STUDIES ON THE IMPACT OF DIETARY-FAT COMPOSITION ON PROTEINURIA IN DIABETIC RATS

Rats with streptozotocin diabetes were pair-fed diets containing 20% b eef tallow (BT), fish oil (FO), or safflower oil (SO) for up to six mo nths. After one month, differences in glucose control were not observe d but rats fed FO had more renal hypertrophy. FO reduced glomerular pr ostaglandin E(2) and 6-keto F-1 alpha, and BT increased thromboxane B- 2 production, but there were no differences in glomerular filtration r ate (GFR) or renal plasma flow (RPF). Animals fed BT needed more insul in after two months than rats fed FO followed by SO. After six months, diabetic rats fed FO had larger relative kidney weights than SO or BT , but a similar pattern was present in non-diabetic controls fed the s ame diets. Diabetic rats fed BT had more proteinuria than diabetic rat s fed SO but not FO. However, FO-fed controls had more proteinuria tha n controls fed SO and similar levels of proteinuria as diabetic rats f ed FO. The composition of dietary fat alters glucose tolerance in diab etic rats after two months. BT increases glomerular thromboxane produc tion and hastens proteinuria compared to SO. FO enhances renal growth and proteinuria, but this effect is independent of the diabetic condit ion.