Androgen receptor in the Harderian gland of Rana esculenta.
An androgen receptor has been identified in the cytosolic and nuclear extracts of the Harderian gland of the frog, Rana esculenta. A single class of high-affinity binding sites was found: Kd = 1.9 +/- 1.3 (S.D.) nmol/l (n = 26) for the cytosolic extract and Kd = 0.9 +/- 0.8 nmol/l (n = 15) for the nuclear extract. The presence of binding activity in both nuclear and cytosolic extracts and the low rate of ligand-receptor dissociation are characteristics that distinguish this receptor from a steroid-binding protein. The Kd did not show any sex difference and did not exhibit any secretory activity-related change. Binding in both cytosolic and nuclear extracts was specific for androgens (testosterone = 5 alpha-dihydrotestosterone); oestradiol-17 beta showed a 30% cross-reaction; moreover, specific binding of [3H]oestradiol-17 beta was not detectable. The binding capacity of the Harderian gland increased progressively in both fractions from October to December, reaching a peak in May, and decreased suddenly during July to August. The lack of any morphological sex-related difference in the Harderian gland of the green frog might be accounted for by the high amount of circulating androgens as well as a similar concentration of androgen receptor in both sexes.
d'Istria
M
M
Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate F. Bottazzi, Faculty of Medicine, University of Naples, Italy.
Chieffi-Baccari
G
G
Di Matteo
L
L
Minucci
S
S
Varriale
B
B
Chieffi
G
G
D000818:Animals; D001667:Binding, Competitive; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005260:Female; D006243:Harderian Gland / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011893:Rana esculenta / Q000378:metabolism*; D011944:Receptors, Androgen / Q000032:analysis*; D012621:Seasons; D013739:Testosterone / Q000378:metabolism
D011944:Receptors, Androgen; D013739:Testosterone