Intra-ventromedial hypothalamic injection of cholinergic agents induces rapid hyperglycemia, hyperlactatemia and gluconeogenesis activation in fed, conscious rats.
Microinjections of carbachol (50 nmol) or neostigmine (25 nmol) in 0.5 ml saline into the ventromedial nucleus of the hypothalamus (VMH) (but not into the lateral hypothalamic area) of fed, conscious rats produced marked increases in plasma glucose and lactate, which were suppressed or markedly reduced by previous adrenodemedullation. The rate of incorporation of 14C from infused bicarbonate (0.60 microliter, 0.20 microCi/min), an index of gluconeogenic activity, increased significantly after VMH administration of neostigmine. The data suggest that cholinergic synapses in the VMH participate of a central glucoregulatory system that increases hepatic glucose production mainly through a stimulation of adrenal medulla epinephrine secretion.
Brito
N A
NA
Department of Biochemistry, School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
Brito
M N
MN
Kettelhut
I C
IC
Migliorini
R H
RH
D000313:Adrenal Medulla / Q000502:physiology; D000818:Animals; D002217:Carbachol / Q000008:administration & dosage; D005502:Food; D005943:Gluconeogenesis / Q000187:drug effects*; D006943:Hyperglycemia / Q000139:chemically induced*; D007026:Hypothalamic Area, Lateral / Q000187:drug effects*; D007033:Hypothalamus, Middle / Q000187:drug effects*; D007773:Lactates / Q000097:blood*; D019344:Lactic Acid; D008297:Male; D008845:Microinjections; D009388:Neostigmine / Q000008:administration & dosage; D010277:Parasympathomimetics / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D007773:Lactates; D010277:Parasympathomimetics; D019344:Lactic Acid; D009388:Neostigmine; D002217:Carbachol