Related Experiment Video
Updated: Sep 28, 2026

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
Published on: July 14, 2016
Effects of age, hypertension and HRT on serum aminopeptidase A activity
Mari Ijima1, Seiji Nomura, Mayumi Okada
1Department of Obstetrics and Gynecology, Nagoya University School of Medicine, 466-8550, Nagoya, Japan.
Objectives:
It is conceivable that aminopeptidase A (APA)/angiotensinase is involved in the pathogenesis of hypertension. The aim of this study was to evaluate the influences of age, hypertension and hormone replacement therapy (HRT) on serum APA activity in middle-aged and elderly women.
Methods:
Blood samples were collected from 117 women aged 40-69, 48 normotensive healthy women not receiving HRT, 57 normotensive women receiving HRT, and 12 hypertensive women (blood pressure >140/90 mmHg) with no medication. Serum APA activity was measured using alpha-glutamyl-p-nitroanilide as substrate spectrophotometrically.
Results:
Serum APA activity increased along with age between 40 and 69 in healthy women not taking HRT (r=0.351, P<0.05). Hypertensive women had higher serum APA activity than age-matched normotensive women (25.4+/-4.2 versus 22.4+/-3.4 microM/min; P<0.05) Compared with non-users of HRT, APA activity was elevated in women receiving HRT (23.9+/-3.8 versus 20.4+/-3.2 microM/min; P<0.05).
Conclusions:
APA activity had a positive correlation with age in healthy women. Furthermore, hypertension and HRT up-regulated the serum APA activity significantly. The measurements of serum APA would be of value to elucidate the physiological and clinical roles of APA, although further studies are required.
Related Concept Videos
Antihypertensive Drugs: Angiotensin-Converting Enzyme Inhibitors
Pharmacodynamics in Geriatric Patients: Effects of Age
Antihypertensive Drugs: Direct Renin Inhibitors
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System
Blood Studies for Cardiovascular System II: CRP, Hcy, and Cardiac Natriuretic Peptide Markers
These markers indicate stress or strain on the heart muscle:
Natriuretic Peptides (BNP)
Cardiac myocytes produce these hormones in response to ventricular stretching...
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...