EFFECT OF MYOINOSITOL SUPPLEMENTATION ON THE DEVELOPMENT OF RENAL PATHOLOGICAL-CHANGES IN THE COHEN DIABETIC (TYPE-2) RAT

A lower concentration of intracellular myo-inositol has been implicate d in the development of diabetic nephropathy. This was based on short- term studies showing that early administration of aldose reductase inh ibitors or myo-inositol supplementation reduces increased glomerular f iltration rate and partly reduces increased urinary albumin excretion in streptozotocin diabetic rats. We studied the effect of long-term (4 months) administration of 1% myo-inositol supplement to the Cohen dia betic (type 2) rat on the development of nephropathy and renal Na+-K+- ATPase. This treatment reduced the increased renal Na+-K+-ATPase activ ity but had no effect on blood glucose levels, body weight, increased kidney weight, or creatinine clearance and did not prevent or reduce t he development of renal glomerular pathology. There was no correlation between the level of Na+-K+-ATPase activity and the degree of nephrop athy, It is possible that the renal pathological changes are due to me tabolic and humoral factors resulting from hyperglycaemia, other than myo-inositol depletion. The fact that myo-inositol treatment had no ef fect on the development of renal pathological changes but was shown to have a beneficial effect on restoring impaired conduction velocity an d on the disruption of structural elements in the nerve indicates that the effect of the biological changes ensuing from hyperglycaemia vary in different tissues depending on local conditions.