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 synthesi zed 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-polyacryla mide gel electrophoresis and computerized densitometry. Results-Variat ion 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 fluorogr ams. Fluorograms for 9 acidic (isoelectric point, 5.09 to 6.50) protei ns of low to medium molecular mass (18.2 to 85.0 kd) from YOEC had gre ater intensity than did those from AOEC. Fluorograms for 7 proteins (1 0.5 to 45.0 kd; isoelectric point, 5.80 to 6.92) from AOEC had greater intensity. Conclusion-The differences detected in the fluorographic i ntensities of secreted proteins from YOEC and AOEC may be related to t he disparity in embryo development observed between young, fertile and aged, subfertile mares. Clinical Relevance-Failure to maintain pregna ncy in aged, subfertile mares may be a result of a suboptimal oviducta l environment exerting its effects on the conceptus during early cleav age.