PREINCUBATION OF THYMOCYTES WITH 1-(5-ISOQUINOLINESULFONYL)-2-METHYLPIPERAZINE DIHYDROCHLORIDE (H-7) INDUCES APOPTOSIS IN NON-STIMULATED THYMOCYTES

1-(5-Isoquinolinesulfonyl)-2-methylpiperazine hydrochloride (H-7), an inhibitor of protein kinases, has been shown to inhibit the thymocyte apoptosis induced by various apoptogenic agents. In the present study, when mouse thymocytes were pretreated with H-7, washed, and cultured for an additional time, apoptosis was induced depending on the preincu bation time and the dose of H-7. The protein kinase C activity in the H-7-pretreated and -washed cells was not altered, suggesting that an a lteration of a certain PKC isoform is related to both the triggering a nd the progression of apoptosis.