Whither must spermatozoa wander？ The future of laboratory seminology

This commentary celebrates the publication of the 5th for the Examination and Processing of Human Semen edition of the World Health Organization Laboratory Manual This is the most complete text to date on the creation of a conventional semen profile and includes invaluable reference limits for specific aspects of semen quality based on the analysis of over 1 900 recent fathers. The new edition of the manual also includes detailed protocols for monitoring different aspects of sperm function and new chapters on the preparation of spermatozoa for assisted conception and cryopreservation. Given that this publication is the definitive statement on how to perform a descriptive semen analysis, we might speculate on the future of this field and the sorts of tests that might feature in future editions of the manual. Cell biologists are currently being empowered by the ＇omics revolution, which is placing at their disposal technologies of unprecedented power to examine the biochemical composition of cells such as spermatozoa. Indeed, spermatozoa are perfect vehicles for this kind of analysis because they can be obtained as extremely pure suspensions, exist naturally in isolation and can be induced to express their capacity for fertilization and the initiation of embryonic development in vitro. The application of ＇omics technologies to these cells, in concert with detailed assessments of their functional competence, should provide insights into the biochemical basis of defective semen quality. This information will then help us understand the causes of male infertility and to develop rational methods for its treatment and possible prevention.

Evidence that chronic hypoxia causes reversible impairment on male fertility

Aim： To evaluate the effect of chronic hypoxia on human spermatogenic parameters and their recovery time. Methods： Seminological parameters of six male healthy mountain trekkers were evaluated in normoxia at sea level. After 26 days exposure to altitude （ranging from 2 000 m to 5 600 m, Karakorum Expedition） the same parameters were again evaluated after returning to sea level. These parameters were once again evaluated after 1 month and then again after 6 months. Results： Sperm count was found to be lower immediately after returning to sea level （P = 0.0004） and again after a month （P = 0.0008）. Normal levels were reached after 6 months. Spermatic motility （%） shows no reduction immediately after returning to sea level （P = 0.0583）, whereas after 1 month this reduction was significant （P = 0.0066）. After 6 months there was a recovery to pre-hypoxic exposure values. Abnormal or immature spermatozoa （%） increased immediately after returning to sea level （P = 0.0067） and then again after 1 month （P = 0.0004）. After 6 months there was a complete recovery to initial values. The total number of motile sperm in the ejaculate was found to be lower immediately after returning to sea level （P = 0.0024） and then again after 1 month （P = 0.0021）. After 6 months there was a recovery to pre-hypoxic exposure values. Conclusion： Chronic hypoxia induces a state of oligospermia and the normalization of such seminological parameters at the restoration of previous normoxic conditions after 6 months indicate the influence of oxygen supply in physiological mechanisms of spermatogenesis and male fertility.