ABSTRACT
Objective: To study the effect of lipopolysaccharides(LPS) on nitric oxide(NO) production in synoviocytes and inhibition of genistein on it.Methods: LPS or LPS+genistein stimulated synoviocytes in vitro .NO in culture medium was determined by Griess method.Results: LPS dose and time dependently induced NO production in synoviocytes; Genistein (6.25 50 ?mol/L) dose dependently inhibited the production of NO induced by lipopolysaccharide.Conclusion:The effect of LPS on NO production can be dose dependently inhibited by genistein,this may be mediated by tyrosine kinase(PTK).
ABSTRACT
Objective: To study the effects of herbimycin A on proliferation and NO production stimulated by IL 1 in chondrocytes. Methods: IL 1 alone or in combination with herbimycin A was administered.Chondrocytes proliferation was detected by crystal violet dying method and NO production was detected by Griess method. Results: IL 1 inhibited chondrocytes proliferation. Herbimycin A dose dependently reversed the effect. Also herbimycin A could inhibit NO production induced by IL 1. Conclusion: The reversing effect of herbimycin A on chondrocytes proliferation may be mediated by NO.
ABSTRACT
The effects of protein kinase C (PKC) inhibitors 1- (5-isoquinolinylsulfonyl) - 2-methylpoperazine (H-7) and quercetin on endotheliai-polymorphoneuclear (EC-PMN) adhesion induced by tumor necrosis factor (TNF) and platelet activating factor (PAF) were studied in cultured bovine pulmonary artery endothelial monolayers in vitro. TNF (100 U/ml) and PAF (1.0 ?mol/L) stimulated EC dependent PMN-EC adhesion. Both H-7 and quercetin dose-dependently inhibited TNF and PAF induced PMN-EC adhesion. The IC50 of H-7 was 22.22, 5.25 umol/L, and that of quercetin was 18.30, 4.83 ?mol/L respectively. WEB-2086, a specific PAF receptor antagonist, dose-dependently inhibited PAF induced PMN-EC adhesion, but had no effect on TNF induced adhesion. These results suggest that PKC play an important role in EC activation by TNF or PAF, and TNF induced PMN-EC adhesion by independent on endogenetic PAF.