Document Detail


Enhanced depressor effect of bromocriptine in the DOCA/NaCl hypertensive rat.
MedLine Citation:
PMID:  2861750     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To elucidate the role of the dopaminergic system in the maintenance of hypertension in the deoxycorticosterone acetate (DOCA)/NaCl hypertensive rat, the responses of mean arterial pressure (MAP), plasma norepinephrine (NE), epinephrine (E), and prolactin (PRL) to intravenous (iv) administration of bromocriptine, a dopamine agonist, and hexamethonium bromide, a ganglion blocker, were examined in conscious, unrestrained 4-wk DOCA/NaCl hypertensive rats. Bromocriptine was administered to adrenomedullectomized (ADMX) rats to assess the role of the adrenal medulla in its depressor effect. Bromocriptine (50, 250, and 500 micrograms/kg) and hexamethonium (3 and 30 mg/kg) caused dose-dependent decreases in MAP that were greater in DOCA/NaCl rats than in uninephrectomized controls. Basal plasma NE, E, and PRL were significantly higher in DOCA/NaCl rats than in controls. Bromocriptine (500 micrograms/kg iv) decreased plasma PRL to undetectable levels and increased plasma E significantly without changing NE levels in DOCA/NaCl and uninephrectomized control rats. In ADMX rats bromocriptine (500 micrograms/kg iv) decreased MAP, PRL, and NE without affecting E levels. These results suggest that the depressor response to bromocriptine could be related to inhibition of sympathetic outflow without participation of the adrenal medulla. The hyperprolactinemia and enhanced depressor response to bromocriptine observed in DOCA/NaCl animals suggest that the dopaminergic system might be altered in this model of hypertension.
Authors:
S Nagahama; Y F Chen; S Oparil
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  249     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1985 Jul 
Date Detail:
Created Date:  1985-08-13     Completed Date:  1985-08-13     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H64-70     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adrenal Medulla / physiology
Animals
Blood Pressure / drug effects*
Bromocriptine / pharmacology*
Depression, Chemical
Desoxycorticosterone / toxicity*
Dopamine / physiology*
Dopamine Antagonists
Epinephrine / blood
Hexamethonium
Hexamethonium Compounds / pharmacology
Hypertension / chemically induced*
Male
Norepinephrine / blood
Prolactin / blood
Rats
Rats, Inbred Strains
Sodium Chloride / toxicity*
Grant Support
ID/Acronym/Agency:
HL-07457+/HL/NHLBI NIH HHS; HL-22544/HL/NHLBI NIH HHS; HL-25451/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Dopamine Antagonists; 0/Hexamethonium Compounds; 25614-03-3/Bromocriptine; 51-41-2/Norepinephrine; 51-43-4/Epinephrine; 60-26-4/Hexamethonium; 64-85-7/Desoxycorticosterone; 7647-14-5/Sodium Chloride; 9002-62-4/Prolactin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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