首页 | 本学科首页   官方微博 | 高级检索  
     


Effects of histamine on inositol phosphates and intracellular Ca2+ in human glomerular epithelial cells
Authors:Spath, M. M.   Pavensradt, H.   Fischer, R.   Schlunck, G.   Wanner, C.   Schollmeyer, P.
Affiliation:Medizinische Universitätsklinik, Abteilung Innere Medizin IV Freiburg, Germany
Abstract:The effect of histamine on the phosphoinositide turnover andintracellular free calcium activity [Ca2+]i was examined inhuman glomerular epithelial cells in culture. Addition of histamineto glomerular epithelial cells resulted in formation of inositolphosphates in a time- and dose-dependent manner. A transientmaximum of inositol trisphosphate (InsP3) was observed within10 s. Stimulation of protein kinase C by short-term pretreatment(15 mm) of glom erular epithelial cells with phorbol 12-mynstate13-acetate caused a dose-dependent inhibition of the histamine-inducedinositol phosphate accumulation. The baseline of [Ca2+]i inthe cells was 115 ±2.7 nmol/l (n=103). Histamine (ED50:approx. 2x10–7mol/l) caused a rapid and transient increasein [Ca2+]i, as detected by fura-2 microfluorimetry studies.In a calcium-free extracellular solution the rapid increaseof [Ca2+]i was still present. The H1 receptor antagonist mepyramine(IC50: approx. 8 x 10–9 mol/l) inhibited the histamine(10–6 mol/l) response on [Ca2+]i Cimetidine, a potentH2 receptor antagonist, showed no effect. This data indicates that H1 receptor activation causes hydrolysisof phosphatidylinositol 4, 5-bisphosphate by phospholipase Cactivation, and consecutive mobil ization of intracellular calcium.Since histamine is a mediator of inflammation, antigen responseand cellular injury, these findings could be of importance forthe understanding of glomerular epithelial cell pathology.
Keywords:cimetidine   fura-2   glomerulus   H1 receptor   mepyramine   phospholipase C
本文献已被 Oxford 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号