AJP - Regulatory, Integrative and Comparative Physiology, Vol 263, Issue 4 785-R789, Copyright © 1992 by American Physiological Society

ARTICLES

Whole body insulin sensitivity in Osborne-Mendel and S 5B/Pl rats eating a low- or high-fat diet

T. A. Buchanan, J. S. Fisler, S. Underberger, G. F. Sipos and G. A. Bray
Department of Medicine, University of Southern California Medical School, Los Angeles 90033.

To determine whether whole body insulin sensitivity differs between a rat strain that does not (S 5B/Pl) and a strain that does [Osborne-Mendel (OM)] become obese when eating a high-fat diet, we performed euglycemic clamp studies in animals from each strain during low- and high-fat feeding. Clamps were performed after 2 days ("initial clamp") and 9 days ("final clamp") on each diet. Plasma glucose and insulin levels during the final 60 min of initial and final clamps were similar in S 5B/Pl and OM rats regardless of diet. Insulin sensitivity, measured as the glucose clearance rate during the final 60 min of the clamp, averaged 35 +/- 3 ml.kg-1.min-1 in S 5B/Pl rats after 2 days on a low-fat diet. This did not change significantly during an additional 7 days on the low-fat diet. The high-fat diet was associated with a 13% reduction in insulin sensitivity after 2 days and a 30% reduction after 9 days in S 5B/Pl rats. OM rats exhibited similar patterns of insulin sensitivity during low- and high-fat diets, albeit at lower insulin sensitivity overall (P < 0.0005 vs. S 5B/Pl). Mean glucose clearance after 2 days on the low-fat diet was 27 +/- 2 mg.kg-1.min-1 and did not change significantly during seven more days of low-fat feeding. The high-fat diet was associated with a 19% reduction in glucose clearance after 2 days and a 38% reduction after 9 days in OM rats. The magnitude of reduction in insulin sensitivity during high-fat diets did not differ significantly between strains.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				S. T. Mathews, G. P. Singh, M. Ranalletta, V. J. Cintron, X. Qiang, A. S. Goustin, K.-L. C. Jen, M. J. Charron, W. Jahnen-Dechent, and G. Grunberger Improved Insulin Sensitivity and Resistance to Weight Gain in Mice Null for the Ahsg Gene Diabetes, August 1, 2002; 51(8): 2450 - 2458. [Abstract] [Full Text] [PDF]

				R. Burcelin, V. Crivelli, A. Dacosta, A. Roy-Tirelli, and B. Thorens Heterogeneous metabolic adaptation of C57BL/6J mice to high-fat diet Am J Physiol Endocrinol Metab, April 1, 2002; 282(4): E834 - E842. [Abstract] [Full Text] [PDF]

				X. Lin, M. R. Chavez, R. C. Bruch, G. E. Kilroy, L. A. Simmons, L. Lin,, H. D. Braymer, G. A. Bray, and D. A. York The Effects of a High Fat Diet on Leptin mRNA, Serum Leptin and the Response to Leptin Are Not Altered in a Rat Strain Susceptible to High Fat Diet-Induced Obesity J. Nutr., October 1, 1998; 128(10): 1606 - 1613. [Abstract] [Full Text]

				J. Wang, J. T. Alexander, P. Zheng, H. J. Yu, J. Dourmashkin, and S. F. Leibowitz Behavioral and endocrine traits of obesity-prone and obesity-resistant rats on macronutrient diets Am J Physiol Endocrinol Metab, June 1, 1998; 274(6): E1057 - E1066. [Abstract] [Full Text] [PDF]