Modulation of peripheral benzodiazepine binding sites following chronic estradiol treatment.

A 10 day estradiol treatment of rats resulted in a marked reduction (43%) in peripheral benzodiazepine (BZ) binding sites in the testis and an up-regulation (27%) of these sites in the kidney. No significant alterations in brain central BZ receptors and heart peripheral binding sites were observed. The down-regulation of BZ binding sites in the testis may be related to or accompany estrogen-induced testicular atrophy. The physiological and pharmacological implications of the alterations obtained in the kidney are as yet unclear.