ABSTRACT
AIM To study the effects of protein tyrosine kinase inhibitor and protein tyrosine phosphatase inhibitor on cultured bovine cerebrovascular smooth muscle cells (CSMC) Ca 2+ store operated Ca 2+ influx. METHODS Cell culture and single intracellular free Ca 2+ concentration was measured in fura 2/Am flueorescence probe by MetaFluor Fluorescence ratio imaging system. RESULTS (1) protein tyrosine kinase inhibitor (genistein,2.5,5,10 ?mol?L -1 )decreased Ca 2+ influx significantly induced by endothelin 1(ET 1),ATP,cyclopiazonic acid(CPA) in concentration dependent manner; (2) Protein tyrosine phosphatase inhibitor (vanadate,2,4,8 ?mol?L -1 ) increased Ca 2+ influx significantly induced by ET 1,ATP,CPA in concentration dependent manner. CONCLUSION Protein tyrosine kinase inhibitor and protein tyrosine phosphatase inhibitor have effects on Ca 2+ store operated Ca 2+ influx induced by ET 1, ATP, CPA. Protein tyrosine phosphorylation participats in the signal transduction of Ca 2+ store operat Ca 2+ influx in cerebrovascular smooth muscle cells.
ABSTRACT
AIM To study the effects of different kinds of chloride channel blockers on KCl and 5 HT induced contractile responses in cerebrovascular smooth muscle. METHOD The tension of rabbit basilar artery rings was measured. RESULTS ① DIDS, furosemide and NPPB inhibited the responses to KCl and 5 HT in a concentration dependent manner. The effects of DIDS, furosemide and NPPB on the response to 5 HT were stronger than that to KCl. ②When SK&F 96365 evoked a maximum inhibitory effect on 5 HT induced response, subsequent additions of DIDS, furosemide and NPPB could further produced vascular relaxation. CONCLUSION The chloride channel participates KCl and 5 HT induced contractile responses in cerebral basilar artery.