Evidence for an androgen receptor in porcine Leydig cells

Abstract

Cytosol and nuclear androgen receptor concentrations were measured in freshly prepared and cultured Leydig cells of immature pig testis with exchange assays using [3H]methyltrienolone as labelled ligand. Androgen receptors in Leydig cells had high affinity for [3H]methyltrienolone and steroid binding specificity typical of an androgen receptor. The mean receptor concentrations were 76 fmol/mg protein and 210 fmol/mg DNA for cytosol and nuclei, respectively. In sucrose gradients, cytosol androgen receptors sedimented in the 4 S region. The cells maintained androgen receptors under culture conditions. Exposure of cultured cells to [3H]methyltrienolone (10 nmol/l) resulted in accumulation of androgen receptors in the nuclei with maximal uptake by 1 h. We conclude that methyltrienolone binding sites with characteristics of androgen receptors were identified in both cytosol and nuclei of porcine Leydig cells.Androgen receptors have been detected in the rat testis and also in human testicular tissue. Using various biochemical techniques, androgen recep¬ tors have been found in whole testis (Hansson et al. 1974;Mulder et al. 1975), seminiferous tubules Trivial names and systematic names of steroids and abbreviations are: -hydroxy-17ct-methyl-4,9,11-oestratrien-3-one; ORG 2058: 16a-ethyl-21-hydroxy-19-nor-4-pregnene-3,20-dione; DES: diethylstilboestrol, 3,4-bis(p-hydroxyphenyl)-3-hexene; dexamethasone : 9a-fluoro-1 Iß, 17a,21-trihydroxy16a-methyl-1.4-pregnadiene-3,20-dione; DCC : dextran coated charcoal ;EgTA: ethylene glycol-bis-(ß-aminoethylether)-, , ', '-tetra-acetic acid;

Bovine Uterine, Cervical and Ovarian Androgen Receptor Concentrations

“…1979, Ekman et at. 1982, Isomaa et al 1987, Muechler 1987. In our study, RBAs to bovine uterine ARC are similar to those reported above in various mammalian tissues.…”

“…5a-DHT bound with higher affinity to ARC than did testosterone in bovine and human uterine tissue (de Boer et al 1986, Muechler 1987, in rat (Gaubert et al 1980) and human prostatic cytosol (Ekman et at. 1982) but not in porcine Ley dig cells (Isomaa et at. 1987).…”

“…The relative binding affinities (RBAs) of various steroidal ligands to mammalian ARC differ to some degree according to the tissue source of receptor. Methyltrienolone (R1881) has a higher affinity to ARC than the endogenous androgens 5a-DHT and testosterone, in human (Ekman et al 1982) and rat prostatic cytosol (Bonne & Raynaud 1976, Gaubert et al 1980, in porcine Leydig cells (Isomaa et al 1987) and in calf uterus (de Boer et al 1986). 5a-DHT bound with higher affinity to ARC than did testosterone in bovine and human uterine tissue (de Boer et al 1986, Muechler 1987, in rat (Gaubert et al 1980) and human prostatic cytosol (Ekman et at.…”