Effect of isthmic and ampullary oviductal proteins on lipid peroxidation levels of buffalo spermatozoa

Abstract

A study was undertaken to find out the effect of oviductal proteins from different regions of oviduct and phases of
estrous cycle on lipid peroxidation (LPO) of buffalo spennatozoa. Oviducts were collected from apparently healthy buffalo
genital tracts (nonluteal and luteal phases of estrous cycle) and separated into isthmus and ampulla. Each segment of oviduct
(nonluteal and luteal) was flushed with PBS (pH 7.4), centrifuged, filtered and frozen at -20°C. Proteins in pooled nonluteal
isthmic and ampullary and luteal isthmic and ampullary fluids were precipitated overnight using ammonium sulphate, centrifuged
and dialyzed (> JOkDa). Aliquots of IO mg proteins were lyophilized in cryovials and stored at -20°C. Pooled good
quality ejaculates (n=6) from two Murrah buffalo bulls were utilized for the study. Each pooled ejaculate was split into five
parts, extended in Tris-Egg Yolk-Citrate extender and cryopreserved in 0.5 ml French straws at -I 96°C. Before freezing, the
isthmic and ampullary (luteal and nonluteal) oviductal proteins were supplemented ( I mg per ml). Random semen straws from
each group were evaluated for LPO levels in sperm and seminal plasma in equilibrated and frozen thawed semen. Results
revealed that addition ofnonluteal isthmic oviductal proteins reduced the LPO level in post thaw spermatozoa significantly
(p<0.05) whereas, no significant differences in LPO levels among other proteins added and control groups was seen. Thus, it
was inferred that oviductal proteins differentially affect LPO levels of sperm depending upon the region of oviduct and the
phase of estrous cycle.