Antihypertensive effect of ACE inhibitory oligopeptides from chicken egg yolks

Oligopeptides of 1 KDa or less were obtained by hydrolysis of chicken egg y olks with a crude enzyme, and by dialysis with a semipermeable membrane fil ter. Since the extracted peptides had an inhibitory action on the activity of angiotensin I-converting enzyme (ACE) in vitro, they were orally adminis tered at 20, 100 and 500 mg/kg body weight to spontaneously hypertensive ra ts (SHR) for 12 weeks to analyze the physiological role on cardiovascular f unctions. The administered oligopeptides suppressed the development of hype rtension at all dosages. After 12 weeks at 500 mg/kg body weight, the value s for systolic, mean, and diastolic blood pressure were approximately 10% l ess in SHRs administered than controls. Furthermore, serum ACE activity of the peptide-administered groups was significantly lower than that of the co ntrol group in a dose-related manner. Our results imply that oligopeptides extracted from hen's egg yolks could potentially suppress the development o f hypertension in SHR, and this effect might be induced by the inhibition o f ACE activity. (C) 2001 Elsevier Science Inc. All rights reserved.