Defects of thrombin-induced protein phosphorylation in platelets from stroke-prone spontaneously hypertensive rats.
Aggregation and secretion of washed platelets from stroke-prone spontaneously hypertensive rats (SHRSP) were greatly reduced by the development of the hypertension compared with those of platelets from age-matched normotensive Wistar-Kyoto rats (WKY). Concomitantly, thrombin-induced phosphorylation of the 47 kDa protein in SHRSP platelets was significantly decreased. However, TPA-induced aggregation, secretion and 47 kDa protein phosphorylation in SHRSP platelets were similar to those in WKY platelets. These results suggest that protein kinase C activity and its substrate were normally present in SHRSP platelets and that defects in the receptor-mediated activation of protein kinase C. This defective protein phosphorylation may be an underlying mechanism for the dysfunction of SHRSP platelets.
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D010766:Phosphorylation; D010974:Platelet Aggregation; D011493:Protein Kinase C / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012701:Serotonin / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013917:Thrombin / Q000378:metabolism*
D011506:Proteins; D012701:Serotonin; D011493:Protein Kinase C; D013917:Thrombin; D013755:Tetradecanoylphorbol Acetate