TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1002. HEALTH EFFECTSspermatocytes (high dose, intermediate dose) and stage-7 spermatid (high and intermediate doses) countswere significantly reduced and were treatment related. Testicular activity of succinic dehydrogenase wassignificantly lowered in the two high-dose groups, testicular cholesterol concentrations were elevated inthe highest-dosed group, and both serum testosterone and testicular levels of 3β-∆ 5 -hydroxysteroiddehydrogenase were significantly lowered. The authors also determined that the total testicular levels ofascorbic acid in the two higher-dosing groups was about twice that of the control values whereas, in thehighest-treated group the total ascorbic acid levels were about half those of controls. At the low dose(20 mg/kg/day), testicular protein, 3β-∆ 5 -hydroxysteroid dehydrogenase, and serum testosterone weredecreased. The authors indicated that chromium enhanced levels of the vitamin, but at the highest dosetesticular levels became exhausted, thus decreasing the ability of the cells to reduce chromium(VI).Significant alterations in sexual behavior and aggressive behavior were observed in male Sprague-Dawleyrats exposed to 42 mg chromium(VI)/kg/day as potassium dichromate in the drinking water for 12 weeks(Bataineh et al. 1997). The alterations in sexual behavior included decreased number of mounts, lowerpercentage of ejaculating males, and increased ejaculatory latency and post-ejaculatory interval. Theadverse effects on aggressive behavior included significant decreases in the number of lateralizations,boxing bouts, and fights with the stud male and ventral presenting. No significant alterations in fertilitywere observed when the exposed males were mated with unexposed females.Mice exposed for 7 weeks to 15.2 mg chromium(VI)/kg/day as potassium dichromate in the diet hadreduced sperm count and degeneration of the outer cellular layer of the seminiferous tubules.Morphologically altered sperm occurred in mice given diets providing 28 mg chromium(VI)/kg/day aspotassium dichromate (Zahid et al. 1990). No effect was found on testis or epididymis weight, andreproduction function was not assessed. In contrast, an increase in testes weight was observed in miceexposed to 6 mg chromium(VI)/kg/day as potassium dichromate for 12 weeks. At the next highest dose(14 mg chromium(VI)/kg/day), decreases in seminal vesicle and preputial gland weights were observed(Elbetieha and Al-Hamood 1997). In studies designed to confirm or refute the findings of the Zahid et al.(1990) study, the reproductive effects of different concentrations of chromium(VI) as potassiumdichromate in the diet on BALB/c mice and Sprague-Dawley rats were investigated (NTP 1996a, 1996b).Groups of 24 males and 48 females of each species were fed potassium dichromate(VI) in their feedcontinuously for 9 weeks followed by an 8-week recovery period. For mice, the average daily ingestionsof chromium(VI) were 1.05, 3.5, 7.5, and 32.2 mg/kg/day for males and 1.8, 5.7, 12.0, and 48 mg/kg/dayfor females. For rats, the average daily ingestions of chromium(VI) were 0.35, 1.05, 2.1, and8.4 mg/kg/day for males and 0.35, 1.05, 2.45, and 9.8 mg/kg/day for females (NTP 1996b). Microscopic