Histological study on the toxic effect of 2-bromopropane on the seminiferous tubules of adult male albino rats

ABSTRACT

2-Bromopropane [2-BP] is a haloalkane used in industry as an alternative to ozone layer depleting solvents. It has recently been suspected to be a causative agent for some reproductive dysfunctions in both male and female workers exposed to it in electronic factories. The study was carried out to evaluate the possible toxic effects of 2-BP administration on the seminiferous tubules [S. Ts] of rat testis, and its potential reversibility after 2-BP withdrawal. The study was conducted on 30 adult male albino rats weighing from 100-150g each. They were categorized into 3 equal groups. Group I served as a control group. Group II rats received daily subcutaneous injection of 2-BP [400 mg/kg b.w.] for 28 days. Group III rats received 2-BP in the same dose and for the same duration as group II followed by a further 28-day recovery period. At the end of experiment, blood samples were collected to detect testosterone levels, and the rat testes were weighed and examined for the daily sperm production. Specimens were taken from the testes of all animals and subjected to both light and electron microscopic examinations. 2-BP administration [in group II] significantly decreased absolute testicular weight and daily sperm production as well as serum testosterone levels. Histologically, atrophy of the S.Ts accompanied by interstitial oedema was evident. Moderate to severe degenerative changes involving all types of spermatogenic cells, including spermatogonia, were also demonstrated. Furthermore, Leydig cells depicted ultrastructural evidence of decreased activity. After a 4-week recovery period [group III], mild increase in serum testosterone levels as well as other laboratory parameters were noticed. However, they were still much less as compared to the control. Histologically, only limited amelioration of the testicular lesions in the germinal epithelium as well as Leydig cells was revealed. Such persistent lesions were attributed to the damaging effect of 2-BP on testicular stem cells; spermatogonia. The study demonstrates vulnerability of the testicular tissue to 2-BP intoxication. Therefore, careful consumption of 2-BP containing solvents and pharmaceuticals is necessary