Impact of pregnancy and lactation on GABA(A) receptor and central-type and peripheral-type benzodiazepine receptors.

The effect of pregnancy and lactation on GABA(A) receptor and central- and peripheral-type benzodiazepine receptors (CBR and PBR, respectively) was studied in female Sprague-Dawley rats. Pregnancy was associated with increased CBR density (on day 19) in the hippocampus and with decreased [3H]Ro 15-1788-specific binding in the hypothalamus during pregnancy and lactation. A similar decrease in [3H]PK 11195-specific binding was observed in the hypothalamus and pituitary. An increase in PBR density in the ovary and uterus was observed during pregnancy, while adrenal PBR density was down-regulated during pregnancy and lactation. It seems that the hormonal changes occurring during pregnancy and lactation play a role in the regulation of CBR and PBR in discrete tissues.