Ameliorating Effects of Sulfonylurea Drugs on Insulin Resistance in Otsuka Long-Evans Tokushima Fatty Rats.
- Author:
Jeong Kwon PARK
1
,
2
;
Sang Pyo KIM
;
Dae Kyu SONG
Author Information
- Publication Type:Original Article
- Keywords: Diabetic rat; Sulfonylureas; KATP channel; Glucose transporters
- MeSH: Animals; Benzoic Acid; Blood Glucose; Carbamates; Drinking Water; Gliclazide; Glucose; Immunohistochemistry; Insulin; Insulin Resistance; KATP Channels; Liver; Muscle, Skeletal; Phenotype; Piperidines; Potassium; Rats; Rats, Inbred OLETF; Receptor, Insulin; Sulfonylurea Compounds
- From:The Korean Journal of Physiology and Pharmacology 2008;12(1):7-12
- CountryRepublic of Korea
- Language:English
- Abstract: OLETF (Otsuka Long-Evans Tokushima Fatty) rats are characterized by obesity-related insulin resistance, which is a phenotype of type 2 diabetes. Sulfonylurea drugs or benzoic acid derivatives as inhibitors of the ATP-sensitive potassium (KATP) channel are commercially available to treat diabetes. The present study compared sulfonylurea drugs (glimepiride and gliclazide) with one of benzoic acid derivatives (repaglinide) in regard to their long-term effect on ameliorating insulin sensitivity in OLETF rats. Each drug was dissolved and fed with drinking water from 29 weeks of age. On high glucose loading at 45 weeks of age, response of blood glucose recovery was the greatest in the group treated with glimepiride. On immunohistochemistry analysis for the Kir6.2 subunit of KATP channels, insulin receptor beta-subunits, and glucose transporters (GLUT) type 2 and 4 in liver, fat and skeletal muscle tissues, the sulfonylurea drugs (glimepiride and gliclazide) were more effective than repaglinide in recovery from their decreased expressions in OLETF rats. From these results, it seems to be plausible that KATP-channel inhibitors containing sulfonylurea moiety may be much more effective in reducing insulin resistance than those with benzoic acid moiety. In contrast to gliclazide, non-tissue selectivity of glimepiride on KATP channel inhibition may further strengthen an amelioration of insulin sensitivity unless considering other side effects.
