title: Glucoreceptors located in the brain mediate NPY release induced by hypoglycemia in normal men.
abstract: The NPY secretory pattern after an insulin tolerance test (ITT) (0.15 IU/kg body weight) was evaluated in 8 normal men. They were infused with normal saline (control test), glucose or fructose. Insulin-induced hypoglycemia produced a significant increment in serum NPY in the control test. The infusion of fructose was unable to change the NPY secretory pattern during insulin-induced hypoglycemia. In contrast, the NPY increase during ITT was completely abolished when the concomitant infusion of glucose prevented insulin-induced hypoglycemia. These results exclude a direct role of hyperinsulinemia in the mechanism underlying the stimulation of NPY secretion during ITT. Furthermore, since glucose but not fructose crosses the blood-brain-barrier (BBB), the NPY increase during ITT appears to be generated by low glucose concentrations at the level of glucosensitive areas located inside the brain.
authors: Department of Internal Medicine and Biomedical Sciences, University of Parma, Parma, Italy. vittorio.coiro@unipr.it
authors: Vittorio
authors: V
authors: Coiro
authors: Riccardo
authors: R
authors: Volpi
authors: Simona
authors: S
authors: Cataldo
authors: Maria Grazia
authors: MG
authors: Magotti
authors: Claudio
authors: C
authors: Giumelli
authors: Francesca
authors: F
authors: Russo
authors: Adriano
authors: A
authors: Stella
authors: Paolo
authors: P
authors: Chiodera
mesh_terms: D000328:Adult; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D005632:Fructose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000503:physiopathology*; D007328:Insulin / Q000494:pharmacology; D008297:Male; D009478:Neuropeptide Y / Q000097:blood*; D011956:Receptors, Cell Surface
chemical_list: D007328:Insulin; D009478:Neuropeptide Y; D011956:Receptors, Cell Surface; C027786:glucose receptor; D005632:Fructose; D005947:Glucose