Follicular fluid and human granulosa cell cultures: influence on sperm kinetic parameters, hyperactivation, and acrosome reaction

OBJECTIVE

To evaluate the influence of human granulosa cell (GC) cultures and follicular fluid (FF) on sperm kinetic parameters, hyperactivation, and the acrosome reaction compared with the influence of human tubal fluid (HTF) and Ham's F-10 medium.

DESIGN

Sperm kinetic parameters, hyperactivation, and the acrosome reaction were evaluated after 6 hours of incubation in HTF, Ham's F-10 medium, FF, and GC cultures.

SETTING

Infertility and In Vitro Fertilization Centre, Reproductive Endocrinology Unit, Institute of Obstetrics and Gynaecology.

PATIENT(S)

Sixteen normal semen samples.

INTERVENTION(S)

Sperm kinetic parameters and hyperactivation were analyzed using an automated videomicrography system, the acrosome reaction was performed using a triple-stain technique, and progesterone and 17OH-progesterone levels were measured with the use of commercially available kits.

MAIN OUTCOME MEASURE(S)

Sperm kinetic parameters, hyperactivation, acrosome reaction.

RESULT(S)

The percentage of motile sperm, the mean curvilinear velocity, and the mean of the maximum amplitude of lateral head movement were increased significantly after 6 hours of incubation in FF or GC cultures compared with incubation in HTF or Ham's F-10 medium, whereas the mean linearity was decreased significantly. Follicular fluid and GC cultures significantly increased hyperactivation and the acrosome reaction compared with the values obtained using HTF and Ham's F-10 medium. Progesterone and 17OH-progesterone levels were increased significantly after incubation in FF and GC cultures compared with HTF and Ham's F-10 medium.

CONCLUSION(S)

Follicular fluid and GC cultures increase sperm motility parameters, hyperactivation, and the acrosome reaction. This effect may be related to GC detoxification of the microenvironement or GC secretion of peptides, glycoproteins, growth factors (insulin-like growth factors 1 and 2), or steroids (progesterone and 17OH-progesterone).

New and traditional approaches for the assessment of testicular toxicity

In this study, the suitability of several methods for the assessment of testicular damage, including histopathology, flow cytometry (FCM), testicular sperm head counts, and secretion of androgen binding protein (ABP), has been evaluated. Testicular toxicity after acute exposure of adult rats to different doses of the known toxicant 1,3-dinitrobenzene (DNB) was analyzed. The effects showed dose dependence, in spite of the large variability within each dose group. Histopathology and FCM showed germ cell depletion, particularly of round spermatids; testicular sperm head counts were reduced and ABP production was increased. All evaluated methods showed similar sensitivities. The increased testicular ABP levels support the theory that the Sertoli cell is the likely target of DNB induced testicular toxicity, producing subsequent germ cell depletion. The presented results show the suitability of FCM for the analysis of testicular damage and also support the usefulness of including a metabolic marker for Sertoli cell function.

Effects of some beta-adrenergic blockers on male fertility parameters in rats

The effects of atenolol (9 and 18 mg/kg.b.wt.), metoprolol (3.5 and 7 mg/kg.b.wt.) and propranolol (7.5 and 15 mg/kg.b.wt.) on male rate fertility were investigated following repeated oral administrations for 60 consecutive days. Repeated administrations of atenolol (9 and 18 mg/kg.b.wt.) induced non significant effects on weights of testes, epididymis and seminal vesicle at the first day, 30 and 60 days after the last repeated oral administration for 60 days. Administration of atenolol (9 and 18 mg/kg.b.wt.), metoprolol (3.5 and 7 mg/kg.b.wt.) and propranolol (15 mg/kg.b.wt.) to male rats induced significant decrease in percent of progressive motility of sperm at first day after the last oral administration for 60 days. Atenolol (18 mg/kg.b.wt.), metoprolol (7 mg/kg.b.wt.) and propranolol (7.5 and 15 mg/kg.b.wt.) induced significant increase in sperm head and tail abnormalities at first day after the last repeated dose. All rats treated with atenolol (9 mg/kg.b.wt.), metoprolol (7.5 and 15 mg/kg.b.wt.) and propranolol (7.5 and 15 mg/kg.b.wt.) induced significant decrease in the level of testosterone hormone at first and 30 days after the last dose. Repeated administrations of atenolol, metoprolol and propranolol in therapeutic and double therapeutic doses for 60 days induced nearly similar histopathological alterations in testis, epididymis and seminal vesicles. The induced hazard effects by the tested drugs on the male rat fertility were reversible as they returned to normal values 60 days after discontinuation of therapy.

Evaluation of the mutagenicity of acetochlor to male rat germ cells

Male rat dominant lethal (DL) assays conducted on the herbicide acetochlor are described. Single dose studies conducted at the maximum tolerated dose (MTD, < or = 1000 mg/kg) produced no effects on any of the DL assay parameters at any of the ten weekly sampling periods. It is concluded that acetochlor is non-mutagenic to rat germ cells. Due to initial limited knowledge of the MTD of acetochlor it was also evaluated in the DL assay at a dose level of 2000 mg/kg. At this high dose level severe bodyweight loss and some deaths occurred among the treated animals. In addition, reduced implantations and reduced pregnancy rates were observed at the third sampling period (18-25 days post dosing) in the absence of an increase in early post-implantation deaths. These results indicated that the use of supra-MTD doses of acetochlor had reduced the fertility of the treated males leading to the production of a pseudo-DL assay response, as alerted to and defined by Ehling. Although several such pseudo-DL assay responses have been described, none have been explained mechanistically. It was therefore decided to pursue the effects seen in the DL assay when using supra-MTD doses of acetochlor. Ova analysis of female rats mated with male rats exposed to 2000 mg/kg acetochlor revealed unfertilized ova at the critical third sampling time. Normal fertilization of ova was observed at the first and fifth sampling period and, for a dose of 200 mg/kg acetochlor, at the third sampling period. The magnitude and temporal nature of these effects confirmed the induction of a pseudo-DL assay response, and studies were then undertaken to probe its genesis. Rats treated with 2000 mg/kg acetochlor had normal testicular and epididymal pathology and normal sperm numbers and sperm motility at the critical third sampling period. Despite a small reduction in testicular and epididymal glutathione levels 12 h after exposure to 2000 mg/kg acetochlor, testicular LDH and LDH-X enzyme levels were unaffected. Further, no reduction in the level of free sulphydryl groups (-SH) were observed in epididymal caput sperm heads isolated 0.5, 7 or 14 days after treatment of male rats with 2000 mg/kg acetochlor. The only sperm parameter affected by treatment with 2000 mg/kg acetochlor was an increase in epididymal cauda sperm with head abnormalities. The non-specific nature of this effect was considered inadequate to explain fully the high dose fertility effects seen in the DL assays, which therefore remain unexplained. The present data establish that acetochlor is non-mutagenic to rat germ cells. They also confirm the importance of segregating mutagenic and fertility effects in the DL assay, and emphasize the need for appropriate dose-setting studies prior to the conduct of rodent genetic toxicity assays.

The effect of 12-myristate 13-acetate phorbol ester on human sperm hyperactivation

OBJECTIVE

To determine whether 12-myristate 13-acetate phorbol ester (PMA) can increase hyperactivated motility of human sperm.

DESIGN

A controlled pharmacological study using computer-assisted semen analysis.

SETTING

Andrology laboratory in a medical research institution.

PATIENT(S)

Normal semen was obtained from 48 men.

INTERVENTION(S)

Washed sperm were exposed to different concentrations of PMA alone or with P and pentoxifylline (PTX) for up to 2 hours and sperm motility measured by a computer-assisted semen analyzer.

MAIN OUTCOME MEASURE(S)

The percentage of sperm with hyperactivated motility was determined from the motility parameters: curvilinear velocity, linearity, and maximum amplitude of lateral head displacement.

RESULT(S)

Phorbol ester PMA increased hyperactivated motility in a dose- and time-dependent manner. At 1 hour, the average increases in hyperactivated motility were as follows: 2 microM, 4.8% +/- 1.5%; 6 microM, 9.6% +/- 1.5%; and 20 microM, 11.3% +/- 2.2%. The PMA effect was not altered when P or PTX were added although each separately had a positive effect on hyperactivation.

CONCLUSION(S)

Phorbol ester PMA stimulates human sperm hyperactivated motility, indicating the involvement of protein kinase C in the signal transduction pathway.

A study on the reproductive toxicity of erythrosine in male mice

Worldwide usage of different colouring agents in the food industry prompted us to study their toxicity. The potential adverse effects of erythrosine (ER, FD & C Red No. 3) on the spermatogenesis process were investigated in adult mice. Testicular lactic dehydrogenase isoenzyme activity (LDH-X), a pachytene spermatocyte marker of testicular toxicity, was significantly decreased to 71.8% and 68.6% of the control value after daily p.o. administration of ER (21 days) in doses of 68 and 136 mg kg-1 respectively. At the same time, the normal average epididymal sperm count as well as the percentage of motile sperms were significantly inhibited by about 50% and 57% respectively. Moreover, ER was shown to disrupt the normal morphology of the sperm head. Thus, after 5 daily p.o administrations of ER in doses of 680 and 1360 mg kg-1 (equivalent to 10 and 20% of its LD50) it increased the incidence of sperms with abnormal head by about 57% and 65% respectively. The induced increase in sperm abnormalities could enhance the spermatogenic dysfunction and germ cell mutagenicity. These findings indicate that ER in the used doses has a potential toxic effect on spermatogenesis in mice and in turn, it may affect its testicular function and reproductive performance.

Sperm head abnormalities and dominant lethal effects of formaldehyde in albino rats

The effects of formaldehyde exposure have been investigated in rats by two short-term in vivo mutagenicity tests (sperm head abnormality and dominant lethal mutation assays). Five daily interperitonial injections of formaldehyde resulted in a statistically significant increase in induction of sperm head abnormalities at 0.125 to 0.500 mg/kg. The frequency of dominant lethal mutations in female rats sired by males exposed to formaldehyde was significantly higher than the control group. There was also a reduction of fertile matings in females mated 1-7 days after treatment of males with formaldehyde. The genetic and environmental health implications of the results are discussed.

Implication of sperm head agglutination induced by a V3 peptide (fragment 307-330, HIV-1 envelope protein gp120) solution

Human semen is the main vehicle for the transmission of human immunodeficiency virus (HIV); therefore, the interaction of HIV with the sperm is worthy of study. The motile sperm head fixation method was used as an in vitro model system to demonstrate the interaction of sperm with the peptide of HIV envelope protein. A micropipette loaded with semen was put into phosphate-buffered saline (PBS) containing V3 peptide (HIV-1IIIB envelope protein, fragment 307-330) or C2 peptide (HIV-1IIIB envelope protein, fragment 254-274). The V3 peptide caused a significant number of head-to-head binding sperm while the C2 peptide did not. This V3 peptide carries a high positive charge, which may overcome the electrostatic resistance on the cell to bring the sperm together. An HIV-CD4+ cell attachment inhibitor, dextran sulfate (DS, molecular weight about 5000), enhanced the sperm head agglutination induced by the V3 peptide. DS is presumed able to bind with specific sites near the V3 domain of gp120 to induce conformational change so as to prevent the binding of anti-V3 monoclonal antibodies or CD4+ cells to the V3 domain. This study suggests that DS interacts directly with the V3 peptide to enhance the sperm head agglutination.

Evaluation of the subacute pulmonary and testicular inhalation toxicity of diborane in rats

This study aimed to clarify the subacute pulmonary and testicular inhalation toxicity of diborane (B2H6, CAS: 19287-45-7) in rats. Male Wistar rats were exposed for 8 weeks to 0.11 or 0.96 ppm of diborane for 6 hr/day, 5 days/week. The control group was exposed to filtered air. Bronchoalveolar lavage fluid (BALF), hematological, biochemical, and histopathological examinations were conducted. Sperm counts and spermatic morphological changes were examined in epididymides, and histopathological examination was carries out in testes. BALF examinations revealed that the percentage of neutrophils increased in a dose-dependent manner and that of macrophages decreased in rats exposed to 0.96 ppm. Quantities of total and individual phospholipids in BALF increased in rats exposed to 0.96 ppm. The proportion of phosphatidylglycerol plus sphingomyelin decreased, and phosphatidylethanolamine and phosphatidylinositol increased in rats exposed to 0.96 ppm. LDH increased in rats exposed to 0.96 ppm, and ALP showed a dose-dependent increase. In serum, alpha 1-antitrypsin and superoxide dismutase activities increased in rats exposed to 0.11 or 0.96 ppm. These changes showed dose-dependent effects on the lung in rats exposed to diborane, possibly indicating that the hyperenergia of type II cells with proliferation and/or hypertrophy without histopathological changes occurred even in rats exposed to 0.11 ppm. Testicular examinations revealed no particular findings. The TLV-TWA of diborane (0.1 ppm) seems to be high and possibly unsafe, considering that the no-observed-effect level over 8 weeks for rat lung was under 0.11 ppm.

Ameliorating effect of vitamin C on murine sperm toxicity induced by three pesticides (endosulfan, phosphamidon and mancozeb)

The ameliorating effect of vitamin C (injected intraperitoneally) was evaluated against changes in sperm count and sperm head morphology in mice fed either 3, 6 or 1000 mg/kg body wt/day endosulfan, phosphamidon or mancozeb, respectively. The animals received aqueous preparations of the pesticides and/or vitamin C once daily for 35 consecutive days. All three pesticides, irrespective of their chemical nature, significantly decreased the sperm count, as well as increased the frequency of sperm with aberrant head morphology. Out of the three doses of vitamin C used the middle and higher ones (20 and 40 mg/kg body wt/day, respectively) afforded comparatively more significant amelioration. The lower dose (10 mg/kg body wt/day) of this vitamin (quantitatively equivalent to the human therapeutic dose according to body weight) was least efficacious in both the tests. However, amelioration was never up to the control level in any case. Vitamin C doses, when administered alone, did not produce any adverse effect on sperm count and sperm head morphology.

Effect of glyceryl trinitrate on sperm motility and lipid peroxidation in normozoospermic men

The objective of this study was to assess the in-vitro effects of the nitric oxide substrate glyceryl trinitrate (GTN) on sperm motility and membrane lipid peroxidation. Nitric oxide (NO) can impair sperm motility, possibly by an alteration of cyclic nucleotide levels. NO may also be protective against lipid peroxidation. Semen samples from nine normospermic men were prepared by a swim-up technique. Each specimen was divided into four aliquots, one of which was the control sample. The other three had 10(-6), 10(-8) or 10(-10) M GTN added. Sperm motility was then analysed over 180 min using a Hamilton Thorn motility analyser. Lipid peroxidation was assessed by measuring media malondialdehyde (MDA) levels at 180 min. Compared with control, the following measurements were reduced (p < 0.05) over the first 60 min in the 10(-6) M GTN aliquots only: mean path velocity (reduced by 14-15%), curvilinear velocity (reduced by 12-21%), straight-line velocity (reduced by 18-19%) and percentage of hyperactivated spermatozoa (reduced by 38-43%). MDA levels and head movement parameters were comparable amongst all aliquots (p > 0.05). The depressant effects of GTN on sperm motility appeared to be transient and reversible. The effects observed may be due to NO generated by GTN, or to GTN itself. This suggests that NO may have a role in vivo as a physiological inhibitor of sperm motility. The addition of GTN did not appear either to cause sperm membrane damage or to protect the spermatozoa from lipid peroxidation.

Dibromoacetic acid affects reproductive competence and sperm quality in the male rat

Recently, we demonstrated with short-duration tests that dibromoacetic acid (DBAA), a commonly occurring by-product of water disinfection, alters sperm morphology and motility in the male rat. These results suggested that the effects of DBAA on sperm quality were likely to compromise reproductive competence of the male rat early in subchronic exposure. The present studies were undertaken to investigate the dose response and time course of alterations in fertility and sperm quality. Proven breeder male rats were gavaged daily with 0, 2, 10, 50, or 250 mg DBAA/kg for up to 79 days; interim and terminal measurements of sperm quality and reproductive outcome were made. Because of the known neurotoxicity of the analogue, dichloroacetic acid, both natural breeding and artificial inseminations were evaluated in untreated females to distinguish between possible behavioral and spermatogenic effects. DBAA compromised male fertility during the second treatment week in naturally bred rats dosed with 250 mg/kg. The early antifertility effect appeared to be the result of behavioral changes since females artificially inseminated with sperm collected on Day 9 successfully produced offspring. However, sperm morphology and motility also were rapidly affected by DBAA treatment so that no offspring via natural insemination and only one litter via artificial insemination were produced subsequent to Day 15. Through 31 days, substantial effects on sperm motility, sperm morphology, and epididymal sperm numbers were observed, but there was no demonstrable effect on serum testosterone or sperm production. Because severe toxicity developed in the group given 250 mg/kg, exposure of these animals was prematurely terminated after 42 doses and their recovery was monitored through a 6-month posttreatment period; decreased testis weights and only limited recovery of reproductive performance were observed. Exposure to 50 mg/kg resulted in moderate changes in sperm morphology and motility and moderate decreases in epididymal sperm counts in rats dosed for 31 or 79 days. However, these males remained fertile, litter size was unaffected, and no paternally mediated developmental defects were noted in their offspring. No effects on sperm quality were detected at dosages of 2 or 10 mg/kg. However, compared to controls, naturally bred DBAA-treated rats tended to have fewer inseminations, fewer copulatory plugs, and fewer multiple litters, suggesting that DBAA may have altered mating behavior at dosages as low as 10 mg/kg.

Effects of nitrofurazone on spermatogenesis and reproductive toxicity in male rats--part of a collaborative work to determine optimal administration period and endpoints

To determine an appropriate administration period and sensitive end-points for the evaluation of effects on male fertility, male Sprague-Dawley rats were orally given nitrofurazone, a model compound, at doses of 12.5, 25, or 50 mg/kg/day for 4 weeks, or at doses of 12.5 or 25 mg/kg/day for 9 weeks before mating with untreated females. Copulation and fertility indices were decreased, and pregnancy did not result at doses of 25 mg/kg/day and over with both dosing periods. An increase in preimplantation loss, and decreases in implants and live fetuses were observed with 12.5 mg/kg/day after 9-weeks dosing. However, no reproductive endpoints were affected by the same dose level for 4-weeks. Sperm head count was reduced at doses of 25 mg/kg/day and over with both dosing periods. Histopathology revealed tubular degeneration and interstitial cell hyperplasia at doses of 25 mg/kg/day and over after both periods of dosing. Moreover, failure of spermiation in tubular epithelia was also detected in the 12.5 mg/kg groups. These results suggest that 4-weeks premating exposure is sufficient for evaluation of the effects of nitrofurazone on mate fertility, and the most sensitive endpoint in this 4-week premating-dose study is a histopathological change.

Male fertility in rats treated with etretinate for 4 weeks

The toxicity of Etretinate, a retinoid compound, on the male reproductive system was studied in male rats. The drug was administered for four weeks at the dose levels of 0 (control: Vehicle, Peanut oil), 5 and 25 mg/kg/day. The animals were then allowed to mate, and their male reproductive functions and organs were examined in detail. No significant changes due to toxicity were observed in male reproductive functions and organs in the 5 mg/kg/day group after the 4-week treatment. In contrast, males in the 25 mg/kg/day group showed drug-related changes in their reproductive performance (decrease of mating ability and fertility rate), testosterone blood level, sperm head counts, sperm viability and number in the caudal epididymis, organ weight and in the histopathology of their reproductive organs (atrophy of seminiferous tubules, necrosis of spermatocytes and spermatids, vacuolation of nuclei of spermatocytes and spermatids). Even though Etretinate belong to the retinoid group of compounds, the changes seen in the 25 mg/kg/day group were almost the same as those observed in Vitamin A-deficient animals. In conclusion, there is a correlation between changes due to toxicity observed for parameters of male fertility and for histopathological evaluation of the testis of rats that receiving high dose, treatment with Etretinate for 4 weeks.

The use of an in vitro sperm activation assay to detect chemically induced damage of human sperm nuclei

A human sperm activation assay (HSAA) has recently been developed to assess sperm quality and functionality. The HSAA involves incubating lysolecithin-permeabilized sperm in Xenopus laevis ova cytoplasmic extract. Factors in the extract activate sperm nuclei; the activation involves sperm chromatin decondensation, DNA synthesis, and chromatin recondensation. We report that human sperm chemically damaged in vitro by treatment with a reversible crosslinker, ethylene glycolbis(sulfosuccinimidylsuccinate; SEGS), display abnormal chromatin decondensation when analyzed in the HSAA. Less than 20% of SEGS-treated sperm fully decondensed, vs. 97% of control sperm. Chemical reversal of the crosslinks by treatment with 5 microM hydroxylamine restored full decondensation in 76% of treated sperm. These results demonstrate that chemically damaged sperm respond abnormally in the HSAA, and that chemical damage to sperm nuclei can be detected using the HSAA. Thus, there is potential for the HSAA to be used to detect chemical alterations of sperm nuclei from men exposed to environmental toxicants.

Mutagenicity testing of a rodenticide, zinctox (zinc phosphide) in a mouse in vivo system

The genotoxic potential of zinctox (zinc phosphide) was evaluated in mice in vivo employing different bioassays: bone marrow chromosome aberration, micronucleus and sperm shape abnormality. A significant increase of chromosome aberrations was induced by three doses. Interestingly, the highest percentage was induced by the middle dose. In a route-responsive study the highest percentage of chromosome aberration was induced by the oral route. A dose-dependent increase in the incidence of micronuclei was noticed in the bone marrow cells. In the sperm shape abnormality test a high percentage of abnormal sperm was induced by all three dose levels. The results revealed the genotoxic potential of zinctox in the tested mouse in vivo system.

Effects of chronic low-dose cyclophosphamide exposure on the nuclei of rat spermatozoa

Previous studies from our laboratory have shown that chronic exposure of the father to low doses of cyclophosphamide results in a significant increase in early embryonic death with little effect on the male reproductive system in rats. Such effects on progeny outcome are hypothesized to be mediated by an action of the drug on the nucleus of spermatozoa. The purpose of the present studies was to investigate the effects of cyclophosphamide treatment for 1 or 6 wk on the pattern of decondensation of sperm nuclei and on the sulfhydryl content of sperm nuclear proteins. Adult male rats were treated with cyclophosphamide (6.1 mg/kg/day) daily for 1 or 6 wk. Cauda epididymal spermatozoa were collected, demembranated, and then incubated with dithiothreitol (DTT) and proteinase K. The in vitro decondensation pattern of the nuclei of spermatozoa was divided into two phases: nuclear swelling and nuclear elongation. Spermatozoa from animals treated for 1 wk with cyclophosphamide showed the same decondensation pattern as those treated with vehicle (saline) alone. However, spermatozoa from animals treated for 6 wk with cyclophosphamide showed normal initial nuclear swelling but had a markedly affected nuclear elongation pattern. The changes with time in the decondensation pattern of these spermatozoa were quantitated by morphometric analysis of the head region of the spermatozoa. The nuclear area, curvature, and length of spermatozoa obtained from chronically drug-treated males were all significantly smaller than for those obtained from controls, while cell diameter was not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of peritoneal fluid from patients with minimal stage or treated endometriosis on sperm motility parameters using computer-assisted semen analysis

The aim of this study was to determine the influence of peritoneal fluid from patients with minimal stage or treated endometriosis on sperm motility parameters. Peritoneal fluid aspirated at diagnostic laparoscopy for unexplained infertility from women during the luteal phase of the menstrual cycle (days 20-23) was incubated for 5 h with fresh semen samples obtained from men of recently proven fertility. Spermatozoa were prepared by a swim-up technique from unprocessed semen. Using computer-assisted semen analysis (Hamilton-Thorn Research, MA, USA), sperm motility and motion parameters were observed at 0, 120, 180 and 300 min. Compared with spermatozoa incubated in Earle's balanced salt solution/human serum albumin, the percentage motility, percentage progressive motility and progressive velocity of spermatozoa incubated in peritoneal fluid from patients without visible endometriosis were significantly higher (P < 0.05). Maximal effect was observed at 3 h and maintained until 5 h. We conclude that in an in-vitro study, in contrast to peritoneal fluid from patients with minimal stage endometriosis, peritoneal fluid from patients with unexplained infertility and no visible endometriosis can improve sperm motility when compared with culture medium.

No evidence of effect on male mice germ cells after acute treatment with thiram

Thiram is a dithiocarbamate compound widely used for industrial processes and agriculture. Animal studies reveal that this compound may affect the male reproductive system. Aim of this study was to test, using sensitive testicular parameters, whether thiram directly affects germinal cells. For this purpose, B6C3F1 mice were intraperitoneally injected with thiram in oil (single dose: 75 mg/kg; repeated five daily doses: 25 mg/kg). Although both treatments were toxic, none of the parameters examined, i.e., testis weight, spermatid head number, specific enzyme levels at different times after treatment (14, 28, 35, 56 days) showed significant variations from the controls. On the contrary, in the positive controls (treated with chlorambucil), a marked reduction of sperm head number as well as a decrease of lactate dehydrogenasex and sorbitol dehydrogenase activity levels were evidenced at day 28, with a tendency to recover at day 35. Under these conditions thiram did not cause cytotoxicity on differentiating spermatogonia and on late spermatocyte stages of mice gonads.

Automated analysis of toxicant-induced changes in rat sperm head morphometry

An automated sperm morphometry analysis (ASMA) instrument was developed to obtain measurements of toxicant-induced changes in rat sperm head morphometry. 1,3-dinitrobenzene (1,3-DNB), a testicular toxicant known to affect sperm parameters, was used. Twelve-week-old Sprague-Dawley rats were allocated to a control (C) and to two 1,3-DNB treatment groups (T1 = 15 mg/kg; T2 = 25 mg/kg). 1,3-DNB was administered as a single dose by gavage, and animals were sacrificed 22 days after exposure. Sperm were collected, and morphology smears were made by a standard method. One hundred sperm heads were digitized on each slide, and 8 metric measurements were automatically reported. All measurements tended to decrease in a dose-dependent manner with increasing doses of 1,3-DNB. All values for total width (Wa) and interior width (W(e)) were significantly different from one another. Wa/L was significantly larger in the control than in T1 or T2, and symmetry (S = Wb/Wa) was significantly smaller in the control than in T1 or T2. Multivariate cluster analysis revealed three subpopulations that were also visually distinct. Subpopulation no. 1 was normal, based on published descriptions of normal rat sperm; subpopulation no. 2 was abnormal with a flattened curvature and a normal length; subpopulation no. 3 was abnormal with a foreshortened length and a flattened curvature. T1 and T2 contained significantly more sperm from subpopulation no. 2 and no. 3 than C (T1 = 22% and T2 = 34% vs. C = 8% by cluster analysis). C had 93% normal sperm, while the treatments had 78% and 66%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent effects of pentoxifylline on human sperm motility, after drug removal, in normozoospermic and asthenozoospermic individuals

The aim of the study was to compare the in vitro effect of pentoxifylline on human sperm motility when added prior to sperm selection and the persistence of the response after drug removal in normo- and asthenozoospermic individuals. The sperm samples were obtained from 22 men who were repeatedly asthenozoospermic or normozoospermic. Sperm movement was measured using computer-assisted semen analysis over 180 min. Percentage motility and progressive motility were increased in both normo- and asthenozoospermic samples (P < 0.05). Curvilinear velocity, amplitude of lateral head displacement and beat-cross frequency were increased in both groups (P < 0.05). Straight-line velocity was increased significantly in the normozoospermic group only. In both normo- and asthenozoospermic individuals pentoxifylline appeared to enhance sperm motility for at least 180 min after drug removal. This should prevent any potentially toxic effects of the drug on oocytes if it is used to enhance sperm motility during in vitro fertilization.

Modulation of ochratoxin-produced genotoxicity in mice by vitamin C

Ochratoxin A (OA), when administered orally daily for 45 days to albino Swiss mice, Mus musculus, at a level equivalent to the human dietary concentration of 1 microgram/kg body weight/day, increased the production of abnormalities in both mitotic and meiotic chromosomes as well as in the gross morphology of the sperm head. The sperm count per unit volume of caput epididymal suspension also decreased. Vitamin C at a concentration equivalent to the human therapeutic dose (10 mg/kg body weight/day), when administered orally concurrently with OA, significantly minimized the incidence of these abnormalities. The protective effect of vitamin C was most marked in mitotic chromosomes followed by that in meiotic chromosomes and sperm head morphology; the improvement in sperm count was least marked. The possible mechanism of this effect is discussed.

Composition and behavior of head membrane lipids of fresh and cryopreserved boar sperm

Head plasma membranes were isolated from fresh or cryopreserved ejaculated boar spermatozoa and the lipids were extracted for determination of lipid fluidity (n = 6 for fresh and cryopreserved) and for compositional analysis (n = 5 for fresh, 6 for cryopreserved). Composition of the egg yolk extender was also determined. For fluidity determination, the mixed lipids were allowed to form natural liposomes. Bilayer fluidity of these liposomes was analyzed in the presence or the absence of 1 mM Ca2+ with the probes tPNA, which preferentially locates into gel-phase areas, and cPNA, which enters fluid and gel-phase areas equally and thus assesses bulk lipids. Fluidity of liposomes declined significantly during controlled-rate cooling for all samples. Compared to lipids from fresh membranes, gel lipids from cryopreserved cells lost fluidity at a significantly more rapid rate, as did bulk lipids in the presence of Ca2+ (P < 0.001). Fluidity increased during subsequent rewarming (5 to 50 degrees C), again at a slower rate for lipids from fresh cells, with the cryopreservation effect being significant for all probe/Ca2+ combinations (P < or = 0.05). Calcium altered the fluidity characteristics of membrane lipids from fresh but not cryopreserved sperm when analyzed during cooling with cPNA (P < 0.01) and during rewarming with cPNA (P < 0.0001) and tPNA (P < 0.05). Lipids from cryopreserved cells contained significantly less sphingomyelin (14.6 +/- 1.1 vs 22.4 +/- 1.6 mol%) and more phosphatidylcholine (51.5 +/- 2.0 vs 40.5 +/- 2.4%). The octadecanoate (18:0) content in both phosphatidylserine and phosphatidylethanolamine decreased after cryopreservation (P < 0.05). The polyunsaturated fatty acids docosatetraenoate (22:4) and/or arachidonate (20:4) increased in these phospholipids and in sphingomyelin and phosphatidylinositol (P < 0.05). The alterations in the molecular interactions, composition, and Ca2+ sensitivity of membrane lipids may interfere with the normal membrane events of fertilization.

[The effect of chemical mutagens on mammalian spermatogenesis. A cytogenetic analysis]

It was shown using the micronucleus test and estimating the defects of sperm heads that premeiotic and meiotic mammalian cells are genetically very sensitive to Dipin and nitrosomethylurea. In rats, unlike mice, the stem and differentiating spermatogonia with serious chromosomal defects are not eliminated and pass through a "sieve" of mitotic and meiotic divisions reaching the stage of round spermatids. Our observations suggest long-term preservation Dipin-induced, rather than nitrosomethylurea-induced, mutations in the stem cells of both mice and rats.

Effect of retinol on ochratoxin-produced genotoxicity in mice

Ochratoxin (1 microgram/kg body weight/day), when administered orally daily to albino Swiss mice for 14 continuous days, increased the incidence of abnormalities in mitotic and meiotic metaphase chromosomes, and the gross morphology of the sperm head; the sperm count per unit volume of caput epididymal suspension also decreased. These genotoxic effects were substantially reduced by concurrent oral administration of retinol at double the clinically therapeutic dose. It is possible that the electrophilic metabolites of ochratoxin form adducts with DNA or produce replacement-type mutations. Retinol may achieve its antigenotoxic effect by means of blocks and shunts in the ochratoxin metabolic pathway. Vitamin A-mediated cellular repair and scavenging of the mutagenic radicals can also take place. The vitamin itself has some genotoxic potential.