title: Androgen receptor-mediated regulation of adrenocortical activity in the sand rat, Psammomys obesus.
abstract: The wild sand rat, Psammomys obesus, displays seasonal variations in adrenocortical activity that parallel those of testicular activity, indicating functional cross-talk between the hypothalamo-pituitary-adrenal and hypothalamo-pituitary-gonadal axes. In the present study, we examined androgen receptor (AR)-mediated actions of testicular steroids in the regulation of adrenocortical function in the sand rat. Specifically, we examined the expression of AR in the adrenal cortex, as well as adrenal apoptosis in male sand rats that had been surgically castrated or castrated and supplemented with testosterone; biochemical indices of adrenocortical function and hormone profiles were also measured. Orchiectomy was followed by an increase in adrenocorticotropic hormone secretion from the anterior pituitary and subsequently, increased adrenocortical activity; the latter was evidenced by orchiectomy-induced increases in the adrenal content of cholesterol and lipids as well as adrenal hypertrophy (seen as an elevation of the RNA/DNA ratio). Further, androgen deprivation respectively up- and downregulated the incidence of apoptosis within the glucocorticoid-producing zona fasciculata and sex steroid-producing zona reticularis. Interestingly, orchiectomy resulted in increased expression of AR in the zona fasciculata. All of the orchiectomy-induced cellular and biochemical responses were reversible after testosterone substitution therapy. Together, these data suggest that adrenocortical activity in the sand rat is seasonally modulated by testicular androgens that act through AR located in the adrenal cortex itself.
authors.affiliation: Laboratoire de recherche sur les zones arides, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32, El-Alia, 16111, Algiers, Algeria.
authors.forename: Abdelouafi
authors.initials: A
authors.lastname: Benmouloud
authors.forename: Zaina
authors.initials: Z
authors.lastname: Amirat
authors.forename: Farida
authors.initials: F
authors.lastname: Khammar
authors.forename: Alexandre V
authors.initials: AV
authors.lastname: Patchev
authors.forename: Jean M
authors.initials: JM
authors.lastname: Exbrayat
authors.forename: Osborne F X
authors.initials: OF
authors.lastname: Almeida
mesh_terms: D000220:Adaptation, Biological / Q000502:physiology*; D000302:Adrenal Cortex / Q000166:cytology / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002784:Cholesterol / Q000378:metabolism; D005849:Gerbillinae / Q000378:metabolism / Q000502:physiology*; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D050356:Lipid Metabolism / Q000502:physiology; D008297:Male; D009919:Orchiectomy; D011944:Receptors, Androgen / Q000378:metabolism*; D012098:Reproduction / Q000502:physiology*; D012621:Seasons; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D012739:Gonadal Steroid Hormones; D011944:Receptors, Androgen; D013739:Testosterone; D002784:Cholesterol