Abstract
The antihypertensive effect of continuous oral administration of an alkaline protease hydrolysate (WPH) of whey protein isolate (Isolac, WPI) was compared with that of the WPI (control group) in spontaneously hypertensive rats (SHR). A suppressive effect on elevation of systolic blood pressure (SBP) in SHR was observed after oral administration of the WPH for two weeks. Mean SBPs at the end of 3 weeks of feeding were 193±3mmHg in the control group and 164±2mmHg in the WPH group (p<0.001). Organ weights of SHR fed WPH for 3 weeks were not significantly different from those in the control group. The serum total cholesterol level in SHR fed WPH was significantly (p<0.05) lower than that in the control group. The WPH used in the present experiment contained the angiotensin I converting enzyme (ACE)-inhibitory dipeptides, Val-Tyr, Phe-Leu, Ile-Leu and Val- Phe. Therefore, the antihypertensive effect may be attributable to these peptides contained in the WPH. These results suggest that the short chain peptides in WPH administered orally are absorbed from the intestinal tract and exert an antihypertensive effect.
