Chopra L C, Twort C H, Ward J P, Cameron I R
Department of Medicine, U.M.D.S., St Thomas' Hospital, London, UK.
Biochem Biophys Res Commun. 1989 Aug 30;163(1):262-8. doi: 10.1016/0006-291x(89)92130-x.
The effects of heparin on intracellular calcium release in monolayers of permeabilised cultured rabbit smooth muscle cells were determined using 45Ca effluxes. Low molecular weight heparin inhibited inositol 1,4,5-trisphosphate (InsP3) induced Ca2+ release (IC50 = 0.8 microgram/ml), but not guanosine 5'-O-(3-thio triphosphate) (GTP gamma S) stimulated Ca2+ release. Only a small inhibition was noted with high molecular weight heparin and de-N-sulphated heparin, although chondroitin sulphate A potently inhibited the InsP3 response. These results indicate the competitive and specific nature of the heparin effect and give information about the structure of the InsP3 site.
利用45Ca外流测定了肝素对通透的培养兔平滑肌细胞单层中细胞内钙释放的影响。低分子量肝素抑制肌醇1,4,5-三磷酸（InsP3）诱导的Ca2+释放（IC50 = 0.8微克/毫升），但不抑制鸟苷5'-O-(3-硫代三磷酸)（GTPγS）刺激的Ca2+释放。高分子量肝素和去N-硫酸化肝素仅有轻微抑制作用，而硫酸软骨素A能有效抑制InsP3反应。这些结果表明了肝素作用的竞争性和特异性，并提供了有关InsP3位点结构的信息。
