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Experimental Diabetes Research
Volume 2011 (2011), Article ID 835932, 11 pages
http://dx.doi.org/10.1155/2011/835932
Research Article

Alteration of the Cardiac Sympathetic Innervation Is Modulated by Duration of Diabetes in Female Rats

1Department of Physiology, Faculty of Medicine in Plzeň, Charles University, Lidická 1, 301 00 Plzeň, Czech Republic
2Department of Histology and Embryology, Faculty of Medicine in Plzeň, Charles University, Karlovarská 48, 301 00 Plzeň, Czech Republic

Received 20 December 2010; Accepted 13 May 2011

Academic Editor: Bernard Portha

Copyright © 2011 Jitka Švíglerová et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

To evaluate the sympathetic innervation of the female diabetic heart, resting heart rate and sympathetic tone were assessed in vivo, and effect of tyramine on spontaneous beating rate, norepinephrine atrial concentrations, uptake, and release were determined in vitro in streptozotocin- (STZ-) treated rats and respective controls aged 3 months to 2 years. Resting bradycardia, decreased sympathetic tone, deceleration of spontaneous beating rate, and slightly declining carrier-mediated, but preserved exocytotic norepinephrine release from the atria were found in younger diabetic rats while the reactivity of the right atria to tyramine was not affected with age and disease duration. Diabetic two-year-old animals displayed symptoms of partial spontaneous recovery including normoglycemia, increased plasma insulin concentrations, fully recovered sympathetic tone, but putative change, in releasable norepinephrine tissue stores. Our data suggested that female diabetic heart exposed to long-lasting diabetic conditions seems to be more resistant to alteration in sympathetic innervation than the male one.