Role of the autonomic nervous system in the development of hyperinsulinemia by high-carbohydrate formula feeding to neonatal rats.
An early dietary intervention in the form of a high-carbohydrate (HC) milk formula in neonatal rat pups results in immediate onset of hyperinsulinemia. While increased insulin secretion in HC rats has been shown to be related to hypersensitivity to glucose, the immediate onset of hyperinsulinemia and its persistence throughout the suckling period suggest involvement of multiple systems that enhance insulin secretion in response to increased demand. Evidence presented here in 12-day-old HC rats indicates that altered activity of the autonomic nervous system contributes to enhanced insulin secretory responses to glucose stimulation through increased parasympathetic and decreased sympathetic signaling. Both in vivo and in vitro studies have shown that HC rats secrete significantly higher levels of insulin in response to glucose in the presence of acetylcholine, a cholinergic agonist, while sensitivity to inhibition of insulin secretion by oxymetazoline, an alpha(2a)-adrenergic receptor (alpha(2a)AR) agonist, was reduced. In addition, HC rats showed increased sensitivity to blockade of cholinergic-induced insulin secretion by the muscarinic type 3 receptor (M3R) antagonist 4-diphenylacetoxy-N-methylpiperidine methobromide, as well as increased potentiation of glucose-stimulated insulin secretion by treatment with yohimbine. Increases in islets levels of M3R, phospholipase C-beta1, and protein kinase Calpha mRNAs, as well as decreased alpha(2a)AR mRNA, in 12-day-old HC rats provide a mechanistic connection to the changes in insulin secretion seen in HC rats. In conclusion, altered autonomic regulation of insulin secretion, due to the HC nutritional intervention, contributes to the development of hyperinsulinemia in 12-day-old HC rats.
Mitrani
Paul
P
Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, 140 Farber Hall, 3435 Main St., Buffalo, NY 14214, USA.
Srinivasan
Malathi
M
Dodds
Catherine
C
Patel
Mulchand S
MS
D000109:Acetylcholine / Q000008:administration & dosage / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001341:Autonomic Nervous System / Q000503:physiopathology*; D018678:Cholinergic Agents / Q000008:administration & dosage / Q000494:pharmacology; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005947:Glucose / Q000494:pharmacology; D006946:Hyperinsulinism / Q000209:etiology* / Q000503:physiopathology; D066298:In Vitro Techniques; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007329:Insulin Antagonists / Q000494:pharmacology; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010109:Oxymetazoline / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D019518:Postprandial Period; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015016:Yohimbine / Q000494:pharmacology
C519669:4-diphenylacetoxy-N-methylpiperidine methobromide; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018678:Cholinergic Agents; D004040:Dietary Carbohydrates; D007328:Insulin; D007329:Insulin Antagonists; D018727:Muscarinic Antagonists; D010880:Piperidines; D012333:RNA, Messenger; D015016:Yohimbine; D010109:Oxymetazoline; D005947:Glucose; D000109:Acetylcholine