[Clinical and experimental study of clofelin pharmacodynamics].

Hemodynamic mechanisms of clophelin hypotensive effect were studied in 122 patients with arterial hypertension. In most cases, antihypertensive clophelin therapy did not affect the nature or magnitude of orthostatic and stress-induced hemodynamic shifts. The fact that the fall in perfusion BP was not accompanied with a resting, orthostatic or stress-induced impairment of renal function was a particularly valuable aspect of clophelin treatment. Experimental studies demonstrated that clophelin hypotensive effect was partly due to limited Ca2+ entrance through the slow calcium channels in the cell membrane as well as limited potassium withdrawal during excitation. Single and repeated clophelin administration (0.03-1 mg/kg daily) was shown to depress reproductive capacity in rats of both sexes, due to suppressed blood levels of pituitary gonadotrophin as well as altered gonadal sensitivity to gonadotrophin effects.