Human Testis Tissue Research Articles

Steroid metabolism in human and boar testis tissue. Steroid concentrations and the position of the sulfate group in steroid sulfates

The steroid composition of and steroid conjugation in human cadaver and boar testes were investigated by analyzing the endogenous steroids. Gas-liquid chromatography and gas chromatography-mass spectrometry were used to identify the steroids and to determine the position of the sulfate group in sulfate conjugates. For the latter purpose, the steroids were first acetylated and subsequently solvolyzed and converted to trimethylsilyl ethers. In addition to the compounds previously identified as endogenous components, human testis was also found to contain progesterone, 17 α -hydroxyprogesterone and 20 α -hydroxy-4-pregnen-3-one in the free steroid fraction and 3 β -hydroxy-17 α -5-pregnen-20-one in the monosulfate fraction.

Evaluation of a radioimmunoassay for testosterone estimation

A radioimmunoassay technique, which is essentially a modification of the method described by Furuyama et al.[1], has been evaluated for the determination of testosterone in human peripheral plasma and rat testis tissue. The antiserum used was raised against testosterone-3-(0-carboxymethyl)-oxime-bovine serum albumin in female rabbits. It had an association constant of 5.5 × 10 9 1/mol, 4°C, at a dilution of 1 in 20,000. The procedure involved addition of [ 3H]-testosterone internal standard, extraction and chromatography of the plasma extracts on alumina micro-columns prior to assay. Testis tissue extracts were not chromatographed. Known amounts of standard testosterone were subjected to the same procedures. After incubation with antiserum for 16 h at 4°C total recovery from the extraction, chromatography (when used) and incubation procedures were measured in order to correct for losses. Either toluene scintillation fluid, dextran-coated charcoal or polyethylene glycol were used to separate free and bound testosterone. For human plasma as well as for testis tissue a good correlation was observed between results obtained with radioimmunoassay and a gas chromatographic method using electron capture detection of testosterone chloroacetate[12].

Free and sulphate-conjugated 16-unsaturated C 19 steroids in human testis tissue

Free and monosulphated 5α-androst-16-en-3α-ol, 5α-androst-16-en-3β-ol and 5,16-androstadien-3β-ol were identified and quantified in human cadaver testis tissue. Free and monosulphated steroid fractions were isolated by Sephadex LH-20 chromatography. Further separation and purification of the 16-unsaturated C 19 steroids was achieved using silicic acid and hydroxyalkoxypropyl Sephadex chromatography. The steroids were finally identified by gas-liquid chromatography and gas chromatography-mass spectrometry. In the free steroid fraction the relative abundance of the 16-unsaturated C 19 steroids was 5α-androst-16-en-3β-ol > 5,16-androstadien-3β-ol > 5α-androst-16-en -3α-ol and in the monosulphate fraction 5,16-androstadien-3β-ol > 5α-androst-16-en-3β-ol > 5a-androst-16-en-3α-ol.

Free and sulfate-conjugated neutral steroids in human testis tissue.

Free and sulfate-conjugated neutral steroids in human testis tissue.

Metabolism of C 18 and C 19 steroids by testis tissue

Incubation of rat testis tissue with labeled estrone resulted in the conversion of the substrate to estradiol-17β and a metabolite which had the chemical and chromatographic characteristics of 6α-hydroxy-estradiol-17β. Human testis tissue converted estrone to estradiol-17β and two other metabolites with the characteristics of 6-keto-estradiol-17β and 6α-hydroxy-estradiol-17β. Formation of 6α-hydroxy-estradiol-17β by rat testis tissue increased proportionally to the duration of incubation. Rat testis tissue in vitro exhibited a greater affinity towards uptake of estrone than of androst-4-ene-3,17-dione. Formation of testosterone from androst-4-ene-3,17-dione in the in vitro system was more rapid than the conversion of estrone to estradiol-17β.

Inhibition of 16α-hydroxylation in human testis tissue by SU-9055

Testis tissue obtained from a patient with a feminizing syndrome was incubated with 1μC progesterone-4-C 14 and 10 −4 M SU-9055. The conversions of labeled progesterone to 17α-hydroxyprogesterone, testosterone, and 16α-hydroxy-progesterone observed in control incubations were inhibited in the presence of the SU-9055. This is the first demonstration of inhibition of 16α-hydroxylation by SU-9055.

Formation of steroid hormones from acetate-1- 14C by a human fetal testis preparation grown in organ culture

Human fetal testis tissue was shown to synthesize in vitro steroid hormones from sodium acetate-1- 14C. Testes obtained 13 hours after death from a 21 cm male human fetus were grown in organ culture. After 9 days sodium acetate-1- 14C was added, and growth was permitted to continue for 8 more days. Radioactive steroids formed were identified by reverse isotope dilution, and radiochemical purity was established by crystallization to constant specific activity. The C 21 steroids, 3 β-hydroxy- Δ 5-pregnen-20-one, progesterone, and 17-hydroxy- Δ 4-pregnene-3, 20-dione, were the major radioactive steroids found. The c 19 steroids, Δ 4-androstene-3, 17-dione and testosterone, were formed in smaller amounts.