摘要：Six week-old male spontaneously hypertensive rats (SHR) were orally administered a decaffeinated hot-water extract from green tea at dose levels of 2 and 10g/kg/day for 4 weeks. RNA (previously reported as a hypotensive component of green tea) and 2′(3′)-AMP (as an active constituent of RNA) were also examined, comparing with respect to the function of the decaffeinated hot-water extract. In the decaffeinated hot-water extract group, a dose-dependent suppression of hypertension development was observed. The systolic blood pressure was about 15mmHg lower in the higher dose group than in the control group at 2 week-period of administration and thereafter. The antihypertensive effect on the RNA group (250mg RNA/kg/day) was similar to that on the higher dose group. Essentially the same was observed in the 2′(3′)-AMP group (65mgAMP/kg/day) only at about 2 week-period of administration. Serum urea nitrogen was decreased in proportion to the dose of the decaffeinated hot-water extract. There was no significant difference among the groups in body weight, organ weight, other serum biochmical parameters, and cyclic-AMP concentration in plasma and aorta.
