Zinc in human semen

Seminal zinc was measured in normospermic and infertile patients by a new colorimetric method. Analysis of semen from 5 patients with bilateral agenesis of the vas deferens showed high levels of zinc (mean value 1411.2 micrograms/ml). Lower levels were found in 6 patients with monolateral congenital or acquired obstruction (695.2 micrograms/ml). The seminal zinc level in 6 patients who had had a vasectomy or who had an epididymal blockage (125.7 micrograms/ml) was approximately the same as in 41 controls (134.6 +/- 42 +/- SD). Zinc levels were reduced in hypogonadal patients. These data suggest that zinc is secreted mainly by the prostate, while vesicular, epididymal and testicular secretions are devoid of zinc. Evaluation of this metal therefore permits the diagnosis of patency of the seminal pathways, but does not permit identification of prostatitis. No correlation was found between sperm count or motility and the seminal zinc level, nor between the latter and varicocele.     

Sialyl transferase in human semen

The activity of the enzyme sialyl transferase, which is responsible for the transfer of sialic acid, has been examined in the following human seminal plasma: (1) originating from semen with sperm counts above 30 X 10(6)/ml and exhibiting normal values of other andrological parameters; (2) from semen with sperm counts below 25 X 10(6)/ml and with other andrological parameters of poor quality; (3) from semen devoid of sperm. Additionally, enzyme activity was examined in fractionated (split) semen. The activity in plasma based on measurement of radioactivity incorporated into asialofetuin, following incubation in the presence of 14C sialic acid, was expressed as cpm both per volume and per mg protein. There was a tendency for decreased activity with the decrease in sperm density of semen. The difference, however, lacked statistical significance. Enzyme activity in split semen was significantly lower in the first than in the second fraction.     

Free l-carnitine in human semen

Spectrophotometrical (412 nm) readings of known amounts of 1-carnitine gave absorbancy changes with minimal interassay variations (8%) in the range of 15.6-125 microM. A 100-microliters volume of seminal plasma was needed for optimal assay repeatability; recoveries of added carnitine were linear (r = 0.998), indicating a sensitivity limit of 0.70 microgram/ml. Intraassay and interassay repeatability gave variation coefficients of 2% and 1.2%, respectively. By this method, 20 samples in duplicate were analyzed within 2 h. Carnitine levels and semen volumes were inversely correlated (r = 0.49). The ejaculated amounts of carnitine (microgram/ejaculate) were not significantly different in 16 normozoospermic subjects and in 13 oligozoospermic patients. Undetectable levels of carnitine were found in case of deferential-vesicular agenesis, and very low levels were found in cases of monorchidism, confirming the epididymides as major producing organs of the substance. Very low levels were also found in semen of men with varicocele, suggesting that seminal carnitine would be regarded as an index of androgenization.     

Selenium, rubidium and zinc in human semen and semen fractions

The levels of selenium, rubidium and zinc were determined in samples of semen, seminal plasma and spermatozoa from men with suspected infertility, together with several parameters of semen quality. The proportion of whole semen selenium present in sperm increased with increasing sperm count from 0 to 40%. For rubidium 98 +/- 4% and for zinc 95 +/- 8% of the total amount in semen was contained in seminal plasma. In seminal plasma a positive correlation was found between the levels of zinc and selenium, and between the levels of zinc and rubidium, indicating that, like zinc, selenium and rubidium in seminal plasma also derive mainly from the prostate gland. Semen quality parameters, such as sperm motility, vitality, speed and morphology, were not correlated with the contents of the three elements in either whole semen or seminal plasma. As the seminal content of selenium is dependent on the proportion of prostatic secretion in seminal plasma and on the sperm count, and both factors can vary considerably, the selenium level of whole semen does not appear to be a suitable parameter for investigation of the relationship between selenium and semen quality. Provisional measurements suggest lower sperm selenium levels at abnormally low or high sperm counts.     

Cryopreservation of human semen

A review is given of the techniques for the cryopreservation of human semen, including the preparation of cryoprotective media, the use of ampoules, straws, and pellets, and freezing and thawing techniques. The use of cryopreserved semen for therapeutic artificial insemination by donor is described. The advantages of cryopreserved semen over fresh donor semen mostly lie in the ability to exclude infections before use and the extra convenience, in spite of the lower success rate and increased cost. The recovery of sperm motility on thawing is described, as are other methods for assessing the degree of damage to the spermatozoa by the freezing procedure. The success rates reported by large semen banks are summarized.     

Nonsperm cells in human semen and their relationship with semen parameters

The prevalence and clinical significance of leukocytes (WBC) and immature germ cells in semen is currently a matter of controversy. The aim of this work was to assess the prevalence of leukocytospermia in semen samples from Venezuelan men and its possible effects on sperm parameters. The concentration of WBC and round cells (RC) was evaluated in 118 semen samples from 19 fertile subjects (group 1), 62 infertile patients (group II), and 37 men with varicocele (group III). Semen WBC concentration was assessed by peroxidase assay. Twenty-six (22%) of the total samples had more than 10 WBC/mL semen. Twenty of the infertile men had leukocytospermia (32%) compared with 16% in the fertile group and 8% in the varicocele group. Semen RC concentration was lower than 5 x 10(6)/mL in all groups but, in groups II and III was significantly higher compared with group I. Infertile men had the highest WBC concentration. WBC concentration was negatively correlated with progressive motility, percentage of morphologically normal sperm, and hypoosmotic swelling test in infertile men but not in the varicocele group. In this group a negative correlation was obtained between immature germ cells and normal sperm morphology. The data show that leukcytospermia occurs frequently in infertile patients and is associated with poor semen quality parameters. In contrast, in men with varicocele, the increased number of immature germ cells might play a pivotal role in the pathogenesis of abnormal spermatozoa.     

pH of human semen

The World Health Organization (WHO) laboratory manual (1992) states the normal values for pH in liquefied semen to be between 7.2 and 8.0. This implies an adjustment compared with the previous version ( WHO, 1987 ) in which the upper limit was 7.8, whereas in the WHO clinical manual (1993 ) the normal range of values is still stated to be in the range of 7.2–7.8. In this study pH was measured in ejaculates from 207 men in couples undergoing infertility examination. The pH was measured within 30 and 60 min after ejaculation with both pH paper and pH meter. The mean pH values were consistently well above 8.0 regardless of analysis method and time after ejaculation. Since semen analysis is part of clinical assessment of male infertility and includes pH measurement, our findings suggest that the range of normal values needs to be revised further.     

Circannual variation in human semen parameters

The aim of the present study was to determine whether there were significant monthly variations in the semen parameters (i.e. volume, sperm count, total sperm count, motile and normal sperm count) of men living in a Mediterranean climate area. A total of 10 877 semen analysis results were included. Semen samples were obtained as a part of an initial screening of male partners from couples with infertility problems who were attending our laboratory from 1970 to 2000. Log transformation and cubic root transformation were used to test the sample distribution. Statistical significance was adjusted by year of examination, patient's age and sexual abstinence period by performing covariance analyses. Differences between months were assessed with the Bonferroni post-hoc test. There was an increase in March and a decrease in September in the adjusted mean sperm count (p < 0.0005), total sperm count (p < 0.0005), motile sperm count (p=0.01) and normal sperm count (p=0.002). There were no variations in semen volume in the study period. Monthly changes in semen quality are confirmed in this population.     

Beta-endorphin and calcitonin in human semen

The levels of beta-endorphin (beta-E) and calcitonin were estimated in 36 samples of seminal plasma from semen of normospermic, oligozoospermic, and azoospermic origins and in pools of isolated sperm. The mean levels in plasma calculated for all samples examined were 192 +/- 224 pg/ml for beta-E and 754 +/- 397 pg/ml for calcitonin. The amounts in sperm were as follows: for beta-E in pools with sperm counts of 0.1-10 x 10(6)/ml, 157.2 +/- 99.7 pg/10(8) and 27.9 +/- 23.6 pg/ml protein; in pools of greater than 10-30 x 10(6)/ml, 71.2 +/- 41.5 pg/10(8) and 6.5 +/- 1.2 pg/mg protein; in pools of greater than 30-200 x 10(6)/ml, 24.9 +/- 9.7 pg/10(8) and 61 +/- 1.9 pg/mg protein. For calcitonin the amounts were: 501.2 +/- 170.8 pg/10(8) and 27.4 +/- 21.5 pg/mg protein, correspondingly. It was suggested that beta-E and calcitonin present in seminal plasma are synthesized mostly in a compartment of the male reproductive system. The high cellular beta-E and calcitonin levels would be involved in the process of motility through their effect on calcium transport.     

Acid phosphatase activity in human semen.

Acid phosphatase activity was examined in normal and abnormal human semen of individuals not suffering from testosterone deficiency. No differences in enzymatic activity between the examined groups were observed. The presence of tartaric acid caused an inhibition of about 95% of enzymatic activity.     

Tissue polypeptide antigen immunoreactivity in human semen

A substance with TPA immunoreactivity is present in human seminal plasma. This seminal plasma TPA shows immunological similarity with TPA isolated from a pool of carcinoma tumors. TPA is taken up by live spermatozoa and it cannot be easily washed out. Split-ejaculate studies suggest that TPA originates mainly from the prostate. TPA is not correlated with the spermatozoa count, total number of spermatozoa, percentage of normal spermatozoa, or forward motility. The mean seminal plasma concentration of TPA in morphologically normal ejaculates is 14,531 U/liter. No difference was found in the TPA levels between the normal group and various groups of patients under investigation for involuntary infertility.     

Determination of phthalate esters in human semen

Phthalate esters are a large group of chemical compounds used in the production of plastics, household articles, packages, cosmetics and plant pesticides. World production of phthalates is estimated to be several million tons a year. Recent observations indicate some mutagenic, cancerogenic and orchidotoxic effect of these compounds. Therefore, to assess the extent of risk it is imperative to have an adequate analytical method. The following is simple and relatively inexpensive. The study group consisted of 58 men.     

Human chorionic gonadotropin beta-subunit in human semen

The level of human seminal chorionic gonadotropin beta-subunit (hCG beta) was determined by radioimmunoassay (RIA). The mean hCG beta level in 34 normal men was 3.7 +/- 1.6 ng/ml, which was much higher than that in serum. The mean hCG beta level for 20 patients with mild oligozoospermia (20-39 x 10(6) sperm/ml) was 2.5 +/- 0.8 ng/ml, that for 34 patients with severe oligozoospermia (1-19 x 10(6) sperm/ml) was 1.7 +/- 0.5 ng/ml, and that for 21 azoospermia was 1.5 +/- 0.6 ng/ml. Thus, the decrease of sperm count was correlated with the decrease of hCG beta. In 17 cases to which testicular biopsy was applied together with sperm counting, the seminal hCG beta level was found to positively correlate with the germinal cell index (the ratio germinal cell count/Sertoli cell count) and with the testicular volume. The level of seminal hCG beta was also found to correlate negatively with the levels of seminal LH and FSH and positively with the level of seminal testosterone. These findings suggest that the production of seminal hCG beta is a process of spermatogenesis and closely related to spermatogenesis. The level of hCG beta in serum was too low to detect, and no relation to that in seminal plasma could be investigated. However, in 6 cases with testicular tumor, the hCG beta level in serum was high, whereas that in seminal plasma was rather low probably because of unilateral secretion. Enhanced production of hCG beta by tumor tissues and the destruction of the blood-testis barrier by proliferation of tumor cells seemed to be one of the causes of this high hCG beta level in serum. The hCG beta levels in 13 vasectomized seminal plasma and the prostatic fluid samples collected from 3 normal men were 1.5 ng/ml, which was similar to those in azoospermic patients. These findings suggest that the seminal hCG beta level consists of the hCG beta secreted by the testis and about 1.5 ng/ml of hCG beta from the prostate. Based on these results, seminal hCG beta is thought to be secreted by the prostate and the process of spermatogenesis and the value of seminal hCG beta may serve as an effective index for the testicular function.