CNS Involvement in the Glucose Induced Increase of Islet Blood Flow in Obese Zucker Rats

Int J Obes Relat Metab Disord. 1995 Feb;19(2):103-7.

Abstract

Objectives: The aim of this work was to study the role of the central nervous system in the glucose-induced increase in islet blood flow in obese Zucker rats.

Design: A small amount of glucose (9 mg/kg) was injected towards the brain via the left carotid artery in lean obese rats either intact or vagotomized and after a pretreatment with clonidine.

Results: Glucose injection induced a significant increase in plasma insulin level and islet blood flow without a significant change in plasma glucose concentration in both lean and obese rats. Prior vagotomy or clonidine injection resulted in a decrease in glucose-induced islet blood flow. Both the effect of glucose and its reversal were more pronounced in obese rats.

Conclusion: In obese rats, an alteration of the CNS could result in an increase in the parasympathetic tone and a decrease in the sympathetic one. These alterations would in turn contribute to the modifications in islet blood flow.

MeSH terms

  • Animals
  • Blood Flow Velocity
  • Brain / drug effects
  • Brain / physiology*
  • Carotid Arteries
  • Clonidine / pharmacology
  • Female
  • Glucose / administration & dosage
  • Glucose / pharmacology
  • Injections, Intra-Arterial
  • Insulin / blood
  • Islets of Langerhans / blood supply*
  • Obesity / physiopathology*
  • Rats
  • Rats, Zucker
  • Vagotomy

Substances

  • Insulin
  • Glucose
  • Clonidine