Functional, structural and molecular aspects of diastolic heart failure in the diabetic (mRen-2)27 rat

Cardiovasc Res. 2007 Nov 1;76(2):280-91. doi: 10.1016/j.cardiores.2007.06.022. Epub 2007 Jun 29.


Objective: Diabetic cardiomyopathy is an increasingly recognized cause of cardiac failure despite preserved left ventricular systolic function. Given the over-expression of angiotensin II in human diabetic cardiomyopathy, we hypothesized that combining hyperglycaemia with an enhanced tissue renin-angiotensin system would lead to the development of diastolic dysfunction with adverse remodeling in a rodent model.

Methods: Homozygous (mRen-2)27 rats and non-transgenic Sprague Dawley (SD) rats were randomized to receive streptozotocin (diabetic) or vehicle (non-diabetic) and followed for 6 weeks. Prior to tissue collection, animals underwent pressure-volume loop acquisition.

Results: Diabetic Ren-2 rats developed impairment of both active and passive phases of diastole, accompanied by reductions in SERCA-2a ATPase and phospholamban along with activation of the fetal gene program. Structural features of diabetic cardiomyopathy in the Ren-2 rat included interstitial fibrosis, cardiac myocyte hypertrophy and apoptosis in conjunction with increased activity of transforming growth factor-beta (p<0.01 compared with non-diabetic Ren-2 rats for all parameters). No significant functional or structural derangements were observed in non-transgenic, SD diabetic rats.

Conclusion: These findings indicate that the combination of enhanced tissue renin-angiotensin system and hyperglycaemia lead to the development of diabetic cardiomyopathy. Fibrosis, and myocyte hypertrophy, a prominent feature of this model, may be a consequence of activation of the pro-sclerotic cytokine, transforming growth factor-beta, by the diabetic state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Apoptosis
  • Diabetes Mellitus, Experimental / complications*
  • Diastole*
  • Disease Models, Animal
  • Heart Failure / genetics
  • Heart Failure / pathology
  • Heart Failure / physiopathology*
  • Male
  • Myocardium / pathology*
  • Rats
  • Rats, Sprague-Dawley
  • Renin / genetics*
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / analysis
  • Streptozocin
  • Transforming Growth Factor beta / analysis


  • Transforming Growth Factor beta
  • Streptozocin
  • Renin
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases