A quantitative determination of the content of contractive substances in human sperm and their significance for the motility and vitality of the spermatozoa

Arachidonic Acid Pathways and Male Fertility: A Systematic Review

Arachidonic acid (AA) is a polyunsaturated fatty acid that is involved in male fertility. Human seminal fluid contains different prostaglandins: PGE (PGE₁ and PGE₂), PGF_2α, and their specific 19-hydroxy derivatives, 18,19-dehydro derivatives of PGE₁ and PGE₂. The objective of this study is to synthesize the available literature of in vivo animal studies and human clinical trials on the association between the AA pathway and male fertility. PGE is significantly decreased in the semen of infertile men, suggesting the potential for exploitation of PGE agonists to improve male fertility. Indeed, ibuprofen can affect male fertility by promoting alterations in sperm function and standard semen parameters. The results showed that targeting the AA pathways could be an attractive strategy for the treatment of male fertility.

Vaginal misoprostol enhances intrauterine insemination

This study examined whether the prostaglandin E(1) analogue misoprostol (400 microgram), when placed vaginally at the time of intrauterine insemination (IUI) improves pregnancy rates. A prospective, placebo-controlled, randomized and double-blind study involving 274 women in 494 IUI cycles resulted in a total of 64 pregnancies (13% per cycle). Misoprostol cycles totalled 253, with 43 pregnancies (17% per cycle), whereas placebo cycles totalled 241, with 21 pregnancies (9% per cycle). The cumulative pregnancy rate with misoprostol treatment was significantly greater than with placebo (P = 0.004, Cox proportional hazards regression). The benefit of misoprostol was seen in clomiphene cycles (14 versus 4%, P = 0.006), and was indicated in FSH cycles (33 versus 15%, borderline significance) and natural cycles (15.6 versus 7.7%, not significant), but was not seen in clomiphene/FSH cycles (18.2 versus 23.5%, not significant). Misoprostol treatment did not increase pain score on the day of IUI (1.1 versus 1.4) and at 1 day post IUI (0.6 versus 0.8). Complications were rare in both groups [six (2%) subject cycles in the misoprostol cycles compared with two (1%) in the placebo group]. It is concluded that the use of vaginal misoprostol may improve the chance for pregnancy in women having IUI in a wide variety of cycle types.

On the question of the occurrence and metabolism of 5-hydroxytryptamine and related indole compounds in mammalian semen

The content of 5-hydroxytryptamine was examined in the semen of man, bull, ram, boar and dog. Spectrophotofluorimetric and chromatographic analysis of extracts prepared by several methods has shown that the semen contains only minute quantities of 5-hydroxytryptamine, if any. One cannot attribute to 5-hydroxytryptamine the uterus-stimulating effect which the human seminal plasma is known to exert. Tryptophan, although present in the seminal plasma, is not converted to 5-hydroxytryptamine on incubation of semen. 5-Hydroxytryptophan is oxidatively deaminated, but not decarboxylated, by spermatozoa. 5-Hydroxytryptamine itself, like tryptamine and tyramine, is not deaminated by either whole semen or washed suspensions of ram spermatozoa.

THIN-LAYER CHROMATOGRAPHY AND BIOASSAY OF PROSTAGLANDINS IN EXTRACTS OF SEMEN AND TISSUES OF THE MALE REPRODUCTIVE TRACT

By acid ether extraction and thin-layer chromatography, prostaglandins have been separated from biologically active compounds of other chemical groups. The technique does not, however, separate different prostaglandins from each other. The biological activity of the eluates was estimated on the rabbit isolated jejunum and the hamster isolated colon preparations in terms of prostaglandin E(1); the concentrations (thus expressed) of prostaglandin in human semen ranged from 24 to 783 mug/ml. with a mean of 226 mug/ml. No prostaglandins (minimal detectable concentration, 0.5 mug/g) could be detected in the male reproductive organs of several species of laboratory animal.

Aberrant uterine response to prostaglandin E2 as a possible etiologic factor in functional infertility

The clinical entity of functional infertility still remains unexplained and largely lacking a line of proper management. The uterine response to prostaglandin E2 (PGE2) and prostaglandin F2alpha (administered by intravenous and intrauterine routes) was evaluated during different phases of the menstrual cycle in five functionally infertile women. The results (quantitative and qualitative) were compared with those elicited among 20 fertile women. There were no apparent differences between the two groups with respect to either compound (systemic or local) when given during the proliferative or luteal phase of the cycle. However, at midcycle, about the time of ovulation (days 13 to 18), there was a salient deviation in the type of response following local instillation of PGE2; in the normal fertile group there was a definite inhibition of motility, while uteri in the functionally infertile group showed marked stimulation. The possible role of this aberrant uterine response in the etiology of functional infertility is discussed.