Exposure to threshold doses of nicotine in utero: III. Augmentation of the prolactin and ACTH response to 8-OH DPAT by desipramine treatment is compromised in adult male offspring.

Gravid female rats were injected subcutaneously with saline (SAL) or nicotine (3.0 mg/kg and 0.05 mg/kg, bid) from days 14-21 of gestation. Adult 105-day old male offspring from each of the three groups were treated daily with saline or desipramine (DMI) (10 mg/kg, sc) for 14 days. Twenty-four hours after the last injection, animals were challenged with saline or 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH DPAT) (0.1 mg/kg, sc), a serotonin IA(5-HT(IA)) agonist, and plasma prolactin and ACTH concentrations were measured 15 minutes later. DMI treatment augmented both the prolactin and ACTH responses to 8-OH DPAT in the SAL controls. Neither the prolactin nor the ACTH response was augmented significantly in the animals exposed prenatally to either nicotine dosage regimen, although there was a strong trend for the augmentation to occur in the low-dose nicotine exposed animals. The results indicate the capacity of 5-HT systems to adapt normally to DMI administration, as manifested by neuroendocrine responsivity to 8-OH DPAT, was compromised in adult animals exposed to nicotine in utero.