Effects of gonadal steroids on peripheral benzodiazepine receptor density in women with PMS and controls.

Abstract

GABA receptor-modifying neurosteroids may play a role in premenstrual syndrome (PMS). The peripheral benzodiazepine receptor (PBR) both regulates the formation of neurosteroids and is, in animals, regulated by ovarian steroids. Alterations in PBR density have been observed in association with several psychiatric disorders. We examined the effects of gonadal steroids on lymphocytic PBR density in nine women with prospectively confirmed PMS and nine controls. PBR densities were measured during three pharmacologically controlled conditions: gonadotropin releasing hormone agonist (Lupron)-induced hypogonadism, Lupron plus estradiol, and Lupron plus progesterone replacement. Blood samples were obtained after six weeks of Lupron alone and after 3-4 weeks of estradiol and progesterone replacement. No significant hormone state-related changes in PBR density were observed (ANOVA-R: phase-F(2,32)=1.5, P=0.2). Despite mood symptom development in the subjects with PMS, PBR density did not differ in women with PMS compared to controls across hormonal states (ANOVA-R: F(1,16)=0.6, P=0.4). PBR densities are not altered in women with PMS and are not changed significantly by selective gonadal steroid administration. Changes in PBR density would not appear to underlie the differential sensitivity to the mood destabilizing effects of ovarian steroids in PMS.