Effects of neonatal chlordecone exposure on pituitary-adrenal function in adult Fischer-344 rats

Abstract

Fischer-344 rat pups of either sex were injected on day four of age with 1 mg/pup chlordecone (CLD) or DMSO vehicle. At 77-78 days of age, the rats were subjected to a repeated stress-induced analgesia (SIA) paradigm. A white noise (conditioned stimulus; CS) was paired with scrambled footshock for approximately one-half of the rats, while the remaining rats were exposed to the CS only. Conditioning occurred over a seven day period, one trial per day. On day 8 all rats received the CS only; 15 min later, the rats were sacrificed and serum and adrenals collected for corticosterone and/or prolactin measurements. Although prior neonatal exposure to CLD had no effect on the acquisition of the conditioned response or the responsiveness of the adrenocortical system to the CS, basal levels of serum and adrenal corticosterone were generally depressed in CLD-exposed males. Basal serum prolactin levels were decreased and increased in CLD-exposed males and females, respectively. These data suggest that neonatal CLD exposure may serve as a chemical stressor that produces long-lasting alterations in basal pituitary-adrenocortical function. The expression of these effects also appeared to be sex-dependent.