A forskolin derivative, colforsin daropate hydrochloride, inhibits rat mesangial cell mitogenesis via the cyclic AMP pathway

A forskolin derivative, colforsin daropate hydrochloride (CDH), has been introduced as an inotropic agent that acts directly on adenylate cyclase to increase intracellular cyclic AMP (cAMP) levels and ventricular contractility, resulting in positive inotropic activity. We investigated the effects of CDH on rat mesangial cell (MC) proliferation. CDH (10–7–10–5 mol/l) inhibited [3H]thymidine incorporation into cultured rat MCs in a concentration-dependent manner. CDH (10–7–10–5 mol/l) also decreased cell numbers in a similar manner, and stimulated cAMP accumulation in MCs in a concentration-dependent manner. A protein kinase A inhibitor, H-89, abolished the inhibitory effects of CDH on MC mitogenesis. These findings suggest that CDH would inhibit the proliferation of rat MCs via the cAMP pathway.