Vitamin C supplementation during chronic variable stress exposure modulates contractile functions of testicular artery and sperm parameters in male Wistar rats

Abstract

Abstract Background Humans are exposed to identifiable multiple environmental stressors. However, there is paucity of studies assessing chronic variable stress (CVS) exposure together with antioxidant supplementation on reproductive function. This study investigates impact of vitamin C supplementation, during CVS exposure on contractile functions of testicular artery and sperm parameters. Twenty pubertal male Wistar rats (150–200 g) were grouped into four of five rats each consisting of control (normal saline), vitamin C treated (7 mg/kg bwt), chronic variable stress (CVS) + vitamin C, and CVS only. Animals were treated respectively for 8 weeks. Serum superoxide dismutase (SOD), catalase, malondialdehyde (MDA) activity, testosterone, and cortisol were assayed. Contractile responses of excised testicular artery to phenylephrine, potassium chloride, acetylcholine, and sodium nitroprusside were determined using Ugo Basile data acquisition system. Sperm parameters and histopathology of the testis were also determined. Statistical significance was taken at p < 0.05 Result MDA activity was significantly increased in group exposed to chronic variable stress. However, groups supplemented with vitamin C during CVS exposure showed no significant increase. Serum SOD and catalase were enhanced in group exposed to CVS with vitamin C supplementation when compared to group exposed to chronic variable stress only. Chronic variable stress exposure increased serum cortisol level and this was attenuated with vitamin C supplementation. Vitamin C supplementation significantly increased serum testosterone level when compared to CVS only exposed group. Contraction responses of testicular arterial strips to phenylephrine and potassium chloride were attenuated in vitamin C supplemented groups when compared to CVS only exposed group. Vitamin C supplementation during CVS exposure also enhanced relaxation of testicular artery strip to sodium nitroprusside and acetylcholine. Sperm count and percentage motility were significantly reduced in CVS only exposed group when compared vitamin C supplemented group. Sperms cells with abnormal morphology were also significantly increased in chronic variable stress only exposed group when compared to control and vitamin C supplemented groups. Conclusion Chronic variable stress adversely impacts contractility of testicular artery, sperm parameters, cortisol, and testosterone level. Vitamin C supplementation modulated these by suppressing MDA and enhancing antioxidant enzyme activity.

Keywords

• Testicular artery
• Chronic variable stress
• Vitamin C
• Sperm parameters
• Modulation