Anticomplementary Activity in Human Semen and Its Possible Importance in Reproduction

Abstract

We demonstrated anticomplementary activity on once-washed human sperm, and in normal and vasectomized seminal plasmas. It was demonstrated to be a normal component of human semen. The origin of the activity is proposed to be the seminal plasma with sperm adsorption of activity. The properties of the seminal anticomplementary factor were characterized further, and the molecular size was shown to be less than 3500 daltons. Reduced anticomplementary activity was found to be associated significantly with abnormal semen profiles and infertility in males. The activity in seminal plasma was shown to have no effect on complement-dependent sperm immobilizing antibodies in the serum of an infertile woman, implicating an effect on the post-C3 components of the complement pathway. The inhibition of complement-dependent haemolysis and the lack of inhibition of complement-dependent sperm immobilization by the anticomplementary factor are considered in the implications of the role of seminal anticomplementary activity in reproduction.

Immunosuppressant Material in Human Seminal Fluid

“…When this material was added to assay systems such as rosette formation [5], induced blast transformation [11], cell activity [12], and mononuclear-cell adherance [13], the activi ties were severely reduced. The inhibitory activity of human semen was shown to affect the complement activity [14,15]. In vitro the inhibitory activity was also demon strated by several authors in an animal sys tem [16].…”

Naturally-occurring antisperm antibodies in men: interference with fertility and clinical implications. An update

“…An antibody effect on semen quality should involve a complement mediated sperm cytotoxicity occurring within the male genital tract. However, anticomplementary activity has been reported in human semen (23,24), and it was recovered in the low molecular weight of the seminal plasma (20-60,000 Daltons) using gel filtration chromatography (23). This fraction inhibited total complement activity as well as the activity of the early C components C1 and C3.…”

Anticomplement Activity in Human Aqueous Humor

“…The samples were inactivated at 56 °C for 30 min. The method applied here to detect anticomplement activity was described earlier by Price et al [3], In short, sheep red blood cells (SRBC) were washed 3 times. The final concentration of SRBC was modulated to 4 x 108 cells/ml.…”