Right atria from rats rendered diabetic by injection of streptozocin (STZ-D) for 8–10 wk are supersensitive to the negative chronotropic effects of muscarinic agonists but have decreased levels of muscarinic receptors and acetylcholinesterase activity. Insulin treatment completely prevents the development of these changes. The proportion of atrial muscarinic receptors displaying high-affinity agonist binding is lower in STZ-D rats; however, the sensitivity of high-affinity agonist binding to regulation by a guanine nucleotide (5′-guanylylimidodiphosphate) is greater in atria from diabetic rats. Again, insulin treatment eliminates these differences. These findings indicate that alterations in atrial muscarinic systems in STZ-D rats are a consequence of the elaboration of the diabetic state and suggest that an alteration of functional muscarinic receptor–G protein coupling contributes to the altered physiological responsiveness of the heart in diabetes.
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Original Articles|
December 01 1989
Insulin Prevention of Altered Muscarinic Receptor–G Protein Coupling in Diabetic Rat Atria
Robert S Aronstam;
Robert S Aronstam
Department of Pharmacology and Toxicology, Medical College of Georgia
Augusta, Georgia
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Gerald O Carrier
Gerald O Carrier
Department of Pharmacology and Toxicology, Medical College of Georgia
Augusta, Georgia
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Address correspondence and reprint requests to Robert S. Aronstam, PhD, Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912–2300.
Diabetes 1989;38(12):1611–1616
Article history
Received:
September 12 1988
Revision Received:
August 03 1989
Accepted:
August 03 1989
PubMed:
2573555
Citation
Robert S Aronstam, Gerald O Carrier; Insulin Prevention of Altered Muscarinic Receptor–G Protein Coupling in Diabetic Rat Atria. Diabetes 1 December 1989; 38 (12): 1611–1616. https://doi.org/10.2337/diab.38.12.1611
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