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Intermittent parathyroid hormone administration attenuates endothelial dysfunction in old rats
John J Guers1, Rhonda D Prisby1, David G Edwards1
1Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|November 6, 2016
Summary
Intermittent parathyroid hormone (PTH) administration improved aortic endothelial function in aged rodents by enhancing endothelial nitric oxide synthase (eNOS) expression. This suggests PTH may mitigate age-related vascular dysfunction.
Area of Science:
- Cardiovascular Science
- Aging Research
- Endocrinology
Background:
- Aging is a primary risk factor for cardiovascular disease, often marked by reduced endothelial function.
- Endothelial nitric oxide synthase (eNOS) expression and activity are critical for vascular health and decline with age.
Purpose of the Study:
- To investigate the impact of intermittent parathyroid hormone (PTH) administration on aortic endothelial function in aged rodents.
- To determine if PTH can reverse age-related declines in vascular function.
Main Methods:
- Old (24-month) and young (4-month) Fischer-344 rats received PTH 1-34 or placebo injections over 15 days.
- Aortic ring relaxation responses to acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) were measured.
- Aortic eNOS protein expression was quantified.
Main Results:
- Endothelium-dependent relaxation was significantly impaired in old control rats compared to young controls.
- PTH treatment improved endothelium-dependent relaxation (both AUC and Emax) in aged rats.
- PTH administration restored reduced aortic eNOS protein expression in aged rats.
Conclusions:
- Intermittent PTH administration effectively improves age-related endothelial dysfunction in rat aortas.
- PTH treatment normalizes eNOS expression, suggesting a mechanism for its vascular benefits.
- PTH represents a potential therapeutic strategy for combating age-related cardiovascular decline.
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