Oral administration of peptides derived from bonito bowels decreases blood pressure in spontaneously hypertensive rats by inhibiting angiotensin converting enzyme

Comp Biochem Physiol C Comp Pharmacol Toxicol. 1993 Feb;104(2):351-3.


1. Peptides C111 (Gly-Val-Tyr-Pro-His-Lys) and C112 (Ile-Arg-Pro-Val-Gln), extracted from the autolysis product of bonito liver and intestine, have been shown to inhibit angiotensin converting enzyme (ACE) activity in vitro with IC50s of 1.6 microM and 1.4 microM, respectively. We examined the effects of oral administration of these peptides on blood pressure. 2. Oral administration of these peptides (500 mg kg-1 body weight each) inhibited the pressor effect of intravenously administered angiotensin I in Sprague-Dawley rats. 3. In spontaneously hypertensive rats, oral administration of these peptides (100-200 mg kg-1 body weight) showed depressor effects. 4. These results suggest that the peptides, C111 and C112, are orally effective ACE inhibitors with hypotensive effect.

MeSH terms

  • Administration, Oral
  • Amino Acid Sequence
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology*
  • Animals
  • Blood Pressure / drug effects*
  • Fishes / metabolism*
  • Hypertension / drug therapy*
  • Male
  • Molecular Sequence Data
  • Peptides / pharmacology*
  • Rats
  • Rats, Inbred SHR
  • Rats, Sprague-Dawley


  • Angiotensin-Converting Enzyme Inhibitors
  • Peptides