Nitric oxide (NO) has been considered as an important mediator in inflammatory phases and in loss of cartilage. In inflammatory arthritis, NO levels are correlated with disease activity and articular cartilage is able to produce large amounts of NO with the appropriate inducing factor such as cytokines. The old animals are shown to have a greater sensitivity to NO than young animals. This study evaluated the basal production of NO in normal and OA-affected chondroyctes from young and old patients and compared the levels of NO formation in response to IL-1beta. The results showed that the basal levels were 7-fold higher in old chondrocytes than those of young cells. However, the IL-1beta induced NO production was seen to decrease with age. Aminoguianidine (AG), a competitive inhibitor of iNOS, inhibited NO formation completely in both chondrocytes from young and old individuals. However, at the same concentration of AG it caused partial inhibition of NO and iNOS formation in chondrocytes from OA-affected individuals. In addition, although the IL-1beta induced NO production was much lesser than that of young chondrocytes, the inhibition of collagen production by IL-1beta was prominent in old chondrocytes and OA-affected chondrocytes. These results suggest that age-related differences in the regulation of NO production and collagen production, which may affect the ageing cells and osteoarthritic changes in some way.
Aging/*physiology ; Cartilage, Articular/*physiopathology ; Cells, Cultured ; Chondrocytes/*metabolism ; Collagen Type II/metabolism ; Enzyme Inhibitors/pharmacology ; Guanidines/pharmacology ; Human ; Interleukin-1/pharmacology ; Nitric Oxide/*biosynthesis ; Osteoarthritis/*metabolism

Nitric oxide (NO) has been considered as an important mediator in inflammatory phases and in loss of cartilage. In inflammatory arthritis, NO levels are correlated with disease activity and articular cartilage is able to produce large amounts of NO with the appropriate inducing factor such as cytokines. The old animals are shown to have a greater sensitivity to NO than young animals. This study evaluated the basal production of NO in normal and OA-affected chondroyctes from young and old patients and compared the levels of NO formation in response to IL-1beta. The results showed that the basal levels were 7-fold higher in old chondrocytes than those of young cells. However, the IL-1beta induced NO production was seen to decrease with age. Aminoguianidine (AG), a competitive inhibitor of iNOS, inhibited NO formation completely in both chondrocytes from young and old individuals. However, at the same concentration of AG it caused partial inhibition of NO and iNOS formation in chondrocytes from OA-affected individuals. In addition, although the IL-1beta induced NO production was much lesser than that of young chondrocytes, the inhibition of collagen production by IL-1beta was prominent in old chondrocytes and OA-affected chondrocytes. These results suggest that age-related differences in the regulation of NO production and collagen production, which may affect the ageing cells and osteoarthritic changes in some way.
Aging/*physiology ; Cartilage, Articular/*physiopathology ; Cells, Cultured ; Chondrocytes/*metabolism ; Collagen Type II/metabolism ; Enzyme Inhibitors/pharmacology ; Guanidines/pharmacology ; Human ; Interleukin-1/pharmacology ; Nitric Oxide/*biosynthesis ; Osteoarthritis/*metabolism

Animals ; Brain ; metabolism ; Brain Injuries ; metabolism ; Enzyme Inhibitors ; pharmacology ; Guanidines ; pharmacology ; Neuroprotective Agents ; pharmacology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; Rats

Aging ; physiology ; Animals ; Arteries ; physiopathology ; Arteriosclerosis ; physiopathology ; Blood Pressure ; drug effects ; Diabetes Mellitus ; physiopathology ; Glycation End Products, Advanced ; antagonists & inhibitors ; metabolism ; physiology ; Guanidines ; pharmacology ; Humans ; Thiazoles ; pharmacology

OBJECTIVETo investigate the protective effects of Cariporide on immature rabbit heart, and to search for the protective mechanism of the Na(+)/H(+) exchange inhibitor on immature rabbit hearts.

METHODSNew Zealand immature rabbits were randomly divided into two groups (n = 12 in each group). The isolated rabbit heart model was involved in this study. The hearts were submitted to 60 minutes of normothermic ischemia with cardioplegia per 20 minutes of reperfusion. Group I received St. Thomas No2 as cardioprotective solution. Group II received St. Thomas No2 with addition of cariporide (10 micro mol/L). The left ventricular function was recorded, including left ventricular systolic pressure (LVSP), left ventricular dystolic pressure (LVDP), coronary artery flow (CAF), mean aortic pressure (MAP), aortic flow (AF) and dp/dt max. The levels of creatine phosphokinase (CK), lactic dehydrogenase (LDH) of coronary sinus venous solution were measured. The ventricular cardiomyocytes isolated from other 6 immature rabbit hearts were subdivided into 3 groups of each heart, which were attained by means of collagenase-perfusion. All cells were incubated with calcium fluoresence indicator Fluo-3/AM, and then the intracellular free calcium was measured under the laser scanning con-focal microscopy. The baseline was measured after isolation without anoxic/re-oxygenation. The control group received anoxic conditions for 60 minutes and re-oxygenation for 30 minutes, then was measured. The experiment group received the same conditions as control group with addition of Cariporide (1 micromol/L).

RESULTSAfter ischaemia/reperfusion, the percentage of recovery of myocardial function in group II was much better than group I; the LVDP, LVSP, MAP, AF, CAF and dp/dt max showed markedly better recovery in group II. The release of CK, LDH was significantly increased in Group I. After anoxic/re-oxygenation, the intracellular free calcium of isolated immature rabbit ventricular myocytes in control group increased significantly than baseline (P < 0.01); there were no significant difference of immature myocardial [Ca(2+)]i between experiment group and baseline (P > 0.05); and the experiment group myocardial [Ca(2+)]i reduced significantly than control (P < 0.01).

CONCLUSIONSCariporide demonstrates significant cardio-protective effects for immature myocardium ischemia/reperfusion, and the protective mechanism may be due to the inhibition of the intracellular free calcium overload.

Animals ; Arrhythmias, Cardiac ; etiology ; Calcium ; metabolism ; Female ; Guanidines ; pharmacology ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Rabbits ; Sodium ; metabolism ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; Sulfones ; pharmacology

This study was performed to investigate the action of potassium channel openers on the mechanical activity of detrusor muscle isolated from rats. Detrusor muscle strips, 15 mm in length, were myographied isometrically in an isolated organ bath. P 1060, RP 49356 and BRL 38277, potassium channel activators, reduced the basal tone and diminished the phasic activity of detrusor concentration-dependently. P 1060, RP 49356 and BRL 38227 suppressed the maximal responses to bethanechol and shifted the concentration-response curves of bethanechol-induced contraction to the right. RP 49356 and BRL 38227 reduced the contraction by low (20 mM) concentration of potassium. P 1060, however, diminished the high (80 mM) and low (20 mM) concentration of potassium-induced contraction. Glibenclamide, an inhibitor of ATP-dependent potassium channel, antagonized the suppressive action of P 1060, RP 49356 and BRL 38227 on the basal tone. Apamin or procaine did not antagonize it significantly. Based on these results, it is suggested that the relaxation of detrusor muscle strip caused by P 1060, RP 49356 and BRL 38227 may predominantly involve opening of the same potassium channel, i.e., the ATP-dependent potassium channel.
Animals ; Benzopyrans/*pharmacology ; Cromakalim ; Guanidines/*pharmacology ; Muscle Contraction/drug effects ; Muscle, Smooth/*drug effects ; Picolines/*pharmacology ; Potassium Channels/*drug effects ; Pyrans/*pharmacology ; Pyrroles/*pharmacology ; Rats ; Rats, Sprague-Dawley ; Urinary Bladder/*drug effects/physiology

This study was purposed to explore the changes of possible angiogenetic factors other than VEGF after inhibition of NHE1 and their related mechanisms. The K562 cells were treated by NHE1 specific inhibitor cariporide, the angiogenesis factors after inhibition of NHE1 were screened by using protein chip, the IL-8 expression level after cariporide treatment was detected by real-time quantitative PCR; the K562 cells with stable interference of NHE1 were constructed, the IL-8 expression level after interference of NHE1 was detected by real-time quantitative PCR; the p38 phosphorylation level in K562 cells treated with cariporide was detected by Western blot. After treatment of K562 cells with p38 inhibitor SB203580, the IL-8 expression level was decreased by real-time quantitative PCR. The results of protein chip showed that IL-8 expression decreased after cariporide treatment. Real-time quantitative PCR confirmed this inhibitory effect. The p38 phosphorylation level increased after cariporide treatment. The down-regulation of IL-8 expression induced by cariporide treatment was partially restored after K562 cells were treated with p38 inhibitor SB203580. It is concluded that the inhibition of NHE1 can inhibit IL-8 expression through up-regulation of p38 phosphorylation.
Cation Transport Proteins ; antagonists & inhibitors ; Down-Regulation ; Guanidines ; pharmacology ; Humans ; Imidazoles ; pharmacology ; Interleukin-8 ; metabolism ; K562 Cells ; Phosphorylation ; drug effects ; Pyridines ; pharmacology ; Sodium-Hydrogen Exchanger 1 ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; Sulfones ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo explore the effects of intrathecal injection of neuronal nitric oxide synthase (nNOS) inhibitors 7-Nitroindazole (7-Ni) and inducible nitric oxide synthase(iNOS) inhibitors aminoguanidine (AG) on the behavioral changes of morphine-induced dependent and withdrawal rats; the expression of Fos, nNOS and iNOS in spinal cord.

METHODSTo set up morphine dependence model, rats were subcutaneously injected with morphine (twice a day, for 5 d). The dose of morphine was 10 mg/kg in the first day and was increased by 10 mg/ kg every day. On day 6, 4 h after the injection of morphine (50 mg/kg), morphine withdrawal syndrome was precipitated by an injection of naloxone (4 mg/kg ip). 7-Ni, an nNOS inhibitor or iNOS inhibitors AG were intrathecally injected 30 min before the administration of naloxone respectively. The scores of morphine withdrawal symptom and morphine withdrawal-induced allodynia were observed. One hour after naloxone-precipitated withdrawal, Fos protein expression was assessed by immunohistochemical analysis and Western blot was used to detect the expression of nNOS and iNOS in the rat spinal cord.

RESULTSIntrathecal administration of nNOS inhibitor 7-Ni and iNOS inhibitors AG decreased the scores of morphine withdrawal, attenuated morphine withdrawal-induced allodynia and also inhibited the increase of Fos protein expression in the spinal cord of morphine withdrawal rats. nNOS and iNOS positive neurons in dorsal horn in nNOS group and iNOS group were significantly lower than that in withdrawal group. Compared with withdrawal group, level of nNOS and iNOS protein in spinal cord in nNOS group and iNOS group were significantly lower.

CONCLUSIONIt is suggested that nNOS and iNOS in the spinal cord may contribute to naloxone-precipitated withdrawal in rats and may play different roles in the above-mentioned effect.

Animals ; Guanidines ; pharmacology ; Indazoles ; pharmacology ; Male ; Morphine Dependence ; metabolism ; Naloxone ; pharmacology ; Nitric Oxide Synthase Type I ; antagonists & inhibitors ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; metabolism ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; drug effects ; metabolism ; Substance Withdrawal Syndrome ; metabolism

This experimental study was designed to explore the possible mechanisms of Cariporide, a kind of Na+/H+ exchanger inhibitor, for protecting the lung from warm ischemia/reperfusion injury (WI/RI) of isolated rat lung model. Thirty isolated rat lungs were established on the Langendorff apparatus and randomly divided to three groups (n = 10, each): control group (C group), ischemia/reperfusion group (IR group) and Cariporide group (CP group). Mean pulmonary artery pressure (MPAP) and peak airway pressure (pAwP) were monitored continuously. At the end of reperfusion, right bronchoalveolar lavage was performed, bronchoalveolar lavage fluid (BALF) recovery rate (BALFRR) was recorded, and protein content in BALF was measured. Lung water content (LWC), malondialdehyde (MDA) and superoxide dismutase (SOD)of left lung tissue were measured; histomorphology evaluation was performed under light microscope and transmission electron microscope. In comparison with the data from IR group, BALF protein concentration, LWC, MDA content and MPAP content of reperfusion were significantly decreased, but SOD activity was increased in CP group. Histomorphologic feature also showed that pathological change significantly reduced in CP group. In this rat WI/RI model, the mechanism by which the selective Na+/H+ exchanger inhibitor (Cariporide) attenuates lipid peroxidation induced by WI/IR may be: preventing Ca2+ overload via inhibiting the transport of Na+/H2 exchanger-1 (NHE1) in the context of the coupled exchanger, thereby reducing the activation of xanthine oxidase pathway and oxygen free radical liberation which is dependent on certain intracellular Ca2+ concentration, and lastly promoting the endogenous antioxidative mechanism.
Animals ; Antioxidants ; pharmacology ; Guanidines ; pharmacology ; In Vitro Techniques ; Ischemic Preconditioning ; Lung ; blood supply ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; etiology ; prevention & control ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; Sulfones ; pharmacology ; Superoxide Dismutase ; metabolism ; Warm Ischemia

Sodium/proton exchanger 1 (NHE1) plays an important role in the cardiomyocyte development. To study the effect of NHE1 activity in stem cells differentiation into cardiomyocytes, we treated P19 stem cells with dimethyl sulfoxide (DMSO) to initiate cardiomyocyte differentiation. In separate experiments, P19 cells were incubated with NHE1 specific inhibitor EMD87580 during the DMSO induction. The formed embryoid bodies (EBs) were detected with cell morphology detection, immunohistochemisty staining and RT-PCR analysis of expression of cardio-specific gene markers. Results showed that P19 cells were able to differentiate into cardiomyocytes and form the beating cell clusters. However, when cells treated with NHE1 inhibitor EMD87580, they could still form the EBs and proliferate when cell clusters adhered on the culture plate, but cells were unable to differentiate. This observation indicates that inhibition of NHE1 activity affected P19 stem cells differentiating into cardiomyocytes.
Animals ; Cation Transport Proteins ; antagonists & inhibitors ; Cell Differentiation ; drug effects ; Cell Line ; Culture Media ; Dimethyl Sulfoxide ; pharmacology ; Guanidines ; pharmacology ; Mice ; Myocytes, Cardiac ; cytology ; Sodium-Hydrogen Exchanger 1 ; Sodium-Hydrogen Exchangers ; antagonists & inhibitors ; Stem Cells ; cytology ; drug effects ; Sulfones ; pharmacology