Picture of a black hole

Strathclyde Open Access research that creates ripples...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of research papers by University of Strathclyde researchers, including by Strathclyde physicists involved in observing gravitational waves and black hole mergers as part of the Laser Interferometer Gravitational-Wave Observatory (LIGO) - but also other internationally significant research from the Department of Physics. Discover why Strathclyde's physics research is making ripples...

Strathprints also exposes world leading research from the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

Greater antiarrhythmic activity of acute 17ß-estradiol in female than male anaesthetized rats: correlation with Ca2+ channel blockade

Philp, K.L. and Hussain, M. and Byrne, N.F. and Diver, M.J. and Hart, G. and Coker, Susan J. (2006) Greater antiarrhythmic activity of acute 17ß-estradiol in female than male anaesthetized rats: correlation with Ca2+ channel blockade. British Journal of Pharmacology, 149. pp. 233-242. ISSN 0007-1188

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

Background and purpose: Female sex hormones may protect pre-menopausal women from sudden cardiac death. We therefore investigated the effects of the main female sex hormone, 17β-estradiol, on ischaemia-induced cardiac arrhythmias and on the L-type Ca2+ current (ICaL). Experimental approach: In vivo experiments were performed in pentobarbital-anaesthetized rats subjected to acute coronary artery occlusion. ICaL was measured by the whole-cell patch-clamp technique, in rat isolated ventricular myocytes. Key results: Acute intravenous administration of 17β-estradiol as a bolus dose followed by a continuous infusion, commencing 10 min before coronary artery occlusion, had dose-dependent antiarrhythmic activity. In female rats 300 ng kg-1 + 30 ng kg−1 min−1 17β-estradiol significantly reduced the number of ventricular premature beats (VPBs) and the incidence of ventricular fibrillation (VF). A ten fold higher dose of 17β-estradiol was required to cause similar effects in male rats. In vitro 17β-estradiol reduced peak ICaL in a concentration-dependent manner. The EC50 was ten-fold higher in male myocytes (0.66 μM) than in females (0.06 μM). Conclusions and implications: These results indicate that 17β-estradiol has marked dose-dependent antiarrhythmic activity that is greater in female rats than in males. A similar differential potency in blocking ICaL in myocytes from female and male rats can account for this effect. This provides an explanation for the antiarrhythmic activity of 17β-estradiol and gender-selective protection against sudden cardiac death.