Arginine-vasopressin mediates central and peripheral glucose regulation in response to carotid body receptor stimulation with Na-cyanide.
Hypoxic stimulation of the carotid body receptors (CBR) results in a rapid hyperglycemia with an increase in brain glucose retention. Previous work indicates that neurohypophysectomy inhibits this hyperglycemic response. Here, we show that systemic arginine vasopressin (AVP) induced a transient, but significant, increase in blood glucose levels and increased brain glucose retention, a response similar to that observed after CBR stimulation. Comparable results were obtained after intracerebral infusion of AVP. Systemic AVP-induced changes were maintained in hypophysectomized rats but were not observed after adrenalectomy. Glycemic changes after CBR stimulation were inhibited by pharmacological blockage of AVP V1a receptors with a V1a-selective receptor antagonist ([beta-Mercapto-beta,beta-cyclopentamethylenepropionyl1,O-me-Tyr2, Arg8]-vasopressin). Importantly, local application of micro-doses of this antagonist to the liver was sufficient to abolish the hyperglycemic response after CBR stimulation. These results suggest that AVP is a mediator of the hyperglycemic reflex and cerebral glucose retention following CBR stimulation. We propose that hepatic activation of AVP V1a receptors is essential for this hyperglycemic response.
CUIB, Universidad de Colima, Ave. 25 de Julio s/n, Colima, Col. 28045, México. checo@cgic.ucol.mx
Sergio
S
Montero
Herón
H
Mendoza
Victoria
V
Valles
Mónica
M
Lemus
Ramón
R
Alvarez-Buylla
Elena R
ER
de Alvarez-Buylla
D000311:Adrenal Glands / Q000502:physiology; D000315:Adrenalectomy; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000502:physiology*; D001923:Brain Chemistry; D002344:Carotid Body / Q000737:chemistry / Q000502:physiology*; D002395:Catecholamines / Q000378:metabolism; D002628:Chemoreceptor Cells / Q000187:drug effects* / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006943:Hyperglycemia / Q000139:chemically induced / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000502:physiology; D012966:Sodium Cyanide / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology
D065092:Antidiuretic Hormone Receptor Antagonists; D002395:Catecholamines; D004791:Enzyme Inhibitors; D017483:Receptors, Vasopressin; D014667:Vasopressins; D001127:Arginine Vasopressin; C066604:oxytocin, beta-mercapto-beta,beta-cyclopentamethylenepropionic acid-Trp(2)-Phe(3)-Ile(4)-Arg(8)-; D005934:Glucagon; D005947:Glucose; D012966:Sodium Cyanide