Collagen metabolism in the myocardium from streptozotocin-diabetic rats

The effect of diabetes on myocardial collagen metabolism was investigated in rats. Diabetes was induced by an i.v. injection of streptozotocin (60 mg/kg). The animals were killed after 3, 6, 18, or 26 wk of diabetes. Urinary glucose levels were measured by Tes-Tape. The myocardium was quickly removed and homogenized. Collagen was estimated by hydroxyproline content. Collagen synthesis was measured by 14C-proline incorporation. Myocardial collagen concentration and collagen synthesis was not altered in the diabetic rats. Collagen concentration did appear to increase in the 18- and 26-wk rats, but this was probably an age-related phenomenon. These results suggest that diabetes does not alter collagen metabolism in rats.