Hemodynamic changes following long-term administration of CS-905, a novel dihydropyridine calcium blocker, in conscious SHR.

To investigate the central and regional hemodynamics after long-term administration of CS-905, a novel calcium blocker, we administered the agent (1 and 3 mg/kg/day) for 15 weeks in spontaneously hypertensive rats. At the end of the dosing period, hemodynamic changes were examined using the radioactive microsphere technique. CS-905 produced a sustained dose-dependent antihypertensive effect without inducing tolerance during the 15-week dosing period and prevented cardiac hypertrophy. The agent increased cardiac output, decreased blood pressure and thus decreased total peripheral resistance in a dose-related manner. Regional blood flows measured by the microsphere technique were increased in the kidney and brain despite the lowered blood pressure. There was no organ where regional blood flow was decreased. These changes after chronic treatment with CS-905 would be beneficial in the long-term therapy of hypertension.