Possible contribution of the non-proteolytic activation of prorenin to the development of insulin resistance in fructose-fed rats

Exp Physiol. 2009 Sep;94(9):1016-23. doi: 10.1113/expphysiol.2009.048108. Epub 2009 Jun 5.

Abstract

Recent studies have shown that blocking non-proteolytically activated prorenin with a decoy peptide for the handle region of the prorenin prosegment (HRP) inhibits the development of microvascular complications in diabetic animals. In the present study, we investigated whether non-proteolytic activation of prorenin contributes to the development of fructose-induced insulin resistance. Rats were fed a standard diet (n = 10), a 60% high fructose diet (n = 16), or a high fructose diet + HRP (0.1 mg kg(-1) day(-1), n = 16) for 10 weeks. Fructose-fed rats showed higher systolic blood pressure (SBP), fasting plasma triglycerides, total cholesterol and insulin levels; which, except for SBP, were suppressed by HRP. The responses of plasma glucose and insulin levels to oral glucose loading were significantly greater in fructose-fed rats than in standard diet-fed rats. The HRP normalized the enhanced responses of plasma glucose and insulin levels that were observed in fructose-fed rats. Moreover, HRP suppressed the enhanced prorenin activation and angiotensin II formation in the soleus muscle of fructose-fed rats. These data suggest that local angiotensin II generation in skeletal muscle, induced by non-proteolytic activation of prorenin, contributes to the development of insulin resistance induced by a high fructose diet.

MeSH terms

  • Adipocytes / cytology
  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Adiponectin / genetics
  • Angiotensin II / biosynthesis
  • Animals
  • Base Sequence
  • Blood Glucose / metabolism
  • Blood Pressure / drug effects
  • Blood Pressure / physiology
  • Cell Size / drug effects
  • Cholesterol / blood
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / adverse effects
  • Enzyme Activation / drug effects
  • Fatty Acids, Nonesterified / blood
  • Fructose / administration & dosage*
  • Fructose / adverse effects
  • Insulin / blood
  • Insulin Resistance / genetics
  • Insulin Resistance / physiology*
  • Male
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / metabolism
  • Oligopeptides / pharmacology
  • Prorenin Receptor
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cell Surface / genetics
  • Renin / metabolism*
  • Triglycerides / blood

Substances

  • Adiponectin
  • Blood Glucose
  • Dietary Carbohydrates
  • Fatty Acids, Nonesterified
  • Insulin
  • Oligopeptides
  • RNA, Messenger
  • Receptors, Cell Surface
  • Triglycerides
  • handle-region peptide, rat
  • Angiotensin II
  • Fructose
  • Cholesterol
  • Renin
  • Prorenin Receptor