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.

• MeSH
• Atropine pharmacology   MeSH
• Time Factors MeSH
• Diabetes Mellitus, Experimental chemically induced   metabolism   physiopathology   MeSH
• Insulin metabolism   MeSH
• Rats MeSH
• Humans MeSH
• Metipranolol pharmacology   MeSH
• Sex Characteristics MeSH
• Rats, Wistar MeSH
• Heart drug effects   innervation   physiopathology   MeSH
• Heart Rate drug effects   physiology   MeSH
• Streptozocin MeSH
• Sympathetic Nervous System drug effects   pathology   physiopathology   MeSH
• Sympatholytics pharmacology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Atropine MeSH
• Insulin MeSH
• Metipranolol MeSH
• Streptozocin MeSH
• Sympatholytics MeSH