Adrenal alpha(2)-adrenergic receptors in the aging normotensive and spontaneously hypertensive rat

• Type: Article in International Scientific Journal
• Date: 2012

Authors

moura, e (Author) Other; pinto, ce (Author) Other; serrao, mp (Author) Other; afonso, j (Author) Other; vieira-coelho, ma (Author) FMUP

Journal

Title: Neurobiology of Aging

Vol. 33

Pages: 969-978

ISSN: 0197-4580

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 5 Citations

Scientific classification

FOS: Medical and Health sciences > Clinical medicine

Other information

Authenticus ID: P-002-AVN

DOI: 10.1016/j.neurobiolaging.2010.06.021

Abstract (EN): This study investigates alpha(2)-adrenergic receptor (alpha(2)AR) mediated feedback inhibition of catecholamine release from the adrenal medulla of adult (52 weeks) and old (98 weeks) spontaneously hypertensive rats (SHR) and normotensive controls Wistar Kyoto (WKY) rats. Adrenal epinephrine content as well as the spontaneous and the nicotinic-evoked release of epinephrine were similar between adult SHR and WKY rats. Aging produced a significant reduction in epinephrine synthesis in WKY rats. In contrast, in SHR aging produced a significant increase in epinephrine release without significant changes in epinephrine synthesis. The alpha(2)AR agonist medetomidine abolished (80-90% inhibition) the nicotinic-evoked release of epinephrine in adult SHR and WKY rats. With aging, this effect was unaltered in WKY rats but was significantly decreased in SHR (30% inhibition). Adrenal alpha(2A)AR mRNA levels were significantly reduced in old SHR compared with age matched WKY rats. In conclusion, in aging the alpha(2)AR mediated feedback inhibition of epinephrine release from the adrenal medulla is preserved in WKY rats but compromised in SHR, resulting in increased epinephrine release.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10