ABSTRACT
Thiodiglycol (TDG) is the main product of sulfur mustard hydrolysis and is an environmental contaminant. Subacute and subchronic oral toxicity studies with TDG were conducted in Sprague-Dawley rats. Neat TDG was administered by gavage at doses of 157, 313, 625, 1250, 2500, 5000, and 9999 mg/kg/d, 5 days per week, for 14 days. In the 14-day study, decreased body weight and food consumption were observed at 5000 mg/kg/d. In the 90-day study, rats received neat TDG at doses of 50, 500, or 5000 mg/kg/d for 5 days per week. A fourth group served as a sham control. Individual body weight and food consumption were measured weekly. At termination of the experiment, urine, blood, and tissue samples were collected. Rats displayed significant decreased body weight with no effect on food consumption following administration of TDG at 5000 mg/kg/d. Both male and female rats showed significant increased kidney weights at 5000 mg/kg/d. The organ to body weight ratios increased significantly for liver, kidneys, testes, and brain in males and adrenals in females for 5000 mg/kg/d. At all doses of TDG, hematological and clinical parameters and tissue histopathology remained unaltered. The no observed adverse effect level (NOAEL) for oral subchronic toxicity was 500 mg/kg/d. Benchmark dose (BMD) was derived from the decreased gain in body weight that was seen in male rats. A BMD based on a 10% decrease in body weight was 1704 mg/kg/d, and the lower confidence limit on the dose BMD, the BMDL, was 372 mg/kg/d.
Subject(s)
Chemical Warfare Agents/toxicity , Sulfhydryl Compounds/toxicity , Administration, Oral , Animals , Benchmarking , Blood Cell Count , Blood Chemical Analysis , Body Weight/drug effects , Eating/drug effects , Female , Lethal Dose 50 , Male , No-Observed-Adverse-Effect Level , Organ Size/drug effects , Rats , Rats, Sprague-Dawley , Sex CharacteristicsABSTRACT
Thiodiglycol (TG), a hydrolysis product of sulfur mustard (HD), is a potential contaminant of soil and water at certain military sites. To establish developmental toxicity criteria for TG, an oral developmental toxicity study was conducted in Sprague-Dawley rats. Neat thiodiglycol (99.9 %) was administered orally to mated female rats from gestation days (GDs) 5 through 19. The day of positive mating was considered day 0. A pilot study was conducted with TG at dose levels 250, 500, 1,000, 2,000, or 5,000 mg/kg to select suitable doses for the main study. In the main study, three groups of rats (25/group) received TG by gavage at dose levels of 430, 1,290, or 3,870 mg/kg/day. A fourth group served as a sham control. On day 20 of gestation, all females were euthanized and a cesarean section performed. Litters were examined for soft tissue and skeletal alterations. Maternal toxicity was limited to dams receiving TG at 3,870 mg/kg/day. At this dose, body weights and food consumption were reduced during certain periods of gestation. Fetuses derived from those dams exhibited a nonstatistically significant increased incidence of variations when compared to controls. Fetal body weights in the 3,870 mg/kg/day group were significantly lower than controls. There was no increased incidence of anomalies when thiodiglycol-treated fetuses were compared to controls. It was concluded that TG did not produce terata. Developmental toxicity (decreased fetal weights and associated delays in development) occurred only at the maternally toxic dose of 3,870 mg/kg. It appears that 1,290 mg/kg/day could be considered no observed adverse effect level (NOAEL) for oral developmental toxicity. The lowest observed adverse effect level (LOAEL) was 3,870 mg/kg for maternal toxicity.
