The Effects of Prostaglandins on Sperm Motility**Presented at the Thirty-Second Annual Meeting of The American Fertility Society, April 5 to 9, 1976, Las Vegas, Nev.††American Cystoscope Makers, Inc., Urology Prize Essay of 1976

Sperm motility and lipid composition in internally fertilizing ocellate river stingray Potamotrygon motoro

All extant groups of Elasmobranches have internal fertilization and the structure of the male reproductive organs is very specific: sperm passes from the internal organs via the cloaca, but the male copulating organ (clasper) is distant from the cloaca. This suggests that sperm can contact the surrounding medium before fertilization. Because of this involvement with the environment, external signaling in sperm motility activation could occur in these species even though their fertilization mode is internal. In this case, spermatozoa of Elasmobranches should hypothetically possess a specific structure and membrane lipid composition which supports physiological functions of the sperm associated with environmental tonicity changes occurring at fertilization. Additionally, sperm motility properties in these taxa are poorly understood. The current study examined sperm lipid composition and motility under different environmental conditions for the ocellate river stingray, Potamotrygon motoro, an endemic South America freshwater species. Sperm samples were collected from six mature males during the natural spawning period. Sperm motility was examined in seminal fluid and fresh water by light video microscopy. Helical flagellar motion was observed in seminal fluid and resulted in spermatozoon progression; however, when diluted in fresh water, spermatozoa were immotile and had compromised structure. Lipid class and fatty acid (FA) composition of spermatozoa was analyzed by thin layer and gas chromatography. Spermatozoa FAs consisted of 33 ± 1% saturated FAs, 28 ± 1% monounsaturated FAs (MUFAs), and 41 ± 1% polyunsaturated FAs (PUFAs), and a high content of n-6 FAs (32 ± 2%) was measured. These results allowed us to conclude that sperm transfer from P. motoro male into female should occur without coming into contact with the hypotonic environment so as to preserve potent motility. In addition, this unusual reproductive strategy is associated with specific spermatozoa structure and lipid composition. Low level of docosahexaenoic acid and relatively low PUFA/MUFA ratio probably account for the relatively low fluidity of freshwater stingray membrane and can be the main reason for its low tolerance to hypotonicity.

Effect of various concentrations of caffeine, pentoxifylline, and kallikrein on hyperactivation of frozen bovine semen

Caffeine, pentoxifylline, and kallikrein are substances that affect the efficiency of sperms in the fertilization process; however, they have not been adequately studied. The present study aimed to examine the influence of caffeine, kallikrein, and pentoxifylline on sperm motility in bovine as well as investigate their optimum concentrations for increasing the movement of sperms in bovine. Frozen bovine sperms were thawed in universal IVF medium supplemented with 1, 5, and 10 mM caffeine or pentoxifylline or 1, 4, and 8 U/mL kallikrein and were then incubated for 30 min. Treated semen parameters were analyzed using a computer assisted semen analyzer (CASA). Data analysis showed that the mean values concerning progression and motility of sperm increased in caffeine and pentoxifylline treatments when compared with the kallikrein group. The obtained results revealed that kallikrein is not necessary for the improvement of bovine sperm motility. Additionally, our results revealed that 5 mM from caffeine was the best concentration added to the medium, followed by 1 or 5 mM from pentoxifylline. Therefore, it is concluded from the present study that caffeine has hyperactivation efficacy at 5 mM concentration compared to other treatments.

Endogenous prostaglandin F2α concentrations in bovine whole semen, seminal plasma, and extended semen

A series of experiments were conducted to quantify PGF2α in bovine semen, seminal plasma, and extended semen, and to determine if PGF2α was synthesized or released during extension of bovine semen. Concentrations of PGF2α were measured in paired samples of whole and extended semen from beef and dairy bulls. Concentrations of PGF2α did not differ between beef and dairy (mean±SEM, 273.8±42.8 vs. 210.3±18.5 pg/mL, respectively; P=0.12), but tended (P=0.08) to be greater for whole compared with extended semen (255.5±29.8 vs. 194.5±17.0 pg/mL). Whole semen was extended at eight dilution rates (regardless of initial sperm concentration), using a diluent consisting of two fractions. Samples collected after each dilution step resulted in four subsamples. Concentrations of PGF2α in subsamples decreased (P<0.001) at higher dilution rates and later steps of extension. Subsequently, whole semen and seminal plasma were extended at three dilution rates. Initial PGF2α concentration was greater (P<0.001) for whole semen compared with seminal plasma. During extension, PGF2α synthesis or release resulted in less disparity, but the amount synthesized or released was greater (P=0.03) for semen compared with seminal plasma. We concluded that synthesis or release of PGF2α during extension resulted in concentrations similar to whole semen.

Functions of the seminal vesicle

The seminal vesicle is a gland which appeared late in the evolution of placental mammals. Vesiculectomy leads to very serious subfertility demonstrating the important role of this gland. Secretions of the seminal vesicle act during coitus and the maturation of the spermatozoon, on its mobility, its freezing capacity and the condensation of chromatin. These secretions also act on the female genital tract because they possess immunodepressive capacity. Due to their high concentration of prostaglandins, they can modify the contraction of smooth muscle. As shown by the animal model, they have an antibacterial role in the male genital tract. This explains the relatively low frequency of purely vesicular infections in human pathology.

In vitro effects of arecoline on sperm motility and cyclooxygenase-2 expression

Semen samples were obtained from 30 volunteers who had never consumed betel quid. Swim-up spermatozoa from the 30 seminal samples of non-betel quid chewers and also non-smokers, usually not exposed to passive smoking, were treated in vitro with arecoline at different concentrations to evaluate the action of these drugs on sperm motility. Highly motile sperms were collected and divided into 5 equal fractions. Four fractions were supplemented with various concentrations of arecoline and one as control. The study was carried out at time 0 and +1, +2, +3 and +4 hr of incubation. Sperm cells were also extracted and blotted with COX-2 antibody after arecoline treatment after 4 hr incubation. The sperm motility parameters, i.e., motility, average path velocity, curvilinear velocity, straight-line velocity and linearity, were significantly decreased after arecoline treatment. In vitro, arecoline induces the COX-2 expression of sperm cells in a dose-dependent manner. This is the first report to demonstrate that arecoline may mediate COX-2 expression in human sperms, resulting in inflammation response. This situation may act on the structure responsible for the flagellar motion and cause the reduction of sperm motility.

Activation of motility and chemotaxis in the spermatozoa: From invertebrates to humans

Activation of the sperm motility and chemotactic behavior of sperm toward eggs are the first communication between spermatozoa and eggs at fertilization, and understanding of the phenomena is a prerequisite for progress of not only basic biology, but also clinical aspects. The nature of molecules derived from eggs by which sperm are activated and attracted towards the eggs and the molecular mechanisms underlying the sperm activation and chemotaxis have been investigated in only a few invertebrate species, sea urchins, ascidians and herring fish. However, knowledge on this phenomena has been ignored in mammalian species including humans. The current review first introduces the studies on the activation and chemotaxis of sperm in marine invertebrates, and the same phenomena in mammals including humans, are described. (Reprod Med Biol 2005; 4: 101-115).

The Effect of Alcohol, Tobacco, and Aspirin Consumption on Seminal Quality among Healthy Young Men

In this study, the authors examined the effects of alcohol, tobacco, and drug use on plasma testosterone and seminal parameters (in accordance with the World Health Organization's standards) in healthy Argentine medical students (n = 34). Some alterations in seminal parameters were detected in 19 (56%) subjects. Alcohol and tobacco use were correlated significantly, p = 0.005; subjects who used these substances exhibited a nonsignificant reduction in sperm concentration, motility, viability, and normal morphology. There was a significant decrease in sperm motility among students who used moderate amounts of aspirin (i.e., > or = 500 mg/wk). The authors concluded that alcohol, tobacco, and aspirin use could have had detrimental effects on seminal parameters and that men who wish to procreate should be warned of such effects. Doses, exposure time, and interactions with other variables deserve additional study.

Localization of COX-2 in the male reproductive tract during sexual maturation

Prostaglandins (PGs) are shown to influence sperm motility, contractility of the smooth muscle layers surrounding the seminiferous tubules and growth of both the seminal vesicle and the ventral prostate. PGs are produced by two distinct isoforms of cyclooxygenase (COX), including constitutively expressed COX-1 and inducible COX-2. To investigate the potential role of COX-2 in male reproductive tract maturation, we evaluated its expression in rats at pre-pubertal (14 days old), peri-pubertal (21, 28 and 35 days old) and post-pubertal (62 days old) stages. COX-2 was constitutively expressed in the initial segment of the epididymis, caput epididymidis and vas deferens at all stages of maturation. Its expression was mild in 14-day-old rats but its intensity markedly increased at 28 days and remained elevated afterwards. There was no COX-2 staining in the testis, rete testis, efferent ducts or cauda epididymidis. These data suggest that COX-2 derived PGs may be involved in the pubertal development of the epididymis, but not in the more apical regions of the excurrent duct system, including the rete testis and efferent ductules.

Functional activity of mouse sperm was not affected by low doses of aspirin-like drugs

To investigate some possible effects of low doses of nonsteroidal anti-inflammatory drugs upon functional activity of mouse sperm, the authors injected lysine acetyl salicylate (im 14.3 mg/kg day(-1), ibuprofen (ip 5.6 mg/kg day(-1)), or piroxicam (ip 0.28 mg/kg day(-1) to pregnant females (the male cohort was sacrificed at adulthood) (A) or to adult males during 35 (B) or 60 (C) days. Parameters measured were motility, viability, acrosomal integrity, responses to hypoosmotic shock, in vitro fertilization index, and testosterone plasma levels. Salicylate evoked a slight reduction in the percentage of swollen gametes in A, and ibuprofen diminished testosterone plasma levels in B. The other parameters remained unchanged in all groups. Results are well supported by the low doses assayed, which are equivalent to the content of one tablet commercially available for each compound.

Effects of added caffeine on results following artificial insemination with fresh and refrigerated rabbit semen

Lactating rabbits (n=1335) were artificially inseminated to study the effect of the addition of caffeine on rabbit semen stored for up to 96 h. Concentration of 0-5 mM/l were tested. Whereas a concentration of 0.2 mM/l increased spermatozoa motility, higher concentration values adversely affected reproductive parameters. Spermatozoa stored at 18 degrees C for 72-96 h did not have the capacity to react with caffeine when it was added before insemination. Caffeine did not enhance fertility or prolificacy, regardless of its ability to increase sperm motility.

Mouse spermatozoa can synthesize PGE2 and 5-HETE in vitro: stimulatory action of nitric oxide

Cauda epididymal spermatozoa were examined for their capacity to synthesize prostaglandins (PGs) and hydroxy acids and the role of nitric oxide (NO) on cyclooxygenase and lipoxygenase enzyme activity was determined. Sperm suspensions were incubated in the presence or absence of 300 microM sodium nitroprusside (NP) and 20 micrograms/ml hemoglobin (Hb) and then incubated with [14C]arachidonic acid (AA) for 60 min. The cyclooxygenase and lipoxygenase products of AA metabolism were measured for their radioactivity. It was found that mouse spermatozoa could synthesize PGE2 and 5-hydroxyeicosatetraenoic acid (5-HETE) under these experimental conditions. The synthesis of these two metabolites was 100% stimulated by NP, the releaser of NO, and the response to NP was completely prevented by Hb, a scavenger of NO. These data provide evidence that mouse spermatozoa can synthesize PGE2 and 5-HETE in the presence of AA in vitro and that NO is involved in the production of AA metabolites in the male gamete.

Influence of thymosin on the level of cyclic nucleotides in rats with experimental varicocele

Experimental varicocele was induced by partial ligation of the left renal vein in rats, and the effect of thymosin (fraction 5), a hormone secreted by the thymus, on the level of cyclic nucleotides was investigated. The levels of cAMP and cGMP in plasma and testicular tissue were estimated using radioimmunoassay techniques. The results showed that the level of cAMP in bilateral testicular tissues in rats with experimental varicocele decreased considerably, especially in the left testicular tissue as compared with that in the control group (P < 0.05). 4 weeks after thymosin administration (0.5 mg/rat, twice a week), the level of cAMP in bilateral testicular tissues rose significantly, as compared with that in the experimental varicocele group (P < 0.01). These findings indicate that there exists imbalance in the metabolism of cyclic nucleotides in rats with experimental varicocele. This suggests that the abnormal level of cyclic nucleotides is one of the causes of infertility with varicocele. Since thymosin participates in the metabolism and regulation of cyclic nucleotides, it may have a direct or an indirect effect on the growth and function of reproductive cells.

Immunohistochemical localization of PGF2 alpha receptor in the mouse testis

As a step towards understanding the role of prostaglandin F2 alpha (PGF2 alpha) in male reproductive tract physiology, a rabbit polyclonal antiserum reactive with purified PGF2 alpha receptor (PGF2 alpha-R) was produced. Here we describe the use of this anti-PGF2 alpha-R antiserum in immunohistochemical staining of mouse testis to ascertain which cell types, in vivo, possess immunoreactive PGF2 alpha-R. As an initial control Western blot analysis was performed to show that the anti-PGF2 alpha-R antiserum recognizes only one antigen in the testis, and that this molecule is similar in molecular mass (by PAGE) to the previously described, purified PGF2 alpha-R molecule. Immunohistochemical staining demonstrates that adult mouse testis contains a single subpopulation of cells with PGF2 alpha-R and that subpopulation is the interstitial or Leydig cell subpopulation. Cell and tissue types negative for immunoreactive PGF2 alpha-R include: the capsule (tunica albuginea) and subcapsular stroma, all histologic layers of the vasculature (both venules and arterioles), peritubular stroma, peritubular boundary tissue, spermatogonia, primary and secondary spermatocytes, spermatids, Sertoli cells, and spermatozoa. While the above described localization of PGF2 alpha-R is also seen in rat, there are fewer rat Leydig cells and this subpopulation appears to atrophy and stain less intensely with increasing age of the animal. Preabsorption of the PGF2 alpha-R antiserum with a corpora lutea homogenate acetone powder eliminated immunohistochemical staining of the Leydig cell subpopulation further suggesting that the antigenic determinant detected here is related to that in the ovary (PGF2 alpha-R).

Effect of peritoneal fluid on sperm motility and velocity distribution using objective measurements

The aim of this study was to analyze in vitro the effect(s) of peritoneal fluid (PF) on sperm motility. Seventy PFs obtained during laparoscopy were tested on motile-rich sperm suspensions. Proportion of motile sperm and velocity distribution were evaluated by multiple-exposure photography technique. At time (t) = 0, PFs increased both sperm parameters as compared with control (P less than 0.01). Maximum effect was observed at t = 5 hours: 32 (45%) PFs increased and 5 (7%) decreased the proportion of motile sperm, while 8 (11%) PFs increased and 4 (6%) decreased sperm velocity. No correlation was found between a particular infertile group and a definite negative effect. However, 70% of PFs from fertile women maintained or increased the proportion of motile sperm at t = 5 hours, compared with 36% in the total infertile group. Comparison of the sperm motility effect(s) of a given PF on different ejaculates revealed that the effects observed also were influenced by the sperm sample tested. In conclusion, PFs can maintain or increase the motility of spermatozoa as function of time. However, some PFs can inhibit sperm motility and these effect(s) can be influenced by the sperm sample.

Analysis of the role of prostaglandins in the fertilization process

This study was designed to elucidate the role of prostaglandins (PG) in the fertilization process, using indomethacin (ID), an inhibitor of PG biosynthesis, and mouse in vitro fertilization as a model for analysis. Spermatozoal viability, as assessed via motility, was not suppressed by ID at 100 and 150 micrograms/ml in 3-h incubation, but markedly by 200 micrograms/ml in 1-h incubation. On the other hand, ovum viability was not affected even by 200 micrograms/ml ID in 5-h incubation, as assessed via dye-excretion and morphology. Fertilization rates for 0, 100, 150 and 200 micrograms/ml ID were 58.8, 54.8, 24.3 and 18.9%, respectively; at 150 micrograms/ml and more, significant inhibition was noted. The reduction in spermatozoal viability at 200 micrograms/ml ID was not detected after supplementation of 50 micrograms/ml PGF2 alpha. Fertilization rates were 23.1 and 20.7% in the groups at 150 and 200 micrograms/ml ID with PG solvent, respectively. After supplementation of 50 micrograms/ml PGF2 alpha, the rates were 55.8% and 64.0%, respectively. The degenerated eggs significantly increased. The polyspermic eggs also tended to increase in the ID 200 micrograms/ml groups; however, after PGF2 alpha supplementation, the number of such eggs tended to decrease. Based on these facts, it is concluded that PG may play their role in fertilization not only via sperm, but also via eggs.

Effect of prostaglandins on human sperm function in vitro and seminal adenosine triphosphate content

The aim of the present study was to evaluate the effect of addition of physiologic amounts of different prostaglandins normally present in semen, on sperm motility, on sperm penetration capacity in cervical mucus in vitro, and on the adenosine triphosphate (ATP) concentration in semen. Semen samples were obtained from volunteers who were attending the fertility outpatient clinic. Sperm motility was measured on a video recorder with a built-in timer, sperm penetration by the Kremer test, and ATP by bioluminescence assay. The addition of 19-hydroxy prostaglandin (PG) E to ejaculates positively stimulated sperm motility and sperm penetration capacity. The opposite effect was observed with 19-hydroxy PGF. PGE1, PGE2, and PGF2 alpha had no effect on either parameter, while PGF1 alpha reduced the sperm motility. The addition of 19-hydroxy PGE to ejaculates increased and the addition of 19-hydroxy PGF reduced semen concentrations of ATP. However, only the last-mentioned effect was statistically significant (P less than 0.05). It is suggested that, in particular, 19-hydroxy PGE and 19-hydroxy PGF are important regulators of sperm motility and that the effect may be mediated via effects on the ATP content in the spermatozoa.

Prostaglandin levels in infertile patients affected by asthenozoospermia and prostatitis

19-hydroxy-prostaglandins and prostaglandins of the E series (19-OH PGEs) were estimated in the seminal plasma of asthenozoospermic patients (n = 15) and individuals affected by prostatitis (n = 10) and compared to controls (n = 13) and secretory azoospermic patients (n = 8). All of them were free from infections (except individuals affected by prostatitis), biochemical and ultrastructural problems. The results indicate that endogenous prostaglandin levels (19-OH PGEs and PGEs) bear no correlation either to motility or absence of spermatozoa. Significant increases of PGEs were observed in patients affected with prostatitis. Surprisingly PGE levels showed no correlation with the levels of 19-OH PGEs.

Seminal prostaglandins in men with subnormal sperm motility and therapeutic treatment

The contents of prostaglandins in seminal plasma from a total of 73 men were evaluated. The subjects were grouped as follows: normospermic men, patients with impaired motility, patients with small untreated varicocele and patients with impaired motility and Kallikrein therapy. Sperm density, morphology and motility were examined. High performance reversed phase liquid chromatography (HPLC) in combination with specific radioimmunoassays were used for the determination of PGE2, PGI2 and PGF2 alpha. There was a significant difference (p less than 0.025; F-test) between the PGI2 concentrations in patients with impaired motility (5.6 +/- 1.4 pg/mg protein) and normal men (8.8 +/- 3.7 pg/mg protein). PGE2 and PGF2 alpha were significantly different in patients with varicocele (p less than 0.025, F-test). Wide ranges of prostaglandins occurred in the Kallikrein-group with no significant differences. We conclude that: a) PGI2 is an additional prostaglandin compound in seminal plasma, b) its measurement may not be useful as diagnostic parameter in subfertile men and c) Kallikrein has no influence on the prostaglandin content in seminal plasma and other seminal parameters as motility, motility index and sperm counts.

The prostaglandin inhibitor effect of antiinflammatory drugs in the therapy of male infertility

The effects of various doses of indomethacin and ketoprofen as compared with placebo were examined in 100 oligospermic patients who participated in this study. It was found that the treatment increased sperm count, sperm motility, and fertilizing capacity. The radioimmunoassay examination showed an increase in plasma follicle-stimulating hormone and luteinizing hormone but a decrease in testosterone. The results show that the influence of indomethacin was better in the dose of 75 mg daily. The mechanism of those changes is not clear. Treatment should be at least 60 days.

Comparison of the inhibitory action of delta-9-tetrahydrocannabinol and petroleum spirit extract of herbal cannabis on human sperm motility

1 Using the trans-membrane migration method to measure drug effects on human sperm motility, it is found that delta-9-tetrahydrocannabinol is the major constituent of cannabis which inhibits sperm motility and unlike the cataleptic effect, other constituents in the petroleum spirit extract do not potentiate this effect significantly. 2 It is suggested that the mechanisms for sperm immobilization and cataleptic effects are different.

Prostaglandins and cyclic-AMP in human semen

Normospermic, oligospermic and azoospermic semen samples were analysed for prostaglandins of the E groups and for cyclic AMP. The whole procedure was rapidly performed in a nitrogen atmosphere. Higher levels of total PGEs (PGEs+19-hydroxy PGEs) were found in normospermic (135.6 micrograms/ml) than in either oligospermic or azoospermic semen. The average level of cyclic AMP in normospermic semen (32.0 nmole/ml) did not differ significantly from the test groups, but very low levels were found only in oligo and azoospermic semen. The correlation coefficient between cyclic AMP and total-PGE concentrations was +0.36. The correlation coefficient between cyclic AMP level and percentage of motile sperm cells was +0.56 (p less than 0.0005). Patients who were treated for two months with a daily dose of 50mg clomiphene citrate exhibited significant elevation of cyclic AMP in their seminal fluid. This finding suggests that cyclic AMP is important for sperm motility and that the clomiphene effect on human semen may be mediated by cyclic AMP.

The influence of prostaglandins on sperm motility

Prostaglandin E2 and F2 alpha were measured in ejaculates from 10 fertile and 55 infertile men. Prostaglandin F2 alpha was negatively correlated with motility (r = 0.77; p less than 0.01) in normal men. In patients with disturbed fertility, prostaglandin F2 alpha was always higher than in the controls, while prostaglandin E2 was elevated only in patients with persisting varicocele and in those with very low sperm counts and severely impaired motility. There was neither de novo synthesis of prostaglandins in spermatozoa nor were binding sites for prostaglandin E2 and F2 alpha detectable. Inactivation of seminal prostaglandins by incubation with prostaglandin 15-hydroxydehydrogenase resulted in a dramatic fall in motility. The results suggest that prostaglandin F2 alpha act on motility, but the action is not mediated by receptors.

Assay of progressive motion of boar spermatozoa

The motility of ejaculated boar spermatozoa was assayed by measuring the number of organisms which have entered a capillary tube in an experimental setup with the spermatozoal suspension as well as the capillary content containing the same chemically defined motility medium. This medium, used both for washing and suspending spermatozoa, contained only an isotonic tris HCl (isotris) buffer at pH 7.0. The recommended assay conditions are the following: (1) wash the spermatozoa three times with isotris buffer, (2) suspend the spermatozoa in a concentration of 10(6) spermatozoa/ml, and (3) assay at 25 degrees C with an incubation period of 60 min.

Effects of prostaglandins E-1, E-2, F-1a and F-2a on human sperm motility

Effects of the addition of 100 micrograms each of prostaglandins E1, E2, F1a and F2a were seen on the motility, fructose utilization and total ATPase activity of human spermatozoa. PGE2 enhanced sperm motility and fructose utilization and decreased the whole sperm ATPase activity. While PGE1 had no effect on any of the parameters studied, PGF1a and PGF2a decreased sperm motility to some extent. Fructose utilization was reduced after PGF1a addition only. No change in the activity of ATPase was observed after treatment with F series of prostaglandins.

Effect of p-nitrophenylglycerol on motility of rat epididymal spermatozoa

Using a convenient capillary tube assay, the antiswarming agent acting on Proteus, p-nitrophenylglycerol (PNPG), was found to have produced an antimotility effect in sperms from rat cauda epididymides.

Spermatozoa repellent as a contraceptive

Early report by Kopp et al. have demonstrated that p-nitrophenyl-glycerol (PNPG) is an effective antiswarming agent in Proteus and that this inhibition may have been caused by PNPG interfering with the negative chemotaxis mechanism in the organism. With an inverted capillary assay, designed to test the motility response of rat epididymal spermatozoa to various suspending conditions including those exposed to chemical gradient, PNPG was shown in this study to exhibit an inhibitory effect at slightly higher than 10(-5) M. Moreover, this inhibitory effect appears to have stemmed from spermatozoa being repelled by PNPG as indicated by the observation that significantly less spermatozoa swim into a gradient of PNPG. The possibility of using spermatozoa repellents as contraceptives is discussed.

The effects of fenclozic acid on fertility of male rats

Fenclozic acid, a prostaglandin synthesis inhibitor, was administered to male rats by stomach intubation. A second group of rats received the vehicle (1% methylcellulose) alone. The dose schedule used was 75 mg/kg on day 1, 50 mg/kg on day 2 and 25 mg/kg on days 3, 4 and 5. The dose was progressively reduced to eliminate the toxic effects seen in the initial stages of the treatment. All the animals had normal fertility and libido before treatment and during administration of the vehicle. However, sterility or subfertility was seen in 4 of the 6 animals treated with fenclozic acid. Sperm were always present in the vaginal smears. It was concluded that the reduction in fertility was probably caused by an effect of the drug on maturation or metabolism of the sperm.

Insemination of husband's semen with and without the addition of caffeine

Four hundred cervicovaginal artificial inseminations using husband's semen were carried out for a variety of clinical indications. Before insemination, to one-half of the samples caffeine was added to a final concentration of 6 mM. Although the motility of the spermatozoa was enhanced in each case, no pregnancies were achieved. Of the four pregnancies in the series, only one could be attributed to artificial insemination.

Interference of human spermatozoal motility by trichomonas vaginalis

Human spermatozoa were exposed to concentrations of live Trichomonas vaginalis varying from 10(4) to 10(7) organisms per ml. A striking decrease in spermatozoal motility ensued. The possible role of trichomoniasis in human reproductive failure is considered.