Original Paper

Insulin Reversal of Impaired Nitrergic Transmission in the Anococcygeus Muscle from Diabetic Rats
Kerrie J. Way, Julianne J. Reid

Pharmacology Research Group, Department of Medical Laboratory Science, RMIT University, Melbourne, Victoria, Australia

Address of Corresponding Author

Pharmacology 1999;59:115-126 (DOI: 10.1159/000028311)

  Key Words

• Anococcygeus muscle, rat
• Diabetes
• Insulin
• Nitrergic neurotransmission
• Nitric oxide

  Abstract

The aim of this study was to investigate whether insulin could reverse the impairment in nitrergic neurotransmission in the anococcygeus muscle from streptozotocin-induced diabetic rats. Relaxations to nitrergic nerve stimulation and sodium nitroprusside were significantly reduced in precontracted muscles from 8- and 4-week diabetic rats compared to the corresponding control rats. Treatment of diabetic rats with Lente insulin (1-12 units/day s.c.) for the final 4 weeks of the 8-week diabetes duration reversed the reductions, but treatment of diabetic rats with insulin for the last week only did not. The impairment of relaxations was also not altered by in vitro exposure of muscles from 8-week diabetic rats to soluble insulin (0.02 units/ml, 2 h). The findings suggest that in vivo insulin treatment can reverse the existing diabetes-induced impairment of nitrergic transmission in rat anococcygeus muscle. However, short-term treatment with insulin, either in vivo or in vitro, does not reverse the impairment.

  Author Contacts

Dr. Julianne J. Reid
Pharmacology Research Group
Department of Medical Laboratory Science, RMIT University
GPO Box 2476V, Melbourne, Victoria 3001 (Australia)
Tel. +61 3 9925 5067, Fax +61 3 9925 3015, E-Mail julier@rmit.edu.au

  Article Information

Received: Received: July 3, 1998
Accepted: February 6, 1999
Number of Print Pages : 12
Number of Figures : 4, Number of Tables : 2, Number of References : 31