Characterization of polypeptides synthesized and secreted by oviductal epithelial cell explants obtained from young, fertile and aged, subfertile mares

Objective - To compare the electrophoretic patterns of proteins synthesized and secreted by oviductal epithelial cell (OEC) explants obtained from young, fertile and aged, subfertile mares. Animals - Young, fertile (n = 5; 2 to 7 years old) and aged, subfertile (n = 5; 17 to 24 years old) mares. Procedure - 2-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and computerized densitometry. Results - Variation in the synthesis and secretion of polypeptides from young, fertile mare OEC (YOEC) and aged, subfertile mare OEC (AOEC) was evidenced by differences in the intensity of radiolabeled polypeptides on fluorograms. Fluorograms for 9 acidic (isoelectric point, 5.09 to 6.50) proteins of low to medium molecular mass (18.2 to 85.0 kd) from YOEC had greater intensity than did those from AOEC. Fluorograms for 7 proteins (10.5 to 45.0 kd; isoelectric point, 5.80 to 6.92) from AOEC had greater intensity. Conclusion - The differences detected in the fluorographic intensities of secreted proteins from YOEC and AOEC may be related to the disparity in embryo development observed between young, fertile and aged, subfertile mares. Clinical Relevance - Failure to maintain pregnancy in aged, subfertile mares may be a result of a suboptimal oviductal environment exerting its effects on the conceptus during early cleavage.