Development of insulin sensitivity in white adipose tissue during the suckling-weaning transition in the rat. Involvement of glucose transport and lipogenesis.
The changes of insulin responsiveness of white adipose tissue during the suckling-weaning transition in the rat were investigated in vitro on isolated adipocytes. Insulin binding, glucose transport and glucose metabolism in adipocytes from suckling rats and from rats weaned on to a high-carbohydrate (HC) or a high-fat (HF) diet were compared. Despite similar insulin binding, insulin-stimulated glucose transport rate is lower in adipocytes from suckling rats and HF-weaned rats than in adipocytes from HC-weaned rats. Moreover, whereas insulin markedly stimulates glucose metabolism in adipocytes from HC-weaned rats, glucose metabolism is totally unresponsive to insulin in adipocytes from suckling and HF-weaned rats. This insulin resistance is associated with a very low rate of lipogenesis and low activities of acetyl-CoA carboxylase, fatty acid synthase and pyruvate dehydrogenase.
Issad
T
T
Centre de Recherche sur la Nutrition (CNRS), Meudon-Bellevue, France.
Ferré
P
P
Pastor-Anglada
M
M
Baudon
M A
MA
Girard
J
J
D000273:Adipose Tissue / Q000502:physiology*; D000818:Animals; D000833:Animals, Suckling / Q000502:physiology*; D004041:Dietary Fats / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology*; D007333:Insulin Resistance; D008055:Lipids / Q000096:biosynthesis; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D014886:Weaning
D004041:Dietary Fats; D007328:Insulin; D008055:Lipids; D009004:Monosaccharide Transport Proteins; D005947:Glucose