REDUCTION EFFECT OF THEANINE ON BLOOD-PRESSURE AND BRAIN 5-HYDROXYINDOLES IN SPONTANEOUSLY HYPERTENSIVE RATS

The effect of theanine, one of the components of green tea, on the blo od pressure and brain 5-hydroxyindoles in spontaneously hypertensive r ats (SHR) and Wistar Kyoto rats (WKY) was investigated by intraperiton eally administering theanine, The effect of glutamine, which is struct urally similar to theanine, was also examined, When SHR were injected with various amounts of theanine (0, 500, 1000, 1500, and 2000 mg/kg), the change was dose-dependent, and a significant decrease in blood pr essure was observed with the high doses (1500 and 2000 mg/kg), A dose of 2000 mg/kg of theanine did not alter the blood pressure of WKY, whi le the same dose to SHR decreased it significantly, On the other hand, glutamine administration to SHR did not change either the blood press ure or the heart rate, The brain 5-hydroxyindole level was significant ly decreased by theanine administration to both WKY and SHR, the decre ase being dose-dependent.