Kenneth D. Roberts

Selenium-vitamin E supplementation in infertile men. Effects on semen parameters and micronutrient levels and distribution.

In order to verify the hypothesis that selenium (Se) and vitamin E (Vit E) could improve male fertility, nine oligoasthenoteratozoospermic men were supplemented for a period of 6 mo with Se and Vit E. Compared to the baseline period (presupplementation) of 4 mo, statistically significant increases were observed for Se and Vit E levels, sperm motility, percent live, and percent normal spermatozoa. These improvements are likely to be “supplementation-dependent,” since all of the parameters returned to baseline values during the posttreatment period. None of the couples reported a pregnancy during the study. The HPLC analysis conducted on the serum of one of the patients showed the existence of at least six different Se-containing peaks, whose Se content was affected by supplementation. The mechanism(s) involved in these improvements of semen parameters is presently under investigation.

Cholesterol sulfate. I. Occurrence and possible biological functions as an amphipathic lipid in the membrane of the human erythrocyte

Abstract Cholesterol sulfate is a normal constituent of human erythrocytes at a concentration which is approximately 2-fold higher than plasma cholesterol sulfate. In these cells, the major fraction of the cholesterol sulfate is firmly bound to the membrane. Cholesterol sulfate as well as certain analogs can project the red blood cell against hypotonic hemolysis. This effect is produced in vitro at physiological concentrations of the sterol sulfate and both the sulfate moiety as well as the side chain of the molecule are necessary for biological activity.

Semen selenium and human fertility

Selenium (Se) was measured in the semen of 125 men from couples consulting for infertility. A mean concentration of 71.3 +/- 29.7 ng/ml of semen was found, with a range of 7 to 230 ng/ml. More than 85% of the Se is in the seminal plasma. There was a significant positive correlation between sperm count and semen Se. Sperm motility was maximal at semen Se levels ranging between 50 and 69 ng/ml; above and below this range, motility was decreased and the incidence of asthenospermia was high. This result suggests an optimal range for semen Se. A follow-up of 4.5 to 5 years after the initial assay of Se revealed that low semen Se levels (less than or equal to 35 ng/ml) were associated with male infertility. A Se level between approximately 40 and 70 ng/ml was optimal for reproductive performance (high pregnancy rate and low abortion rate). Semen Se levels greater than or equal to 80 ng/ml were associated with a high abortion rate and signs of ovarian dysfunction in the partner (both partners usually have the same diet and environmental exposure). These results attest to the role of Se in human reproduction, a well-established fact in several animal species. The semen Se level appears to be a useful indicator of Se status versus reproductive function. Further studies are warranted concerning the general aspects of metabolism and mechanism of action of Se in infertile couples before any therapeutic modification of intake of this element can be contemplated.

Male infertility associated with round-headed acrosomeless spermatozoa*

The properties of spermatozoa with round head syndrome in four unrelated patients are reported. The findings were as follows: (1) Electron microscopy demonstrated that all spermatozoa lacked an acrosome and postacrosomal sheath. (2) Acrosin activity was only 1% to 6% of that found in sperm obtained from fertile donors. (3) Phospholipase A2 activity was not significantly different from that of spermatozoa from donors of unknown fertility. (4) Electrophoresis of whole sperm extracts revealed deficiencies in major protein bands. (5) The round-headed spermatozoa failed to bind or penetrate the vitellus in the egg penetration test. (6) The rates of chemically induced nuclear chromatin decondensation of round-headed spermatozoa suggest that the acrosome content is not involved in this process.

Cholesteryl sulfate and sterol sulfatase in the human reproductive tract

Cholesteryl sulfate is a component of human seminal plasma (avg. 445 mug%) and spermatozoa (15 mug/10 (9) cells) and represents more than 85% of the sterol sulfate fraction. This conjugate is avidly bound by spermatozoa when compared to other steroids or steroid sulfates. Autoradiographic localization of CS associated with the spermatozoa revealed a greater accumulation of the radioactivity in the acrosomal region in many, but not all, of those cells examined. Semen is not a site of metabolism of the sterol sulfate but the enzyme, sterol sulfatase, is present in the human female reproductive tract. This cleavage enzyme was detected in Graafian follicles and the activity in the endometrium was ten-fold that found in the Fallopian tube. These findings lead to the proposal that cholesteryl sulfate, an amphipathic molecule ideally suited for interaction with membrane components and implicated in erythrocyte membrane stabilization, may be involved in membrane modifications of the spermatozoa during the process of fertilization.

Plasma estrone sulfate levels in postmenopausal women

Estrone sulfate levels were measured in the plasma of 63 postmenopausal women. The assay method involved prior extraction of the free estrogens, enzyme hydrolysis of the estrone sulfate with sulfatase and radioimmunoassay of the estrone liberated. The plasma levels ranged from 37 to 320 pg/ml (expressed as free estrone) with a mean value of 178 +/- 79 pg/ml. As observed in premenopause, estrone sulfate is quantitatively the most important circulating estrogen in postmenopausal women.

Red cell surface structure: Stabilization by cholesterol sulfate as evidenced by scanning electron microscopy

Scanning electron microscopic studies demonstrate that the normal biconcave shape of the human erythrocyte is maintained in hypotonic saline when physiological levels (10 minus 5M) of cholesterol sulfate are added to the solutions. Cholesterol sulfate is a naturally occurring sterol conjugate in plasma and erythrocyte membranes and we propose that it may belong to that class of amphipathic molecules responsible for the maintenance of structure of the erythrocyte by interaction with membrane components.

Proliferation and differentiation of canine prostatic epithelial cells in culture

When cultured in monolayers, non-secretory epithelial cells from canine prostates actively synthesize DNA, RNA and proteins; subsequently, mitotic figures and an increase in cell number are observed. During this culture period, cell size and acid phosphatase activity remain constant. As the culture proceeds, these cells mature into secretory cells as evidenced by a gradual shift in their density in Percoll gradients to the density of secretory cells and by an increase in the cellular content of acid phosphatase. During maturation, the size of the non-secretory cells increases and their morphology changes and becomes similar to that of the secretory cells. When a homogeneous population of secretory cells is cultured, DNA synthesis is minimal and few mitotic figures may be observed while cell number and cell density remain constant. Early in the culture period, their size increases and by 2 weeks their acid phosphatase activity is 2--3-fold higher than that of the non-secretory cells. Thus, upon culture, the non-secretory epithelial cells enter and proceed through the cell cycle with evidence of DNA synthesis and mitosis. Those cells leaving the cycle undergo maturation into secretory cells which further differentiate with the concomitant appearance of acid phosphatase activity. This model will be useful to study prostatic hyperplasia and hypertrophy and the control mechanisms involved in these phenomena.

Solubilization and partial purification of steroid sulfatase of human placenta

Steroid sulfatase of human placenta has been solubilized by treatment of the microsomal fraction with an amphoteric surface active agent, Miranol H2M and ultrasound. Criteria of solubility include non-sedimentation of the activity following centrifugation at 160,000 x g, its retention on Sepharose 6B and a single peak of activity after polyacrylamide gel electrophoresis. Enzyme activity was located in the same gel fractions for the two substrates tested; cholesterol sulfate and dehydroisoandrosterone sulfate. The addition of dithiothreitol was found necessary to maintain the stability of the enzyme indicating the presence of sulfhydryl groups in the molecule. A molecular weight of approximately 330,000 has been estimated from the elution volume of the enzyme system on a column of Sepharose 6B. It is believed that this protein represents a sulfatase enzyme complex composed of subunits with different specificities. From kinetic studies, a Km of 6.2 x 10(-5)M for the cleavage of dehydroisoandrosterone sulfate and a Km of 2 x 10(-6)M for the cleavage of cholesterol sulfate have been calculated.

Platelet-activating factor acetylhydrolase in human seminal plasma

OBJECTIVE To search for the presence of platelet-activating factor (PAF) acetylhydrolase activity in human seminal plasma. DESIGN Experimental. SETTING Reproductive laboratory in a university-affiliated hospital research center. PARTICIPANTS Human male volunteers were selected on the basis of apparent normal health. RESULTS Human seminal plasma contained significant levels of PAF-acetylhydrolase activity. Enzymatic hydrolysis of PAF displayed typical kinetics and was a calcium-independent process. Platelet-activating factor acetylhydrolase in seminal plasma was associated with a very high-density lipoprotein fraction. Enzymatic activity was independent of sperm count and motility. CONCLUSION Human seminal plasma contains significant levels of PAF acetylhydrolase. This enzyme may be an important factor in the regulation of PAF concentration and activity.