Impact of the presence of macrophages in rabbit ejaculates on female fertility

Abstract

The present study was designed to investigate the occurrence of macrophages in rabbit sperm and their impact on female fertility parameters in vivo. Activated macrophages, engaging in sperm phagocytosis (spermiophages), might represent a marker of innate immunosystem activation. Semen samples were collected from rabbit males using an artificial vagina, and spermiophages were identified with fluorescent dye Alexa Fluor 488-AcLDL (Acetylated Low Density Lipoprotein Molecular Probes, USA). For artificial insemination the sperm samples were divided into two groups basing on number of spermiophages: the group R1 - ejaculates with the occurrence of spermiophages less than 20 % of all cells and the group R2 - ejaculates with the occurrence of spermiophages at about 20 - 40 %. The increased occurrence of spermiophages, observed in the R2 group, was associated with decreased female fertility parameters (conceptional rate, liveborn pups). The differences in conceptional rates (73.08 vs. 68.18 %) as well as the differences in average number of liveborn pups per doe between groups of R1 and R2 does were not statistically significant. These preliminary results may indicate the negative impact of higher spermiophage presence in semen on female fertility.