Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.

Movement characteristics and acrosomal status of rabbit spermatozoa recovered at the site and time of fertilization.

Abstract: Rabbit spermatozoa were recovered from the oviductal ampullae 11 h postcoitus by an oil microflush technique. Their movement was evaluated in the ampullar fluid, or in ampullar fluid diluted with in vitro fertilization medium, in slide preparations which were approximately 25 micron or 100 micron deep. The movement of these sperm was compared with the movement of ejaculated sperm in diluted semen. Movement parameters measured from videotapes recorded by a high-speed camera were coded according to treatment and entered into a microcomputer for statistical analysis. A total of 157 spermatozoa were recovered from the oviducts of 16 does: 152 were motile and 126 were free-swimming. Nearly all of the free-swimming sperm swam in trajectories whose average paths were circular. The flagellar beat pattern of the circular swimmers was asymmetric and nearly planar, and the sperm did not roll. Spermatozoa observed in 25-micron slide preparations produced smaller flagellar bends than sperm swimming in 100-micron preparations and tended to swim in larger circles which were oriented in the plane of the slide. Spermatozoa observed within the cumulus matrix moved in a slow, erratic, sinuous manner, but resumed rapid circling upon leaving the matrix. It was concluded that the ampullar sperm were hyperactivated, retaining this physiological condition as they entered the cumulus. The movement qualitatively resembled that of hyperactivated guinea pig and hamster spermatozoa because these species effectively swim in circles. In contrast, 80% of the ejaculated spermatozoa swam in linear trajectories, resulting from relatively symmetrical, flagellar beat patterns. The percentage of rolling spermatozoa and the rolling frequencies were less in the 25-micron than the 100-micron slide preparations. Thus, the movement parameters of both ampullar and ejaculated spermatozoa were affected by the geometry of their observation chambers. This influence should be taken into account when observing sperm motility in vitro. It could also be important in vivo, where changes in sperm movement in response to epithelial surfaces might provide an advantage for reaching the cumulus mass. Ninety-eight percent of the motile ampullar sperm were observed to have acrosomes, including all spermatozoa found within the cumulus matrix.

Semen-induced ovulation in the bactrian camel (Camelus bactrianus).

Abstract: Bactrian camels (63 female female, 8 male male) were used in the breeding season to determine the factors that will induce ovulation. After insemination of semen samples into the vagina, the ovaries were checked for ovulation by rectal palpation. The results indicated that ovulation was induced by the seminal plasma, but not by the spermatozoa, and the incidence of ovulation after insemination was 87%. Most of the females (66%) had ovulated by 36 h after insemination and the rest by 48 h, as after natural service. The least amount of semen required to elicit ovulation was about 1.0 ml. Intramuscular injections of LH, hCG and LHRH also caused ovulation, even in females that had not ovulated in response to insemination.

Analysis of human sperm function following exposure to the ionophore A23187. Comparison of normospermic and oligozoospermic men.

Abstract: Time exposure photomicrography and interspecific in vitro fertilization techniques have been used to compare the responses to the divalent cation ionophore A23187 of spermatozoa from normal fertile and oligozoospermic men. The fertilizing capacity of spermatozoa from the fertile controls produced a bell-shaped dose response curve when assessed in the presence of ionophore. The optimal responses occurred in the presence of 50 and 100 microM A23187. At this concentration, a mean penetration rate of about 75%, in association with multiple polyspermy, was observed without significant changes in motility patterns. At higher doses of A23187, there was a decline in fertilization rates, an independent reduction in sperm motility, and a significant decrease in the amplitude of lateral sperm head displacement. In contrast to the fertile controls, spermatozoa recovered from patients with oligozoospermia failed to exhibit a significant change in their fertilizing potential following exposure to A23187. Calculations based on the Poisson distribution theory indicated that this lack of responsiveness was not related to any differences in the motility of the spermatozoa from the oligozoospermic patients compared to the controls. These results suggest that calcium ionophores may be of value in providing a rapid and sensitive indicator of the functional competence of human spermatozoa, which circumvents problems concerning the rate and efficiency of sperm capacitation encountered with conventional protocols.

Relationship between acrosin activity of human spermatozoa and oxidative stress.

Abstract: Aim To study the association between seminal oxidative stress and human sperm acrosin activity. Methods It is a prospective study consisting of 30 infertile men and 12 fertile normozoospermic volunteers. A full history, clinical examination and scrotal ultrasound were done to exclude other related factors such as smoking and varicocele. Presence of white blood cells (WBCs) in semen samples was evaluated by peroxidase staining. Lipid peroxidation in spermatozoa was induced after incubating with ferrous sulphate (4 mmol/L) and sodium ascorbate (20 mmol/L). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS). Acrosin activity was measured using the gelatinolysis technique. The halo diameters around the sperm heads and the percentages of spermatozoa showing halo formation were evaluated. An acrosin activity index was calculated by multiplying the halo diameter by the halo formation rate. Results A significant difference was observed in acrosin activity parameters and TBARS levels between samples with WBCs (1 multiply 10(6)/mL of ejaculate) and those without. This difference was also noted between the normozoospermic and the oligoasthenoteratozoospermic semen samples. The TBARS production by spermatozoa had a significant negative correlation with the acrosin activity index (r = -0.89, P 0.001). Conclusion The presence of oxidative stress in an individual with leukocytospermia and/or abnormal semen parameters is associated with impaired sperm function as measured by its acrosin activity.