Document Detail


Testosterone suppresses endothelium-dependent dilation of rat middle cerebral arteries.
MedLine Citation:
PMID:  14551047     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Little is known about vascular effects of testosterone. We previously reported chronic testosterone treatment increases vascular tone in middle cerebral arteries (MCA; 300 microm diameter) of male rats. In the present study, we investigated the hypothesis that physiological levels of circulating testosterone affect endothelial factors that modulate cerebrovascular reactivity. Small branches of MCA (150 microm diameter) were isolated from orchiectomized (ORX) and testosterone-treated (ORX+T) rats. Intraluminal diameters were recorded after step changes in intraluminal pressure (20-100 Torr) in the absence or presence of N(G)-nitro-L-arginine-methyl ester (L-NAME), a nitric oxide synthase (NOS) inhibitor; indomethacin, a cyclooxygenase (COX) inhibitor; and/or apamin and charybdotoxin (CTX); and K(Ca) channel blockers used to inhibit endothelium-derived hyperpolarizing factors (EDHF). At intraluminal pressures >or=60 Torr, arteries from ORX+T developed greater tone compared with ORX arteries. This difference was abolished by removal of the endothelium but remained after treatment of intact arteries with indomethacin or L-NAME. In addition, testosterone treatment had no effect on cerebrovascular production of endothelin-1 or prostacyclin nor did it alter protein levels of endothelial NOS or COX-1. Endothelium removal after L-NAME/indomethacin exposure caused an additional increase in tone. Interestingly, the latter effect was smaller in arteries from ORX+T, suggesting testosterone affects endothelial vasodilators that are independent of NOS and COX. Apamin/CTX, in the presence of L-NAME/indomethacin, abolished the difference in tone between ORX and ORX+T and resulted in vessel diameters similar to those of endothelium-denuded preparations. In conclusion, testosterone may modulate vascular tone in cerebral arteries by suppressing EDHF.
Authors:
Rayna J Gonzales; Diana N Krause; Sue P Duckles
Related Documents :
24590687 - Percutaneous pulmonary vein stenosis angioplasty complicated by rupture: successful ste...
12163347 - Comparison of vasodilators in human internal mammary artery: ghrelin is a potent physio...
15838257 - Amiodarone acutely inhibits vascular activity of endothelin-converting enzymes.
16428917 - Influence of ephedrine and the role of alpha subtype adrenoreceptors in the vascular be...
17416477 - Removed: assessment of pulmonary venous variation by multidetector row ct: clinical imp...
1739227 - Pericardiotomy improves left ventricular compliance during sepsis-induced pulmonary art...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2003-10-09
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  286     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2004 Feb 
Date Detail:
Created Date:  2004-01-12     Completed Date:  2004-03-09     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H552-60     Citation Subset:  IM    
Affiliation:
Department of Pharmacology, College of Medicine, University of California, Irvine 92697-4625, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Apamin / pharmacology
Body Weight
Charybdotoxin / pharmacology
Cyclooxygenase 1
Cyclooxygenase Inhibitors / pharmacology
Endothelium, Vascular / drug effects,  physiology*
Indomethacin / pharmacology
Isoenzymes / metabolism
Male
Membrane Proteins
Middle Cerebral Artery / drug effects,  physiology*
Muscle Tonus
Muscle, Smooth, Vascular / drug effects,  physiology*
NG-Nitroarginine Methyl Ester / pharmacology
Prostaglandin-Endoperoxide Synthases / metabolism
Rats
Rats, Inbred F344
Testosterone / blood,  pharmacology*
Vasodilation / drug effects*
Grant Support
ID/Acronym/Agency:
HL-50775/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Cyclooxygenase Inhibitors; 0/Isoenzymes; 0/Membrane Proteins; 115422-61-2/Charybdotoxin; 24345-16-2/Apamin; 50903-99-6/NG-Nitroarginine Methyl Ester; 53-86-1/Indomethacin; 58-22-0/Testosterone; EC 1.14.99.1/Cyclooxygenase 1; EC 1.14.99.1/Prostaglandin-Endoperoxide Synthases; EC 1.14.99.1/Ptgs1 protein, rat

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


Previous Document:  In vivo expression and function of recombinant GTPCH I in the rabbit carotid artery.
Next Document:  Inhibition of glucose uptake in murine cardiomyocyte cell line HL-1 by cardioprotective drugs dilaze...