Chronic treatment with naftidrofuryl attenuates the development of vascular hypersensitivity to serotonin in the spontaneously hypertensive rat.

Three-month-old spontaneously hypertensive rats were treated for 1, 2, or 3 months with daily intraperitoneal injections of naftidrofuryl (30 mg/kg). Systolic arterial pressure was measured. Tail arteries were removed and perfused at a constant flow rate of 2 ml/min. A concentration-response curve for serotonin was prepared. A second curve was then constructed in the presence of naftidrofuryl. Chronic treatment with naftidrofuryl had no effect on blood pressure but produced a decrease in the maximal vasoconstrictor response and the sensitivity to serotonin in vitro. The in vitro sensitivity to naftidrofuryl was unchanged. These studies suggest that chronic treatment with a dose of naftidrofuryl that does not modify blood pressure attenuates the in vitro vascular sensitivity to serotonin.