Proceedings of The Physiological Society

Mitochondria: Form and function (London, UK) (2017) Proc Physiol Soc 38, PC15

Poster Communications

Effects of type 1 and type 2 diabetes on the structure and pattern of distribution of ventricular mitochondria in the rat heart

E. Adeghate1, C. Howarth1, K. R. Bidasee3, J. Singh2

1. College of Medicine, United Arab Emirates University, United Arab Emirates University, Al Ain, United Arab Emirates. 2. University of Central Lancashire, Preston, United Kingdom. 3. University of Nebraska Medical Center, Omaha, Nebraska, United States.

Diabetes mellitus (DM) is associated with hyperglycaemia (HG). Chronic HG induces oxidative stress and glycation of intracellular proteins (1). These events result in abnormal conformational and structural changes in the organelles of cardiomyocytes. One of the most sensitive organelles to respond to these changes is the mitochondrion. The ultrastructure and the pattern of distribution of mitochondria in streptozotocin (STZ)-induced diabetic rat, a model of type 1 and in the Goto-Kakizaki (GK) rat, a model of type 2 DM was investigated using electron microscopy (EM). The study was performed on 3-month and 18-month old STZ-induced diabetic rats and age-matched Wistar controls. The structure and pattern of distribution of mitochondria was also investigated in GK rats for comparison. Left ventricular tissue samples from diabetic and control groups were fixed in Karnovsky solution, dehydrated in ethanol, and embedded in resin. Ultrathin sections were cut with diamond knife, counterstained with uranyl acetate and lead citrate and viewed with Philips EM. The results showed a significant (Student's t-test; p<0.05) reduction in the number of mitochondria. In addition, the size of mitochondria is significantly (p <0.05) reduced in cardiomyocytes of STZ-induced and GK diabetic rats compared to control. This study has demonstrated severe abnormality in the structure and pattern of distribution of mitochondria in cardiomyocytes of both STZ-induced and GK diabetic rats when compared to controls. These mitochondrial anomalies may underlie the functional dysfunction observed in diabetic patients.

Where applicable, experiments conform with Society ethical requirements