1-O-Alkylglycerols Improve Boar Sperm Motility and Fertility

O-Alkylglycerols are naturally occurring ether lipids with potent biological activities. They may interfere with lipidic sig- naling, and they amplify platelet-activating factor (PAF) biosyn- thesis in a monocyte cell line. The PAF is produced by mam- malian sperm and is an important activator of sperm motility. The aim of this study was to evaluate the effect of in vitro treat- ment of boar spermatozoa with natural 1-O-alkylglycerols (10 mM) on 1) boar sperm motility; 2) production of PAF and its metabolite, lyso-PAF, by spermatozoa; and 3) fertility in artificial inseminations of breeding sows. Using a computer-assisted sper- matozoa analyzer, we found that 1-O-alkylglycerols increased percentage motility as well as velocity parameters after 24 h. These effects were partially or totally reversed by the PAF re- ceptor-antagonist SR 27417. After ( 3 H)-1-O-alkylglycerol incu- bation with boar spermatozoa, we identified ( 3 H)lyso-PAF by high-performance liquid chromatography. Production of PAF and lyso-PAF was measured with a biological assay using ( 3 H)serotonin release from rabbit platelets. 1-O-Alkylglycerols significantly increased lyso-PAF production but had no effect on PAF production. The effect of 1-O-alkylglycerols on fertilization was also evaluated in industrial breedings: 1-O-alkylglycerol- treated or untreated semen dilutions were alternately used for artificial inseminations of sows on 12 farms. 1-O-Alkylglycerol treatment increased the number of farrows but had no effect on the mean size of the litters. This study demonstrates that 1-O- alkylglycerol treatment of boar spermatozoa in vitro improves their motility and fertility, and it suggests that this effect is re- lated to PAF metabolism and function in boar spermatozoa. fertilization, signal transduction, sperm motility and transport