Glycosidases in human semen and male genital organs

PSA forms complexes with α1-antichymotrypsin in prostate

BACKGROUND

PSA is the most useful prostate cancer marker. However, its levels are increased also in some non-malignant conditions. In circulation, the majority of PSA is complexed with protease inhibitors, including α(1) -antichymotrypsin (ACT). The proportion of the PSA-ACT complex is higher in patients with prostate cancer than in controls without cancer. The expression of ACT has been shown to be higher in prostate cancer than in benign prostatic hyperplasia. However, results regarding the extent which PSA forms complexes within the prostate and whether there are differences in complex formation between normal and malignant prostatic tissue are inconsistent and limited.

METHODS

We studied complex formation of PSA secreted by cultured human prostate tissues and in the tissue by in situ proximity ligation assay (PLA). Free, total and active PSA, and the PSA-ACT complex were determined in tissue culture media by immunoassays, immunoblotting, and chromatographic methods.

RESULTS

The majority of PSA in tissue culture medium was free and enzymatically active. However, a significant proportion (1.6 ± 0.5%) of immunoreactive PSA was found to be complexed with ACT. Complex formation was confirmed by in situ PLA, which showed more intense staining of PSA-ACT in cancers with Gleason grade 3 than in adjacent benign tissues from the same patients.

CONCLUSIONS

These results show that PSA forms complexes already within the prostate and that PSA-ACT levels are increased in moderately differentiated prostate cancer tissue. This may explain, at least partially, why the ratio of serum PSA-ACT to total PSA is increased in prostate cancer.

Enzyme and hormonal markers in the differential diagnosis of human azoospermia

The serum concentrations of FSH, LH, prolactin, testosterone, and estradiol and the enzymatic activities of hyaluronidase, glucosidases (alpha-glucosidase, beta-glucosidase, alpha-mannosidase, N-acetyl-beta-D-glucosaminidase, beta-glucuronidase, and beta-galactosidase), lactate dehydrogenase and its isoenzymes (LDH1, LDH2, LDH3, LDH-X, LDH4), and total proteins were measured in the semen of 69 subjects (8 normozoospermic controls, 7 secretory, and 54 excretory azoospermic subjects). FSH levels rose with the deterioration in spermatogenesis and served to differentiate the secretory from the excretory azoospermias. The only source of hyaluronidase and LDH-X in the ejaculate is the spermatozoa. alpha-Glucosidase activity essentially originates in the epididymis. The seminal determination of alpha-glucosidase and, to a lesser extent, alpha-mannosidase and N-acetyl-beta-D-glucosaminidase helps rapidly, sensitivity, reliably, and noninvasively to differentiate secretory azoospermias (with higher enzymatic activity) from the excretory type (less enzymatic activity) and may be of use in identifying with a certain degree of reliability the site of obstruction in the male genital tract.

Characterization of acid and neutral alpha-mannosidases in bull semen and reproductive organs

Acid and neutral alpha-mannosidase activities were studied in the bull reproductive tissues, isolated spermatozoa, epididymal and seminal vesicle secretion and seminal plasma. The acid enzyme in the seminal plasma mainly derived from the epididymal secretion, while the neutral one was enriched in the sperm cells. The latter activity in the seminal plasma appears to be due to an enzyme released from the cytoplasmic droplets in the epididymis. The acid enzyme had a molecular weight of 220,000-320,000, pI 7.3-6.0 and an optimum at pH 4.0. It was sensitive to swainsonine but was stimulated by Zn2+. The neutral enzyme had a molecular weight of 360,000-460,000, pI 5.4-4.7 and showed double optima at pH 5.5 and 6.0-7.0. It was resistant to swainsonine but was markedly activated by Co2+ or Fe2+. The neutral enzyme was also more sensitive to thermal inactivation than the acid one.

Neutral alpha-1,4-glucosidase in human seminal plasma: molecular forms in varicocele and after vasectomy

Neutral alpha-1,4-glucosidase catalyzes the breakdown of oligosaccharides in several tissues including the reproductive organs, and we have demonstrated the presence of two molecular forms (F1 and F2) of the enzyme in human seminal plasma. The identification of these forms can be achieved by sucrose density gradient analysis and/or electrophoresis in the presence of detergents. Individuals with normal sperm analyses or affected by a varicocele, thus showing normo- or oligoasthenozoospermia, show a similar prevalence of F1 only and F1 + F2 forms, while the presence of F2 alone becomes obvious following vasectomy. In conclusion, molecular forms of the enzyme do not appear to be indicative of the presence of a varicocele, but they may reflect modifications in the secretory function of specific reproductive organs (prostate) or glands (seminal vesicles), as observed in the course of an obstructive abnormality at the epididymal or vas deferens level.

Reduced activity of Mg2+- and Ca2+-dependent adenosine triphosphatase in seminal fluid of patients with oligozoospermia

Mg2+- and Ca2+-dependent ATPase activity, fructose and divalent cation concentrations were determined in seminal plasmas from men with oligozoospermic ejaculates and from those with normal sperm count. The mean activity of the Mg2+- and Ca2+-stimulated ATPase from the former was 59 nmol . 0.1 ml-1 . This is significantly (p less than 0.005) lower than for men with a normal sperm count (corresponding figure is 87 nmol . 0.1m1-1 . min-1). As regards the concentrations of Mg2+, Ca2+ and Zn2+ in the seminal plasmas from these two groups there was no significant difference. The same was also valid for the fructose concentrations. The Mg2+- and Ca2+-stimulated ATPase activity as well as fructose and divalent cation concentrations were also determined in seminal plasmas from men before and after vasectomy. After vasectomy, only the ejaculates devoid of spermatozoa were included in the comparative studies. No significant difference was observed between the seminal plasmas from men before and after vasectomy. These findings support the view that the Mg2+- and Ca2+-stimulated ATPase system does not derive from the spermatozoa. Possible explanations for the significantly lowered Mg2+- and Ca2+-dependent ATPase activity from patients with oligozoospermia are given.

Prostatitis in the rat

A high incidence of spontaneous, non-acute, age-dependent prostatitis was observed in the lateral prostate of Copenhagen rats and Wistar rats. The lumen of infected acini was filled with polymorphonuclear leucocytes, shed epithelial cells and cell residues. Epithelial cells lining such acini showed degenerative changes. Lymphocytes and macrophages were seen in the stroma. A histochemically observed increase in acid phosphatase and beta-glucuronidase activity in affected epithelial cells may indicate an increased lysosomal activity. Some bacteriological cultures of infected lateral prostates were positive for Proteus vulgaris and diphtheroids. It is suggested that this spontaneous rat prostatitis may be a useful model for the study of the pathogenesis and treatment of human non-acute prostatitis.

Antimicrobial activity of human seminal fluid

The antibacterial, antifungal and antimycoplasmal activity of human semen was studied. Gram-positive aerobic bacterial species i.e. staphylococci, but not gram-negative aerobic bacteria, were inhibited by seminal fluid in vitro. Neither were anaerobic gram-positive or gram-negative bacteria, nor Candida or Mycoplasma inhibited. Semen of healthy males had a higher antibacterial effect on S. albus than that of patients with symptoms of chronic prostatitis. There was a positive correlation between the antibacterial power of the semen of the patients studied and their content of zinc and magnesium, while no correlation was found with fructose and lysozyme or the number of spermatozoa in any of the groups. A positive correlation was found between the antibacterial capacity and the volume of the ejaculate in the patients but not among the controls. The antibacterial substance(s) was dialysable, ether-extractable, resistant to boiling and partly to storage at room temperature. The addition of EDTA, tranexamic acid and ammonium reineckate to semen did not influence the antibacterial effect, which was, however, slightly inhibited by sodium polyanethol sulphonate. The nature of possible antibacterial substances in semen is discussed.