The Role of Free Radical in the Pathogenesis of Impotence in Streptozotocin-Induced Diabetic Rats.
10.3349/ymj.2003.44.2.236
- Author:
Ji Kan RYU
1
;
Dae Joong KIM
;
Taek LEE
;
Yun Seog KANG
;
Sang Min YOON
;
Jun Kyu SUH
Author Information
1. Department of Urology, Inha University College of Medicine, Incheon, Korea. jksuh@inha.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Diabetes mellitus;
erection;
free radical;
rat
- MeSH:
Animals;
Diabetes Mellitus, Experimental/*complications/metabolism;
Diabetes Mellitus, Type II/*complications;
Female;
*Free Radicals;
Glutathione/analysis;
Impotence/*etiology;
Lipid Peroxidation;
Male;
Rats;
Rats, Sprague-Dawley;
Streptozocin;
Support, Non-U.S. Gov't
- From:Yonsei Medical Journal
2003;44(2):236-241
- CountryRepublic of Korea
- Language:English
-
Abstract:
Diabetes is the most common cause of erectile dysfunction (ED). Oxidative stress has been suggested to be a contributory factor in vascular complications of diabetes in various organs. In the present study, we investigated whether oxidative stress is associated with erectile function in non- insulin dependant diabetes mellitus (NIDDM) rats. Fifty-four Sprague-Dawley rats were the subjects of this study. In each rat, NIDDM was induced by an intraperitoneal injection of 90mg/Kg of streptozotocin on the second day after birth. Based on the diabetic period, they were classified into either short-term or long-term diabetics (avg. 22 weeks, n=18 and avg. 38 weeks, n=20), respectively, and their age-matched controls (n=16). To evaluate the erectile function in each rat, the intracavernous pressure, and latency to maximal pressure, following cavernous nerve stimulation (frequency: 1 Hz, intensity: 3 - 6 V, pulse width: 1 msec, pulse duration: 1 min.) was analyzed. To evaluate both oxidative stress from reactive oxygen species, and antioxidant function as a defense against them, total malondialdehyde and glutathione levels were measured in the corpus cavernosum of the penis, using a spectrophotometric assay. The intracavernous pressure following cavernous nerve stimulation was significantly lower in the long-term (49.8 +/- 9.4 cmH2O) than the short-term diabetics (75.9 +/- 14.8 cm H2O), and markedly decreased in the diabetic rats, compared with their age-matched controls (long-term controls; 60.7 +/- 17.2 cmH2O, short-term controls; 95.2 +/- 20.4 cmH2O). The malondialdehyde content in the corpus cavernosum was markedly increased in the diabetics (2.13 +/- 0.27 nM/mg protein) compared to the controls (1.48 +/- 0.22 nM/mg protein). Furthermore, the glutathione level was significantly decreased in the diabetics, compared to age-matched controls (short-term control; 218.3 +/- 25.6 microM/mg protein, long-term control; 150.2 +/- 9.8 microM/mg protein). In the diabetic groups, it was more significantly decreased in the long-term diabetics (134.8 +/- 11.3 microM/mg protein) than in short-term diabetics (182.1 +/- 18.8 microM/mg protein). NIDDM causes erectile dysfunction, which slowly progresses. Oxidative stress to cavernous tissue may be a contributory factor in erectile dysfunction in diabetics.
