Oestradiol and insulin secretion in the rat: when does oestradiol start stimulating the insulin release?
Long-term oestradiol treatments induce hyperinsulinism and low glycaemia. Time-related experiments were performed to determine when this effect appears in islets from treated rats. Oestradiol first inhibited the insulin secretion for 2 days and later stimulated the B cells functioning from the 3rd day of treatment onward. This effect of oestradiol was dose-dependent. The beginning of this stimulating action of oestradiol was characterized by a normal tolerance to glucose and normoglycaemia, still maintained in spite of hyperinsulinaemia, hypoglucagonaemia and lowered food intake. This suggested that the long-term oestradiol-induced low glycaemia was a consequence of the hyperinsulinism.
Faure
A
A
Laboratoire d'Endocrinologie, Université de Bordeaux I, France.
Haouari
M
M
Sutter
B C
BC
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005951:Glucose Tolerance Test; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D004958:Estradiol