Variation of lipid composition of pig (Sus scrofa) spermatozoa with pH

RODOLFO CABRERA; MÓNICA HOURCADE; PATRICIA ESTELA MARINI; MARCELO O CABADA

Rosario

Congreso; XLII Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2006

SAIB

Mammalian spermatozoa undergo  changes  on their journey through the female genital tract. The pH also varies along this path. To determine the possible influence of pH over lipid composition of  pig  sperm,  cells were incubated in non capacitating media at pH 6.60 (uterus) and  7.60 (oviduct). Total  lipid extracts  were assayed for the composition of fatty acids involved in the acylglicerides as molar % using GC-FID with an internal standard.  The acyl moieties that showed statistical significant differences  were: C14:0, C22:6 (p<0.005);  C18:1, C22:5 (p<0.01) and C22:4(p<0.0001)(n=15). The amounts of total acyl mass differed significatively (p<0.005, n=15). The profile of sterols (as relative %) and their total amounts were also estimated for samples incubated at both pH, using GC-MS of their trimethylsylyl derivatives, with an internal standard. Cholesterol, desmosterol and a third sterol (probably hydrodesmosterol), not described previously as a component of boar sperm, were  found. A significative statistical difference was found in cholesterol relative % (p<0.05,n=16) when incubated at different pH. Neither desmosterol nor the third sterol showed  significant differences. Sterol’s masses also differed significatively (p<0.05, n=13). The present results indicate  that variations in pH promote changes in  the total lipid composition of boar sperm.