The Survival of Spermatozoa in Bovine Cervical Mucus and Mucus Fractions

Abstract

Summary. Bull spermatozoa survived at extremely low cell concentrations (10 to 470 cells/\g=m\l) at 37\s=deg\C in either cervical mucus or gel obtained by centrifugation of the mucus, but became immotile almost immediately after being suspended at 500 cells/\g=m\l in isotonic saline. Spermatozoa were adversely affected by suspension at low cell concentration in supernatant obtained by centrifuging mucus, or in mucus that had been liquefied by maceration. Although spermatozoa were slightly more resistant to the lethal effects of dilution in saline after passage through mucus, the resistance was quickly lost. The results suggest that the structural and physical properties of the mucus are responsible for the absence of the dilution effect on spermatozoa in cervical mucus.

Changes in ovine cervical mucus in response to oestrogen treatment

“…The physical nature of the cervical mucus varies greatly throughout the oestrous or menstrual cycle and plays a vital role in these functions (Mattner, 1969; Davajan, Nakamura & Kharma, 1970). An alteration of the physical properties of mucus by concurrent progestagen treatment of women (Elstein et al, 1976) or after prolonged exposure of ewes to oestrogenic pasture (Adams, 1976) leads to interference with sperm transport and reduces the likelihood of fertilization.…”

“…An alteration of the physical properties of mucus by concurrent progestagen treatment of women (Elstein et al, 1976) or after prolonged exposure of ewes to oestrogenic pasture (Adams, 1976) leads to interference with sperm transport and reduces the likelihood of fertilization. The physical properties of mucus are also believed to be responsible for its ability to maintain the viability of spermatozoa in vitro (Mattner, 1969).…”

Pregnancy rates in mares inseminated with 0.5 or 1 million sperm using hysteroscopic or transrectally guided deep-horn insemination techniques

“…Researchers studying the hydrodynamics of sperm motility have postulated an alternative hypothesis: they determined that the flagellar undulations of sperm induce motions in the fluid medium that move enzymes, ions, and other dissolved chemicals and gases to and from the plasma membranes of other sperm in close proximity, especially when sperm are within one body length from each other. As sperm concentration decreases, the distance between sperm is increased, which results in impaired exchange of the components within the liquid medium that are important to maintain sperm viability [60] The "dilution effect" has been described in multiple species including the rabbit [51,52,55,61], ram [52,54,57,61], bull [52,[56][57][58][62][63][64][65][66], boar [59], dog [53], stallion [67,68], and human [52,69]. In all these species, this phenomenon occurs when the neat semen in diluted to less than 20 million sperm/mL [51][52][53][54][55][56][57][58][59]61,65,66,69,70]; even though neat semen concentration [71], diluent type and seminal plasma concentration varies within species and individuals.…”

Nitric oxide increases endocervical secretion at the ovulatory phase in the female

“…Uterine cervical mucus is crucial for reproduction, facilitating sperm transport and survival in certain mammals (1,2). Cyclic structural changes in cervical secretion have been intensely studied and are correlated with fluctuations in serum levels of circulating ovarian hormones (1,2).…”