this apparent desensitization may be due to a feedback regulation by protein kinase c , since pretreatment with the phorbol ester 12-o-tetradecanoyl phorbol 13-acetate ( tpa ) markedly inhibits ( by up to 70 % ) subsequent thrombin-induced inositol phosphate formation .
C0031586
phorbol ester
C0039654
phorbol