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This Article Full Text Full Text (PDF) All Versions of this Article: 293/3/H1553    most recent 00151.2007v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Yang, Y. Articles by Rubin, L. J. Search for Related Content PubMed PubMed Citation Articles by Yang, Y. Articles by Rubin, L. J.

Influence of sex, high-fat diet, and exercise training on potassium currents of swine coronary smooth muscle

¹Departments of Biomedical Sciences, ²Medical Pharmacology and Physiology, ³Nutrition Science, ⁴Dalton Cardiovascular Research Center, ⁵Center for Diabetes and Cardiovascular Health, and ⁶Center for Gender Physiology and Environmental Adaptations. University of Missouri, Columbia, Missouri

Submitted 6 February 2007 ; accepted in final form 24 May 2007

Potassium channels in vascular smooth muscle (VSM) control vasodilation and are potential regulatory targets. This study evaluated effects of sex differences, exercise training (EX), and high-fat diet (HF) on K⁺ currents (I_K) of coronary VSM cells. Yucatan male and female swine were assigned to either sedentary confinement (SED), 16 wk of EX, 20 wk of HF, or 20 wk of HF with 16 wk of EX (HF-EX). VSM cells of normal-diet SED animals exhibited three components of I_K: 4-aminopyridine-sensitive I_K(KV), TEA-sensitive I_K(BK), and 4-aminopyridine + TEA-insensitive I_K. Females exhibited significantly higher basal I_K than males in the same group. EX increased basal I_K in males and females. HF reduced I_K in males and females and nullified effects of EX. Endothelin-1 increased I_K significantly in males but not in females. In the presence of endothelin-1, 1) I_K(KV) was similar in SED males and females and EX increased I_K(KV) to a greater extent in males than in females and 2) I_K(BK) was greater in SED females than in males and EX increased I_K(BK) to a greater extent in males, resulting in I_K(BK) similar to EX females. Importantly, HF nullified effects of EX on I_K(KV) and I_K(BK). These data indicate that basal I_K of SED female swine is inherently greater than that shown in SED males and that males require EX to achieve comparable levels of I_K. Importantly, HF reduced I_K in males and females and nullified effects of EX, suggesting HF abrogates beneficial effects of EX on coronary smooth muscle.

gender; potassium channel; hyperlipidemia