[Effect of hyperinsulinemia on liver insulin receptors of the growing rat subjected to energy restriction].
Two experiments (I and II) were carried out to study the interaction of insulin with amino acid metabolism in rats subjected to a restricted energy allowance (Grizard et al., 1975). 61 male rats, weighing 94 g at the beginning of the experiments, were divided into 4 groups and fed every 4 hrs. Group T was fed a balanced diet, and groups -E1, -E2 and -E3 were given a restricted energy allowance (table 1). The rats of group -E3 were injected with insulin at 11 a. m. every day, and those of group -E2 at that hour on the day they were killed. When the animals of a group had a mean body weight of 157 g, they were killed between 2 p. m. and 6 p. m., i. e. between two meals. Plasma insulin and insulin binding to liver plasma membranes were recorded. Reducing dietary energy intake resulted in a small decrease of postprandial plasma insulin and in a small increase of the plasma insulin clearance rate (table 2). It also augmented (125I) iodoinsulin binding to liver plasma membranes (fig. 1). This change could explain the increment of the liver protein synthesis observed in such animals (Arnal, Fauconneau and Pech, 1972). Exogenous insulin induced a resistance to insulin effects (Grizard, Prugnaud and Pion, 1977), and caused a large increase of plasma insulin and a small decline in (125I) iodoinsulin binding to liver plasma membranes for 3 to 5 h after the injection (fig. 1). A large increment in insulin binding was then noted (fig. 1). Increased insulin binding and decreased plasma insulin might be correlated. The enhanced insulin binding could not explain the resistance to the effects of insulin.
D000818:Animals; D001835:Body Weight; D002462:Cell Membrane / Q000378:metabolism; D005508:Food Deprivation; D006946:Hyperinsulinism / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D011919:Rats, Inbred Strains; D011972:Receptor, Insulin / Q000378:metabolism*
D007328:Insulin; D011972:Receptor, Insulin
Influence de l'hyperinsulinémie sur les récepteurs d'insuline dans le foie du rat en croissance soumis à une restriction énergétique.