Effects of 2-ethylhexanoic acid on reproduction and postnatal development in Wistar rats.

Reproductive toxicity of 2-ethylhexanoic acid (2-EHA) was studied in Wistar rats. The animals (24 animals per sex per group) were given 2-EHA as a sodium salt in drinking water at daily doses of 100, 300, or 600 mg/kg. Control animals received plain water. Male rats were exposed to 2-EHA for 10 weeks and females for 2 weeks prior to mating, both sexes during the mating period and females during the entire gestation and lactation period. 2-EHA caused a slight but dose-dependent decrease in fertility; time to mating increased at 300 and 600 mg/kg and even total infertility ensued. 2-EHA slightly decreased sperm quality in males. The spermatozoa were significantly less motile at 100 and 600 mg/kg and abnormal sperm occurred more frequently at the two highest dose levels. The average litter size was reduced by 16% in the dose group receiving 600 mg/kg. The birth weights of the pups were unaffected but the body weight gain was transiently slower during lactation at 600 mg/kg. Several pups appeared abnormal (kinky tail, lethargic, slightly paralyzed legs) and the physical development assessed by several landmarks (opening of eyes, eruption of teeth, hair growth) and reflexes (grip reflex, cliff avoidance) was delayed at 300 and 600 mg/kg. In another experiment, a single dose of 600 mg/kg 2-EHA was given to pregnant females by gavage on Gestational Day 4, 5, 6, or 7 and the number of implantations were counted on Gestational Day 10. Administration on Day 6 decreased the number of implantations and caused resorptions.(ABSTRACT TRUNCATED AT 250 WORDS)