Effect of Pinealectomy and Blindness on Alcohol Induced Testicular Injury

Abstract

Background: In the Sprague-Dawley rat, bilateral blindness and pinealectomy may affect testicular physiology. Though ethanol is a well known testicular toxicant causing part of its damage through increased lipid Peroxidation, it is not known how the testis in blind or pinealectomized rats will respond to alcohol exposure.

Objective: An experiment was carried out to investigate the effect of ethanol on the testicular lipid Peroxidation and semen parameters in pinealectomized and blind rats.

Materials and methods: Seventy adult male Sprague-Dawley rats weighing between 180-200g were divided into six groups. Group 1(n=10) were intact animals given 1.5ml of normal saline twice per week; group II (n=12) had 2g/kg body weight of 7.5% ethanol orally twice per week. Groups III (n=12) and IV (n=12) had unilateral (left side) and bilateral optic enucleation respectively under sodium pentothal anaesthesia. Twenty-four hours after operation, the rats were commenced on the same dose of ethanol. Groups V and VI (n=12) had sham pinealectomy and pinealectomy respectively and in addition given the same dose of ethanol. After 6 weeks, animals were sacrificed by decapitation and testes collected for estimation of testicular weight, sperm count, sperm motility, testicular malondialdehyde (MDA) and histology.

Results: There was a significant decrease in testicular weight, sperm count and motility in all groups compared to the control (p<0.05). Sperm count and motility were significantly less in the bilaterally blinded than in in the unilaterally blinded ethanol treated rats, and the bilaterally blinded ethanol treated rats had significantly less MDA than the unilaterally blinded ethanol treated rats. There was no significant difference in MDA levels between intact ethanol treated, the unilaterally blinded ethanol treated, and the sham pinealectomized ethanol treated rats. The pinealectomized ethanol treated rats had significantly higher MDA than all other groups.
Conclusion: Bilateral but not unilateral blindness reduces sperm count, sperm motility and testicular lipid peroxidation following ethanol exposure. Whereas pinealectomy increases testicular lipid peroxidation, and decreases sperm count and motility following ethanol exposure in rats.


Keywords: Pineal gland, Pinealectomy, Blindness, Malondialdehyde, Lipid Peroxidation

NQJHM Vol. 16 (3) 2006: pp. 97-101