Histomorphological Effects of Oral Nicotine Administration on the Testes of Adult Wistar Rats

Abstract

Nicotine is a potent para-sympathomimetic alkaloid, which belongs to the Nightshade family of plants and is abundant in the roots and leaves of these plants.  Here, we investigated the histomorphological effects of oral nicotine exposure on the testes of adult Wistar rats. Sixteen adult male Wistar rats were divided into 4 groups (I, II, III, and IV), with each group containing 4 rats per group. Control group (I) received growers mash with water, group II received 2mg kg^-1 day^-1 of nicotine, group III received 4 mg kg^-1 day^-1 of nicotine and group IV received 6 mg kg^-1 day^-1 of nicotine via the oral route of administration, in addition to food and water for six weeks. At the end of the 7^th, 21^st, and 42^nd days of the administration, animals were euthanized by cervical dislocation, and testes were harvested and processed with standard histological techniques. Euthanizing on these various days was done to assess the time and dose-dependent effect of nicotine on the testes. Findings from histological observation of the testes showed similar histoarchitectural changes on different days between the treated groups and the control group. These changes may be attributed to the drug metabolism of nicotine, administration route of nicotine, and drug dosage adopted in the current study.  However experimental animals administered with nicotine for 42 days, showed normal histology of the testes with the presence of vascular congestion in the lumen of the seminiferous tubules. Within the limitation and design of this study, oral nicotine exposure at a low dose showed no features of testicular toxicity as there were no histoarchitectural distortions in the treated animals. However, our findings suggest that nicotine exposure at a low dose may possess a therapeutic effect in the management of testicular pathologies.