HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 289/4/H1335    most recent 00399.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Vasudevan, H. Articles by McNeill, J. H. Search for Related Content PubMed PubMed Citation Articles by Vasudevan, H. Articles by McNeill, J. H.

Differential regulation of insulin resistance and hypertension by sex hormones in fructose-fed male rats

Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada

Submitted 22 April 2005 ; accepted in final form 7 June 2005

Differences in gender are in part responsible for the development of insulin resistance (IR) and associated hypertension. Currently, it is unclear whether these differences are dictated by gender itself or by the relative changes in plasma estrogen and/or testosterone. We investigated the interrelationships between testosterone and estrogen in the progression of IR and hypertension in vivo in intact and gonadectomized fructose-fed male rats. Treatment with estrogen significantly reduced the testosterone levels in both normal chow-fed and fructose-fed rats. Interestingly, fructose feeding induced a relative increase in estradiol levels, which did not affect IR in both intact and gonadectomized fructose-fed rats. However, increasing the estrogen levels improved insulin sensitivity in both intact and gonadectomized fructose-fed rats. In intact males, fructose feeding increased the blood pressure (140 ± 2 mmHg), which was prevented by estrogen treatment. However, the blood pressure in the fructose-fed estrogen rats (125 ± 1 mmHg) was significantly higher than that of normal chow-fed (113 ± 1 mmHg) and fructose-fed gonadectomized rats. Estrogen treatment did not affect the blood pressure in gonadectomized fructose-fed rats (105 ± 2 mmHg). These data suggest the existence of a threshold value for estrogen below which insulin sensitivity is unaffected. The development of hypertension in this model is dictated solely by the presence or absence of testosterone. In summary, the development of IR and hypertension is governed not by gender per se but by the interactions of specific sex hormones such as estrogen and testosterone.

hyperinsulinemia; fructose hypertensive rat; gender; estrogen; testosterone

This article has been cited by other articles:

				X. Gao, L. Qi, N. Qiao, H. K. Choi, G. Curhan, K. L. Tucker, and A. Ascherio Intake of Added Sugar and Sugar-Sweetened Drink and Serum Uric Acid Concentration in US Men and Women Hypertension, August 1, 2007; 50(2): 306 - 312. [Abstract] [Full Text] [PDF]

				H. Vasudevan, P. R. Nagareddy, and J. H. McNeill Gonadectomy prevents endothelial dysfunction in fructose-fed male rats, a factor contributing to the development of hypertension Am J Physiol Heart Circ Physiol, December 1, 2006; 291(6): H3058 - H3064. [Abstract] [Full Text] [PDF]