gamma-aminobutyric acid (GABA)-rich Chlorella depresses the elevation of blood pressure in spontaneously hypertensive rats (SHR)

Chlorella vulgaris CK-22 accumulated 542 mg% of glutamic acid in the cells when ammonium was added to the medium after heterotrophic culture. The glut amic acid-rich Chlorella cells produced 334 mg% of gamma-aminobutyric acid (GABA) after 1 hr of incubations at 38 degrees C pH 4.0 under anaerobic con dition. Next we examined the effects of GABA-rich Chlorella on blood pressu re in spontaneously hypertensive rats (SHR). Elevation of blood pressure in SHR was significantly depressed by 22 mmHg in the GABA-rich Chlorella grou p compared with the basal group. The results of blood analysis showed that serum triglyceride (TG) and blood urea nitrogen (BUN) levels were significa ntly lower in SHR fed the GABA-rich Chlorella diet compared with those fed the basal diet. The free cystein contents of liver were also higher in SHR fed the GABA-rich Chlorella diet compared with those fed the basal diet. Th ese results suggest that the GABA-rich Chlorella promotes the metabolism of amion acids containing sulfur and showed the hypotensive effect multiplica tively by GABA and/or amino acids containing sulfur.