ANDROGEN RECEPTOR LEVELS IN PREPUTIAL SKIN FROM BOYS WITH HYPOSPADIAS

The levels of high affinity, low capacity binding of [3H]methyltrienolone [17β-hydroxy-17a-methyl-estra-4, 9, lltriene- 3-one ([3H]MT)] to human preputial skin cytosol in 11 patients with hypospadias and 16 control subjects have been measured. [3H]MT has been shown to have a specific affinity to a high affinity, low capacity protein similar to the androgen receptor found on other tissues. The binding component was found to be heat labile and was totally destroyed by trypsin. The time of dissociation and degradation at 0 C of the [3H]MTreceptor complex was found to be slow (U/2, 64 and 74 h, respectively). The [3H]MT-receptor complex had an isoelectric point at about pH 5.2. 5α-Dihydrotestosterone (17β-hydroxy- 5a-androstan-3-one) and testosterone were found to displace [3H]MT from the receptor, whereas androstendione, progesterone, estradiol, and the synthetic progestin R5020 (17α, 21- dimethyl-19-nor-pregna-4, 9-diene-3, 20-dione) were much less effective competitors. Cortisol did not displace [3H]MT. The dissociation constant of the [3H]MT-receptor complex varied between 1.7-21.7 nM, and the number of binding sites ranged from 1.08-11.36 fmol/mg protein. The mean value for the amount of androgen receptor in cytosol of preputial skin from 11 boys with different types of hypospadias was lower (4.01 fmol/mg protein) than that in 16 healthy controls (6.46 fmol/mg protein; P < 0.05). Four subjects showed receptor levels that were lower than the range of the controls. © 1979 by The Endocrine Society.