pain Threshold ; physiology ; Rats ; Rats, Sprague-Dawley ; Trigeminal Ganglion ; drug effects ; Trigeminal Neuralgia ; drug therapy ; physiopathology

OBJECTIVE: To explore the protective effect of calcium channel agonist BayK8644 preconditioning on the lungs against ischemia-reperfusion injury (I/R) and its mechanism in rabbits. METHODS: Forty rabbits were randomly divided into 4 groups (10 in each group): a sham-operated group (Sham), an I/R group (I/R), an ischemic preconditioning (IP) group (IP), and a BayK8644 preconditioning group(BayK8644).The wet to dry weight (W/D) ratio, superoxide dismutase (SOD) activity, myleoperoxidase (MPO), and malondialdehyde (MDA) contents of the lung tissues were measured after the operation. Morphological and ultrastructural changes of the lung tissue were observed by light and electron microscope. The expression of pulmonary surfactant-associated protein-A (SP-A) was examined with immunohistochemistry. RESULTS: The W/D ratio, MPO and MDA contents of the lung tissue in the BayK8644 group and IP group were significantly lower than those in the I/R group (P<0.05), while the SOD activity and expression of SP-A of the lung tissue in the BayK8644 group and IP group were significantly higher than those in the I/R group(P<0.05), The morphological changes and ultrastructural changes were less notable in the BayK8644 group and IP group, compared with the I/R group. There was no significant difference in SOD activity, MPO and MDA contents between the BayK8644 group and IP group (P>0.05). CONCLUSION Appropriate BayK8644 preconditioning can induce transient Ca²+ influx, and elicit strong protection against the lung ischemia-reperfusion injury, which can simulate the endogenous protective effect of ischemic preconditioning.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Animals ; Calcium Channel Agonists ; pharmacology ; Female ; Ischemic Preconditioning ; methods ; Lung ; blood supply ; Male ; Rabbits ; Random Allocation ; Reperfusion Injury ; prevention & control

BACKGROUND: Preterm birth is a major cause of perinatal morbidity and mortality. Tocolytic drugs are used to suppress uterine contractions. The most widely used tocolytics in the Philippines are betamimetics, such as Terbutaline, which are known to have high incidence of maternal adverse effects. Nifedipine, a calcium channel blocker, is an alternative tocolytic with potentially similar efficacy and fewer maternal side effects than terbutaline.
CONCLUSION: Terbutaline and Nifedipine appeared to be equally effective tocolytic agents. However, nifedipine had tile advantage of lesser incidence of maternal adverse effects.

Human ; Tocolytic Agents ; Nifedipine ; Terbutaline ; Calcium Channel Blockers ; Uterine Contraction ; Adrenergic Beta-agonists ; Maternal Inheritance ; Iatrogenic Disease

To study the role of resveratrol in the discharges of neurons in paraventricular nucleus (PVN) in hypothalamic slices, extracellular single-unit discharge recording technique was used. The effects of resveratrol were examined with glass microelectrodes in the rat PVN neurons at resting potential level. The results were as follows: (1) In response to the application of resveratrol (0.05, 0.5, 5.0 μmol/L, n=29) to the superfusate for 2 min, the spontaneous discharge rate (SDR) of neurons in 28/29 (96.6%) hypothalamic slices significantly decreased in a dose-dependent manner; (2) Pretreatment with L-glutamate (0.2 mmol/L) led to a marked increase in the SDR in all 8/8 (100%) slices in an epileptiform pattern. The increased discharges were suppressed by the application of resveratrol (5.0 mmol/L) in all 8 slices; (3) In 8 slices, perfusion of the selective L-type calcium channel agonist, Bay K8644 (0.1 μmol/L), induced a significant increase in the discharge rate in 8/8 (100%) slices. Resveratrol (5.0 μmol/L) significantly attenuated the increased SDR in all 8 slices; (4) Pretreatment with the nitric oxide synthase (NOS) inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME, 50 μmol/L) increased SDR in 7/8 (87.5%) slices, but did not affect the inhibitory effect of resveratrol (5.0 μmol/L). These results suggest that resveratrol inhibits the electrical activity of PVN neurons and exerts neuroprotective actions on central neurons. The inhibitory effect of resveratrol is possibly related to the blockade of L-type calcium channel, but not due to NO release.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Action Potentials ; Animals ; Calcium Channel Agonists ; pharmacology ; Calcium Channels, L-Type ; metabolism ; Glutamic Acid ; pharmacology ; In Vitro Techniques ; Microelectrodes ; NG-Nitroarginine Methyl Ester ; pharmacology ; Neurons ; drug effects ; Paraventricular Hypothalamic Nucleus ; cytology ; Rats ; Rats, Sprague-Dawley ; Stilbenes ; pharmacology

The effects of ginkgolide B on the carotid sinus baroreflex (CSB) were studied in the perfused isolated carotid sinus of 30 anesthetized Sprague-Dawley male rats. The results were as follows. (1) By perfusing with ginkgolide B (0.1, 1, 10 μmol/L), the functional curve of the baroreflex was shifted to the right and upward. There was a marked decrease in peak slope (PS) and reflex decrease (RD) in mean arterial pressure (P<0.01), while the threshold pressure (TP), equilibrium pressure (EP) and saturation pressure (SP) were significantly increased (P<0.05, P<0.01). Among the functional parameters of CSB, the changes in PS, RD, TP, EP and SP were dose-dependent. (2) Pretreatment with Bay K8644 (500 nmol/L), an agonist of L-type calcium channel, completely eliminated the effects of ginkgolide B (1 μmol/L) on the CSB. (3) Pretreatment with tetraethylammonium (TEA, 1 mmol/L), an inhibitor of potassium channel, completely abolished the above effects of ginkgolide B (1 μmol/L) on the CSB. These results suggest that ginkgolide B inhibits the CSB in anesthetized rats, which is mediated by decreased calcium influx and increased potassium efflux in baroreceptor nerve endings.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester ; pharmacology ; Animals ; Baroreflex ; drug effects ; Calcium Channel Agonists ; pharmacology ; Calcium Channels, L-Type ; Carotid Sinus ; physiopathology ; Ginkgolides ; pharmacology ; Lactones ; pharmacology ; Male ; Potassium Channel Blockers ; pharmacology ; Pressoreceptors ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tetraethylammonium ; pharmacology