Effects of anaesthesia on insulin sensitivity and metabolic parameters in Wistar rats.

We compared the effects of two different anaesthetics, sodium pentobarbital (65 mg/kg) and ketamine (30 mg/kg) plus xylazine (4 mg/kg) (KX) on insulin sensitivity, fasting glycaemia, insulinaemia and free fatty acids (FFA). Four groups of Wistar rats were used: KX group (n=6), pentobarbital group (n=6), high-sucrose diet group (n=6) and the conscious group (n=6). The insulin tolerance test (ITT) was used to measure insulin sensitivity, and metabolic biomarkers were determined using commercial kits. Pentobarbital did not alter plasma insulin, glucose, FFA or the ITT results compared to conscious animals. In contrast, KX anaesthesia induced hyperglycaemia, increased serum FFA and altered the ITT results compared to the conscious animal group. Moreover, under pentobarbital anaesthesia, the ITT proved to be a suitable method to detect insulin resistance in an animal model of diet-induced insulin resistance. We concluded that sodium pentobarbital anaesthesia should be used in metabolic studies since it does not interfere with plasma glucose, insulin, FFA or insulin sensitivity quantification in Wistar rats.