Effect of 10-hydroxycamptothecin on adenylate cyclase activity in murine hepatoma cells
Abstract
10-Hydroxycamptothecin is a new antitumor principle isolated from indigenous to China. It has been found in our laboratory that 10-hydroxycamptothecin raised cAMP levels in murine hepatoma cells. Whether such action is related to activation of adenylate cyclase system was investigated.
The activity of adenylate cyclase was not changed markedly in vitro by 10-hydroxycamptothecin 1 μM-5 mM. In vivo, ip 10-hydroxycamptothecin 10 mg/kg qd×3 d elevated significantly the intracellular cAMP level and adenylate cyclase activity by 67% and 82%, respectively.
For control experiments the effect of dopamine on adenylate cyclase activity in hepatoma cells was observed. The results showed that dopamine strongly stimulated adenylate cyclase activity both in vitro and in vivo.
Keywords:
The activity of adenylate cyclase was not changed markedly in vitro by 10-hydroxycamptothecin 1 μM-5 mM. In vivo, ip 10-hydroxycamptothecin 10 mg/kg qd×3 d elevated significantly the intracellular cAMP level and adenylate cyclase activity by 67% and 82%, respectively.
For control experiments the effect of dopamine on adenylate cyclase activity in hepatoma cells was observed. The results showed that dopamine strongly stimulated adenylate cyclase activity both in vitro and in vivo.