Age-related changes in dorsal root ganglia, circulating and vascular calcitonin gene-related peptide (CGRP) concentrations in female rats: Effect of female sex steroid hormones

NEUROSCIENCE LETTERS

卷:454

Article

Gangula, Pandu R. R.¹  Chauhan, Madhu²  Reed, Luckey²  Yallampalli, Chandra² 

[1] Meharry Med Coll, Dept Obstet & Gynecol, Nashville, TN 37208 USA

[2] Univ Texas Galveston, Med Branch, Dept Obstet & Gynecol, Galveston, TX 77550 USA

关键词: Dorsal root ganglia;    Young adult;    Aging;    CGRP;    Estrogen;    Progesterone;    Circulation;    Vasculature;   

DOI  :  10.1016/j.neulet.2009.02.068

来源: Elsevier

【 摘 要 】

The aim of the present study is to investigate whether immunoreactive (1) calcitonin gene-related peptide (CGRP) content is decreased in plasma and mesenteric arteries (resistance arteries) in middle-aged rats and if so, whether sex steroid hormones enhance I-CGRP in middle-aged female rats. We also examined whether vascular CGRP receptor components, calcitonin receptor like receptor (CRLR) and receptor activity modifying protein 1 (RAMP(1)) are elevated by sex steroid hormones treatment in middle-aged female rats. Young adult (3 months old) and middle-aged (10-12 months old) ovariectomized rats were treated subcutaneously with estradiol-17 beta (E-2; 2 mg), progesterone (P-4; 5 mg), E-2 + P-4 (2 mg + 20 mg) or placebo (control). Radioimmunoassay and Western blot analysis were performed to measure I-CGRP content and CGRP receptor components in dorsal root ganglia (DRG), in resistance arteries and in plasma. Immunofluorescent staining methods were employed to determine cellular localization of CRLR, RAMP(1) in resistance arteries. Our data demonstrated that I-CGRP content was significantly (p<0.05) lower in the plasma and resistance arteries of middle-aged female rats compared to young controls. Both RAMP(1) and CRLR were concentrated in vascular endothelium and the underlying smooth muscle cells. RAMP(1) but not CRLR appeared to be decreased in middle-aged rat vasculature. Chronic perfusion of sex steroid hormones to ovariectomized rats: (1) significantly (p<0.05) elevated I-CGRP in the DRG and in the plasma, and (2) significantly elevated RAMP(1) (p<0.05) but did not alter CRLR in resistance arteries. These data suggest that female sex steroid treatment enhances I-CGRP and its receptors, and thus regulate the blood pressure in aged female rats. Published by Elsevier Ireland Ltd.

【 授权许可】

Free