[Cicletanine and the sympathetic nervous system. A study of awake sino-aortic denervated hypertensive dogs]

Abstract

The antihypertensive action of non diuretic doses of cicletanine, a new antihypertensive compound, has been studied in neurogenic hypertensive dogs. Four months after sinoaortic denervation, Fourteen dogs were randomly allocated into two parallel groups of oral treatment: cicletanine (10 mg/kg/12 h (n = 7)) or placebo (n = 7). Urinary parameters (diuresis, urinary sodium, potassium, urea and creatinine clearance), cardiovascular parameters (blood pressure (BP) and heart rate) and sympathetic tone (noradrenaline and adrenaline plasma levels) were measured before and after one month of treatment in conscious animals. Chronic treatment with cicletanine lowered BP in neurogenic hypertensive dogs (204 +/- 10/116 +/- 5 mmHg before and 159 +/- 12/86 +/- 8 mmHg after treatment) without any diuretic effect. Cicletanine failed to modify plasma noradrenaline (457 +/- 100 pg/ml versus 419 +/- 135 pg/ml) or adrenaline (213 +/- 36 pg/ml versus 166 +/- 35 pg/ml). These data confirm that cicletanine exerts antihypertensive actions which are independent of its natriuretic properties. Moreover, they suggest that the decrease in arterial blood pressure does not involve sympathetic pathways.