Protective Effects of Captopril in Radiation-Induced Renal Injury in Rats

ABSTRACT

The angiotensin I converting enzyme inhibitor (Captopril) has recently been studied extensively in various experimental models of radiation injury and has proven its protective effects in various organs, such as the lungs, gastrointestinal tract, and kidneys. Twenty-three Sprague-Dawley rats were divided into experimental and control group. The experimental group was divided into two large groups: the first one received a single dose of 18 Gy irradiation from an electron beam on the local field of the kidney region only, and the second group received captopril per oral continuously after the same doses of irradiation. The second experimental group was divided into four subgroups by captopril doses: 62.5 mg/l, 125 mg/l, 250 mg/l, and 500 mg/l, respectively. On light and electron microscopy, the kidneys of the irradiated rats with no captopril treatment showed diffuse glomerular contraction, congestion with occlusion and focal necrosis of the endothelial, and mesangial cells. The tubules showed ballooning degeneration, desquamation, and diffuse coagulation necrosis. Captopril treated rats, especially those given a high dose (more than 250 gm/l), revealed a marked reduction of the tubular and glomerular injuries. There was a statistically significant difference in the degree of renal injury among the experimental groups (p<0.05). The result of this study suggests that an administration of high dose captopril might prevent radiation-induced renal injury, especially in the early post-irradiation period.