title: The dissociation between the plasma levels of aminopeptidases A and B in spontaneously hypertensive rats.
abstract: We performed a longitudinal study for 20 weeks on spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR) to determine the relationship between peptide metabolism and the age-dependent increase in blood pressure. In both SHR and WKR, the plasma level of aminopeptidase A (AP-A) clearly showed an age-dependent decrease. The plasma level of aminopeptidase B paralleled that of AP-A in WKR, but such an age-dependency was not observed in SHR, thus showing a dissociation between the two aminopeptidases. With age in both strains, the level of angiotensin-converting enzyme tended to decrease, while that of kallikrein activity tended to increase. In addition to these findings, a multivariate study testing the relationship of blood pressure to these enzyme activities, as well as to plasma levels of angiotensin I and renin activity, suggested abnormalities in the networks of proteolytic enzymes and in the peptide metabolism surrounding the renin-angiotensin system in SHR. These abnormalities may play some important roles in pathophysiological mechanisms of hypertension in SHR.
mesh_terms: D000375:Aging / Q000502:physiology; D000626:Aminopeptidases / Q000097:blood*; D000803:Angiotensin I / Q000097:blood; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D043384:Glutamyl Aminopeptidase; D006973:Hypertension / Q000201:enzymology*; D008297:Male; D010447:Peptide Hydrolases / Q000097:blood; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood
chemical_list: D000803:Angiotensin I; D010447:Peptide Hydrolases; D000626:Aminopeptidases; C019721:aminopeptidase B; D043384:Glutamyl Aminopeptidase; D012083:Renin