Effect of treatment with captopril, an angiotensin converting enzyme inhibitor, and HET0016, a 20-HETE inhibitor, and their combination on renal complications of diabetes in Sprague Dawley rats -

Abstract

Background: Diabetic nephropathy is one of the major life threatening complications of diabetes mellitus. It is characterized by renal hypertrophy, increased extracellular matrix deposition, increased albumin excretion which will all eventually lead to kidney failure. Administering captopril, an angiotensin converting enzyme inhibitor, will slow down all these processes and delay the onset of nephropathy. Recent studies have shown that 20-HETE, an arachidonic acid metabolite of cytochrome P450 of the 4A family, plays a role in the pathology of diabetic nephropathy and does so not only through its vasoconstrictor properties but through the production of reactive oxygen species (ROS) which mediate the renal damage. N-hydroxy-N-(4-butyl-2 methylphenyl) formamidine (HET0016) is a potent inhibitor of 20-HETE synthesis and is thought to decrease the production of ROS, leading to a renoprotective effect.Aim: The present study aims to determine the role of 20-HETE in renal hypertrophy, extracellular matrix deposition and ROS production in a model of diabetes. In addition, the effect of combined administration of captopril and HET0016 on inhibiting the production of 20-HETE and the related outcomes of diabetes, such as ROS production and indexes of kidney injury, will be studied in order to determine if the combined treatment has a positive therapeutic outcome on renal dysfunction.Methods: Male Sprague-Dawley rats were used in this experiment as animal model. Diabetes was induced using streptozotocin in order to mimic type I diabetes. Rats were then divided into eight groups according to the different treatment they received. Control and diabetic vehicle rats were treated with either normal saline, captopril, HET016 or with a combination of captopril and HET0016. Body weight, blood glucose levels, urine volume, were taken on day 0, day 14 and day 28. On day 28, rats were sacrificed and the kidneys were harvested. Plasma collected on day 28 was used to assess 20-HETE levels in the circulation. Kidney cortex were isolated