Biochemical Aspects of the Coagulation and Liquefaction of Human Semen

Abstract

The coagulation and liquefaction process of human semen was studied in some detail. It was found that contact of seminal vesicle fluid with the other accessory sex gland secretions or spermatozoa does not seem to be essential for the formation of the coagulum, and that heparin and sodium citrate do not affect coagulum formation, indicating a difference between the seminal coagulation process and that of the blood clot. Regarding the liquefaction process of the seminal coagulum, it was shown that 1) spermatozoa do not influence liquefaction; 2) that the seminal plasminogen activator, lysozyme, α‐amylase, pepsin, and neuramini dase are not the primary liquefying factors; 3) that the liquefying agent is present in the first portion of a split ejaculate, is heat labile, is partially destroyed by freezing at −20 C but is stable to lyophilization, is precipitable with (NH4)2SO4, is not affected by serum or EDTA, and is inhibited by rabbit bile but not by the seminal plasma proteinase inhibitors, the Kunitz pancreatic trypsin inhibitor, or epsilon‐aminocaproic acid (EACA). All of these prop erties are characteristics of the seminal en zyme, seminin. A partially purified preparation of this enzyme enhanced liquefaction, and two patients who had low seminin activity pos sessed poorly lysing coagula. These findings confirm that seminin is the agent primarily re sponsible for liquefaction of the seminal coagulum of man. The data further show that liquefaction of the seminal coagulum occurs by a different mechanism than that of the lysis of the blood clot.

Influence of ejaculation frequency on semen characteristics in chimpanzees (Pan troglodytes)

“…On the other hand, the liquefaction process is induced by factor(s) contained in the first portion of a split ejaculate consisting mainly of prostatic secretion (Tauber et al, 1980). In the present study, the percentage of liquefaction of the ejaculate was positively correlated with citrate and acid phosphatase concentrations, of prostatic origin, but negatively correlated with concentration of fructose, from seminal vesicles.…”

Feasibility of sex-sorting sperm from the white and the black rhinoceros (Ceratotherium simum, Diceros bicornis)

“…Upon ejaculation, spermatozoa are mixed with secretions from the accessory sex glands, entrapping the spermatozoa in a highly viscous gel (unpublished observations). Spermatozoa cannot be separated from the gelatinous material by filtration or centrifugation as routinely applied in the boar or the stallion, nor does the gel fraction liquefy after a short period of time (human [17]) or release spermatozoa by contraction (rhesus monkey [18]). These limitations are also evident in the semen samples of camelids such as the alpaca and llama [19,20].…”

Evolution of the Hominoid Semenogelin Genes, the Major Proteins of Ejaculated Semen

“…Immediately upon ejaculation, human semen coagulates to form a gelatinous viscous mass, which then liquefies within 20 min by the proteolytic degradation of the semenogelins by the prostate-derived human kallikrienen 3 enzyme (hK3), also known as the prostate specific antigen (PSA) (Tauber et al 1980;Lilja et al 1987). At least 60% of the volume of the ejaculated semen is derived from the seminal vesicles, with about 30% from the prostate, and the remainder from the testes, epididymis, and minor accessory sex glands (Mortimer 1993).…”