Transcriptome profile of rat adrenal evoked by gonadectomy and testosterone or estradiol replacement

Sex differences in rat adrenal cortex are manifested as larger adrenal volume of cortex and higher corticosterone secretion by females compared with males. The molecular bases of these sex related differences are poorly understood. Therefore we performed microarray studies to demonstrate the effect of testosterone and estradiol on the expression of differentially regulated genes in rat adrenal gland. Experiment was performed on adult male and female Wistar rats (12-week-old; body weight: 120-150 g). Rats were gonadectomized or sham operated. Orchiectomy (ORX) was performed via scrotal access while ovariectomy (OVX) by two dorso-lateral incisions. Fourteen days after surgery half of ORX rats was replaced with testosterone (s.c. injection of Testoviron-Depot, Schering AG, Berlin, 5 mg/100 g body weight) while half of OVX animals with estradiol (s.c. injection of Estradiol-Depot, Jenapharm, 0.5 mg/100 g body weight). After 2 weeks (4 weeks post surgery) rats were decapitated. Adrenal glands were collected for RNA extraction and hybridization on Affymetrix microarrays.