Binding of low-density lipoprotein to monolayer cultures of rat hepatocytes is increased by insulin and decreased by dexamethasone.
Rat hepatocytes were maintained in monolayer culture for 20 h in the presence of 10% (v/v) newborn calf serum and then for a further 1-24 h in serum-free medium containing 2 g bovine serum albumin/l. The specific binding of human 125I-LDL to two distinct sites was then measured at 4 degrees C. Binding to site 1 was displaced by dextran sulphate while that to site 2 was not. The presence of 1-100 nM insulin for 24 h in the second incubation significantly increased binding to site 1. Significant increases were also seen when cells were incubated with 10 nM insulin for 1 h. No significant effects of insulin on binding to site 2 were observed. In contrast, 10 nM-1 microM dexamethasone decreased binding to both sites. The effects of these hormones were mutually antagonistic.
Salter
A M
AM
Fisher
S C
SC
Brindley
D N
DN
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D008077:Lipoproteins, LDL; D003907:Dexamethasone