The inositol phosphate response to thrombin in rat right atria differs from the response to noradrenaline.
Addition of thrombin to isolated [3H]inositol-labelled rat right atria stimulated the release of 3H-labelled inositol phosphates. The thrombin response was smaller than the response to noradrenaline and generated a different spectrum of inositol phosphates. Unlike the inositol phosphate response to noradrenaline, the thrombin response was inhibited by pertussis toxin treatment and by the phospholipase C inhibitor U-73122 (1-(6-((17 beta-3- methoxyestra-1,3,5(10)-trien-17-yl)amino)amino)hexyl)-1H- pyrrole-2, 5-dione). The data indicate that the thrombin stimulation involves different G-proteins and phospholipase C isoforms from those which couple alpha 1-adrenoceptors in the myocardium.
Woodcock
E A
EA
Cellular Biochemistry Laboratory, Baker Medical Research Institute, Prahran (Melbourne) Victoria, Australia.
Lambert
K A
KA
D000818:Animals; D006325:Heart Atria / Q000187:drug effects*; D007295:Inositol Phosphates / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology*; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013917:Thrombin / Q000494:pharmacology*; D013997:Time Factors
D007295:Inositol Phosphates; D013917:Thrombin; D009638:Norepinephrine