INSULIN SENSITIVITY OF ADIPOSE TISSUE AND OF DIAPHRAGM IN RATS ADAPTED TO PERIODIC HYPERPHAGIA

In the present paper the authors have investigated the sensitivity of adipose tissue and diaphragm to insulin in rats adapted to periodic hyperphagia. Insulin was administered by the intraperitoneal route in amounts that did not affect the blood sugar level. The incorporation of labelled glucose, administered simultaneously with insulin, into lipids of parametrial adipose tissue and into glycogen of the diaphragm was investigated, together with the glycogen content of the diaphragm. Moreover, the authors investigated the influence of insulin added to the medium on the glycogen content of the isolated diaphragm. It was found that adipose tissue of adapted rats responded to insulin at all levels used, more sensitively than adipose tissue of control rats fed ad libitum. On the other hand, no differences were found in the sensitivity of the diaphragm to insulin either in vivo or in vitro. The relationship between morphological and functional changes in the adipose tissue of adapted rats and the increased reactivity of this tissue to insulin is discussed. © 1969 Springer-Verlag.