Partial A1 adenosine receptor agonist regulates cardiac substrate utilization in insulin-resistant rats in vivo

J Pharmacol Exp Ther. 2009 Jan;328(1):306-11. doi: 10.1124/jpet.108.143594. Epub 2008 Oct 24.

Abstract

Reducing the availability and uptake of fatty acids is a plausible pharmaceutical target to ameliorate glucose intolerance and insulin resistance. CVT-3619 [2-{6-[((1R,2R)-2-hydroxycyclopentyl) amino]purin-9-yl(4S,5S,2R,3R)-5-[(2-fluorophenylthio)methyl]oxolane-3,4-diol] is a partial A(1) adenosine receptor agonist with antilipolytic properties. Aims of the present study were to examine the acute effects of CVT-3619 on whole-body and cardiac glucose and fatty acid kinetics in vivo in normal and diet-induced insulin-resistant rats. Male Sprague-Dawley rats were fed either a chow (CH) or high-fat (HF) diet for 4 weeks. Catheters were then chronically implanted in the carotid artery and jugular vein for sampling and infusions, respectively. After 5 days of recovery, fasted animals (10 h) received either saline or CVT-3619 (0.4 mg/kg bolus + 1 mg/kg/h). Indices of glucose and fatty acid utilization were obtained by the administration of 2-deoxy[(14)C]glucose and [9,10-(3)H]-(R)-2-bromopalmitate. HF feeding resulted in elevated, fasting insulin and free fatty acid (FFA) levels compared with CH. CVT-3619 caused a 64 and 86% reduction of FFA and insulin in HF (p < 0.05) but less (N.S.) in CH diet-fed animals. In HF diet-fed rats, CVT-3619 increased whole-body glucose clearance with no change in fatty acid kinetics. Likewise, analysis of cardiac tissue metabolism showed that CVT-3619 caused an increased glucose but not fatty acid clearance in HF-fed animals. Results show that the acute administration of CVT-3619 lowers circulating fatty acid levels, leading to improved whole-body and cardiac glucose clearance in a model of diet-induced insulin resistance. As such, CVT-3619 may be a treatment option for the restoration of substrate balance in the insulin-resistant heart.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / analogs & derivatives*
  • Adenosine / pharmacology
  • Adenosine A1 Receptor Agonists*
  • Animals
  • Carotid Arteries
  • Dietary Fats
  • Fatty Acids, Nonesterified / blood
  • Fatty Acids, Nonesterified / metabolism
  • Gene Expression Regulation / drug effects
  • Glucose / metabolism*
  • Heart / drug effects
  • Heart / physiology
  • Insulin / physiology
  • Insulin Resistance / physiology*
  • Jugular Veins / physiology
  • Lipolysis
  • Male
  • Models, Animal
  • Myocardium / metabolism*
  • Rats
  • Rats, Sprague-Dawley

Substances

  • 2-(6-((2-hydroxycyclopentyl)amino)purin-9-yl)-5-((2-fluorophenylthio)methyl)oxolane-3,4-diol
  • Adenosine A1 Receptor Agonists
  • Dietary Fats
  • Fatty Acids, Nonesterified
  • Insulin
  • Glucose
  • Adenosine