Fertility and developmental neurotoxicity effects of inhaled hydrogen sulfide in Sprague-Dawley rats

In this study, we examined whether perinatal exposure by inhalation to hydr ogen sulfide (HPS) had an adverse impact on pregnancy outcomes, offspring p renatal and postnatal development, or offspring behavior. Virgin male and f emale Sprague-Dawley rats (12 rats/sex/concentration) were exposed (0, 10, 30, or 80 ppm H2S; 6 h/day, 7 days/week) for 2 weeks prior to breeding. Exp osures continued during a 2-week mating period (evidence of copulation = ge station day 0 = GD 0) and then from GD 0 through GD 19. Exposure of dams an d their pups (eight rats/litter after culling) resumed between postnatal da y (PND) 5 and 18. Adult male rats were exposed for 70 consecutive days. Off spring were evaluated using motor activity (PND 13, 17, 21, and 60 +/- 2), passive avoidance (PND 22 +/- 1 and 62 +/- 3), functional observation batte ry (PND 60 +/- 2), acoustic startle response (PND 21 and 62 +/- 3), and neu ropathology (PND 23 +/- 2 and 61 +/- 2). There were no deaths and no advers e physical signs observed in F-0 male or female rats during the study. A st atistically significant decrease in feed consumption was observed in F-0 ma le rats from the 80-ppm H2S exposure group during the first week of exposur e. There were no statistically significant effects on the reproductive perf ormance of the F-0 rats as assessed by the number of females with live pups , litter size, average length of gestation, and the average number of impla nts per pregnant female. Exposure to H2S did not affect pup growth, develop ment, or performance on any of the behavioral tests. The results of our stu dy suggest that H2S is neither a reproductive toxicant nor a behavioral dev elopmental neurotoxicant in the rat at occupationally relevant exposure con centrations (less than or equal to 10 ppm). (C) 1999 Elsevier Science Inc. All rights reserved.