Multiple steroid radioimmunoassays and automation. Versatile techniques for reproductive endocrinology

The combination of the efficient steroid-separating properties of a lipophilic Sephadex derivative Lipidex-5000sup(TM) and the use of antibodies with carefully selected specificity allows the quantitative determination of pregnenolone, progesterone, 17α-hydroxyprogesterone, androstenedione, testosterone, 5α-dihydrotestosterone, 5α-androstanedione, androsterone and 5α-androstane-3α, 17β-diol in 1- to 2-ml samples of both blood serum and amniotic fluid as well as in 300- to 600-mg pieces of prostatic tissue. The adaptation of the pipetting unit and incubator of a discrete clinical chemical analyser, System Olli 3000, for the automation of the radioimmunoassays has resulted in a greatly increased through-put and has decreased the experimental error of the procedure. In studies on reproductive endocrinology, the methodology developed has allowed the detection of a sex difference in androgen composition of the amniotic fluid early in pregnancy. Further, it is very likely that the decline in steroid production by the testis seen during the first year of life and then in senescence is affected by basically different mechanisms. There are also important differences in the steroid content of normal, hyperplastic and carcinomatous prostate. (author)