Amiloride analogs stimulate protein phosphorylation and serotonin release in human platelets.
We examined the effects of newly exploited amiloride analogs on protein phosphorylation and serotonin secretion in human platelets. 5-(N-methyl-N-isobutyl) amiloride (IBA) and, to a lesser extent, 5-(N-methyl-N-isopropyl) amiloride (IPA), highly specific inhibitors of Na+/H+-pump, induced the phosphorylation of 47K-dalton protein and myosin light chain (20K). The phosphorylation was inhibited by apyrase. On the other hand, 3', 4'-dichlorobenzamil (DCB) and 2', 4'-dimethylbenzamil (DMB), highly specific inhibitors of Na+/Ca2+-pump, and to a lesser extent amiloride analogs induced serotonin secretion. Apparently there was dissociation between the phosphorylation and the serotonin release induced by the analogs.
Department of Legal Medicine, Osaka University, Medical School, Japan.
K
K
Yoshida
E J
EJ
Cragoe
D000584:Amiloride / Q000031:analogs & derivatives* / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D010766:Phosphorylation; D012701:Serotonin / Q000097:blood*
D001798:Blood Proteins; D012701:Serotonin; D000584:Amiloride