Antihypertensive effect of angiotensin I-converting enzyme inhibitory peptides derived from hemoglobin.
From proteolytic digest of swine hemoglobin, we isolated four peptide, E-1 (Phe-Gln-Lys-Val-Val-Ala), E-2 (Phe-Gln-Lys-Val-Val-Ala-Gly), peptide 30-3 (Phe-Gln-Lys-Val-Val-Ala-Lys) and H-1 (Gly-Lys-Lys-Val-Leu-Gln). These peptides inhibited angiotensin I-converting enzyme activity with an IC50 of 5.8, 7.4, 2.1 and 1.9 microM, respectively. Oral administration of 50 mg/kg E-1 and 50 mg/kg H-1 decreased blood pressure in spontaneously hypertensive rats. In normotensive rats, oral administration of 500 mg/kg E-1 and 500 mg/kg H-1 inhibited the pressor effect of i.v. administrated 300 ng/kg angiotensin I, possibly by inhibiting its conversion to angiotensin II. These results suggest that these peptides are orally effective inhibitors of angiotensin I-converting enzyme that have a hypotensive effect.
Mito
K
K
Foods Research Group, Asahi Chemical Industry Co. Ltd., Shizuoka, Japan.
Fujii
M
M
Kuwahara
M
M
Matsumura
N
N
Shimizu
T
T
Sugano
S
S
Karaki
H
H
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology; D006454:Hemoglobins / Q000737:chemistry*; D008297:Male; D009842:Oligopeptides / Q000302:isolation & purification / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D006454:Hemoglobins; D009842:Oligopeptides; D010446:Peptide Fragments; D002216:Captopril