Document Detail


Adrenomedullin relaxes rat uterine artery: mechanisms and influence of pregnancy and estradiol.
MedLine Citation:
PMID:  20631002     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Uterine arteries play a major role in regulating uteroplacental blood flow. Failure to maintain blood flow to the uteroplacental compartment during pregnancy often results in intrauterine growth retardation. Immunohistochemical staining of adrenomedullin (AM), an endogenous vasoactive peptide, in uterine artery was intense in pregnant compared to nonpregnant rats, but it is not known whether AM directly relaxes uterine artery or not. In this study, we elucidated the mechanisms of uterine artery relaxation by AM and its regulation by pregnancy and female sex steroids. AM was able to relax uterine artery, and this relaxation was influenced positively by pregnancy and estradiol as evidenced by the increased pD(2) and E(max) values of AM. Both pregnancy and estradiol treatment to ovariectomized rats amplified RAMP(3) expression in uterine arteries while progesterone had no effect. AM-induced uterine artery relaxation is predominantly endothelium-dependent. The AM receptor antagonist CGRP(8-37) is more potent than AM(22-52) in inhibiting the AM relaxation, indicating the involvement of AM(2) receptor subtype. Moreover, AM uses the classical nitric oxide-cyclic guanosine monophosphate pathway along with K(Ca) channels to mediate the vasodilatory effect in uterine artery. In conclusion, sensitivity of uterine artery to AM-induced relaxation is increased with pregnancy or estradiol treatment by increasing RAMP(3) expression, suggesting an important role for AM in regulating the uterine hemodynamics, probably maintaining uterine blood flow during pregnancy and in pre- and postmenopausal cardiovascular adaptation differences.
Authors:
Gracious R Ross; Uma Yallampalli; Pandu R R Gangula; Luckey Reed; K Sathishkumar; Haijun Gao; Madhu Chauhan; Chandra Yallampalli
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, N.I.H., Extramural     Date:  2010-07-14
Journal Detail:
Title:  Endocrinology     Volume:  151     ISSN:  1945-7170     ISO Abbreviation:  Endocrinology     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-08-25     Completed Date:  2010-10-04     Revised Date:  2011-09-13    
Medline Journal Info:
Nlm Unique ID:  0375040     Medline TA:  Endocrinology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  4485-93     Citation Subset:  AIM; IM    
Affiliation:
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
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MeSH Terms
Descriptor/Qualifier:
Adrenomedullin / chemistry,  pharmacology*
Animals
Calcitonin Gene-Related Peptide / pharmacology
Dose-Response Relationship, Drug
Endothelium, Vascular / physiology
Estradiol / pharmacology*
Female
Gene Expression / drug effects
Glyburide / pharmacology
Intracellular Signaling Peptides and Proteins / genetics
Membrane Proteins / genetics
Ovariectomy
Peptide Fragments / pharmacology
Potassium Channel Blockers / pharmacology
Pregnancy
Progesterone / pharmacology
Rats
Rats, Sprague-Dawley
Receptor Activity-Modifying Proteins
Reverse Transcriptase Polymerase Chain Reaction
Uterine Artery / drug effects*,  metabolism,  physiology
Vasodilation / drug effects*
Vasodilator Agents / pharmacology
Grant Support
ID/Acronym/Agency:
HL-58144/HL/NHLBI NIH HHS; HL-72620/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Intracellular Signaling Peptides and Proteins; 0/Membrane Proteins; 0/Peptide Fragments; 0/Potassium Channel Blockers; 0/Receptor Activity-Modifying Proteins; 0/Vasodilator Agents; 10238-21-8/Glyburide; 119911-68-1/calcitonin gene-related peptide (8-37); 148498-78-6/Adrenomedullin; 50-28-2/Estradiol; 57-83-0/Progesterone; 83652-28-2/Calcitonin Gene-Related Peptide
Comments/Corrections

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