Abstract

OBESITY ASSOCIATED MITOCHONDRIAL DYSFUNCTION: EVIDENCES FROM WNIN MUTANT RATS

Nirupama Lal, K. Rajender Rao, Pothani Suresh, Md. Shahidul Islam, Nemani Harishankar, Nappan Veettil Giridharan, Bharati Kulkarni and Vijayalakshmi Venkatesan*

Abstract

WNIN/Obese mutant rats portray features of obesity such as higher body weight with hyperinsulinemia which is similar to the preclinical /clinical features of obesity induced type 2 diabetes in humans. Using this mutant model several previous studies have unequivocally demonstrated metabolic insults and suggested its application as a potential model to study the metabolic syndrome vis-a-vis elite complications. The aim of the current study was to compare the mitochondrial swelling in female WNIN/Obese (O) rats at different age (i.e., 35, 90, 180 and 360 days old) to that of WNIN-parental (W) and WNIN/Ob lean (L) rats as controls along with some physical and biochemical parameters. The whole body dual energy X-ray absorptiometry (DXA) and biochemical analysis of fasting plasma were performed. Liver mitochondria were isolated and subjected to Ca2+-induced swelling study. Obese rats of the designated WNIN/Obese (O) group showed decreased susceptibility to Ca2+- induced swelling. Additionally, its drastically worsened physical and biochemical indices compared to WNIN-parental (W) and WNIN/Ob lean (L) suggest that obesity is one of the factors to alter the permeability of inner mitochondrial membrane at least in this experimental condition.

Keywords: WNIN obese mutant rat; obesity; liver mitochondria; swelling; DXA.