Effect of gamma-aminobutyric acid (GABA) on normotensive or hypertensive rats and men.

Abstract

1. The effect of GABA on blood pressure of normotensive and hypertensive rats or men was investigated.2. GABA, when administered orally one g per day for a month, did not cause any appreciable changes in body weight, blood pressure and other side effects in normotensive rats. No histological changes were found in their organs.3. On the contrary, GABA reduced the elevated blood pressure of experimental renal hypertensive rats at the doses of more than thirty mg per day. Its effect was maintained during the application, and disappeared within one week after the interruption of treatment.4. When glutamate or aspartic acid of 50 mg per day was orally applied for three weeks, no change was observed in blood pressure of hypertensive rats.5. GABA, administered subcutaneously was also more effective in hypertensive rats than in normotensive ones.6. Subcutaneous injections of GABA (1-3 mg per kg) on normotensive subjects produced slight uncomfortable side effects.7. GABA, if administered orally three g per day, did not cause any appreciable effects on normotensive persons, but it lowered remarkably the elevated blood pressure of patients.