title: Growth hormone-releasing factor-induced growth hormone secretion from perifused rat anterior pituitary cells: lack of influence of glucose concentration, and normal responses in pituitary cells from diabetic animals.
abstract: The mechanism responsible for the suppression of GH secretion in hyperglycaemia and hypoglycaemia in rats has been investigated using perifusion of anterior pituitary cells. When perifused with Krebs-Ringer bicarbonate containing normal (5 mmol/l), high (20 mmol/l) and low (1 mmol/l) concentrations of glucose, the GH responses to GH-releasing factor (GRF) were 85 +/- 5, 85.5 +/- 5.4 and 89 +/- 3.0 (S.E.M.)% respectively compared with the initial response to GRF at 5 mmol/l in each column. The mean GH response to GRF from anterior pituitary cells of normal rats was 6.58 +/- 0.88 micrograms/three pituitaries, which was not statistically different form that of cells from rats with streptozotocin-induced diabetes (5.40 +/- 0.68 micrograms/three pituitaries). It is concluded that GH suppression in diabetic rats and during hypoglycaemia is not mediated by changes in the GH response to GRF.
authors.affiliation: Department of Medicine, Royal Postgraduate Medical School, London.
authors.forename: G
authors.initials: G
authors.lastname: Caldwell
authors.forename: G
authors.initials: G
authors.lastname: Hart
authors.forename: E M
authors.initials: EM
authors.lastname: Kohner
authors.forename: J M
authors.initials: JM
authors.lastname: Burrin
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005947:Glucose / Q000494:pharmacology; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D005947:Glucose