Abstract
The possible role of aldosterone in pinealectomy induced hypertension was studied by using daily spironolactone administration (10 mg/kg orally) from the second postoperative day. induced blood pressure elevation was Pinealectomy partly inhibited and the reduction of serum potassium concentration antagonized by spironolactone. The urine volume was increased but the excretion of sodium and potassium decreased in pinealectomized animals. These changes, too, were prevented by spironolactone administration. In spironolactone treated pinealectomized rats the sodium concentration was slightly increased in both the heart and the arterial wall. The ability of spironolactone to antagonize the pinealectomy induced hypertension and the changes in the electrolyte concentrations in plasma and urine supports our earlier suggestion of an increased aldosterone secretion in this type of hypertension in rats.