The passive coping Roman Low Avoidance rat, a non-obese rat model for insulin resistance

The aim of the study was develop to an animal model that links coping style to insulin resistance. We hypothesized that the psychogenetically selected Roman Low Avoidance (RLA) rats may serve as such a model. To test this hypothesis, we submitted both RLA and Roman High avoidance (RHA) rats to a series of intravenous glucose tolerance tests (IVGTT). These IVGTT were followed by post mortem metabolic characterization of the selection lines. It was found that plasma insulin levels are markedly elevated in the passively coping RLA rat, both in baseline conditions and during the intravenous glucose tolerance tests. The elevation in plasma insulin was accompanied with increased levels of plasma corticosterone, FFA, leptin and triglycerides but not by changes in body weight. We conclude that the passive, highly emotional RLA rat is metabolically different from both the RHA rat and the standard control Wistar rat and may serve as a non-obese animal model for insulin resistance.