"Identification of tPA and uPA in oviductal flushing and soluble membrane fraction of pig oviduct"

ROLDÁN M.; JIMÉNEZ-DÍAZ, M.; PERALTA, L Y MICELI, D. C.

Tafí del Valle, Tucuman, Argentina

Jornada; XVII Jornadas Científicas de la Asociación de Biología de Tucumán; 2000

Asociación de Biología de Tucumán

IDENTIFICATION OF tPA AND uPA IN OVIDUCTAL FLUSHING AND SOLUBLE MEMBRANE FRACTION OF PIG OVIDUCT. M. Roldán, M. Jiménez Díaz, L. Peralta and D. Miceli. Instituto de Biología. Facultad de Bioq., Qca. y Fcia. INSIBIO - UNT, Chacabuco 461, 4000, Tucumán. micelid@unt.edu.ar   It is well known that proteolitic enzymes are involved in several biologic process, including the reproduction. We are studying the participation of plasminogen activators (PAs) in the fertilization. There are two types of PAs, tissue type plasminogen activator (tPA) and urokinase type (uPA). They have been detected in ovary and it was observed that their activities are induced by gonadotrophines. The activity and characterization of PAs in pig oviduct in different stages of the estrous cycle are reported. Determination of PA activities were assayed in oviductal flushing and Soluble Membrane Fractions (SMF), obtained by treatment of tissue crude membrane fraction with Triton X-100 corresponding to ampulla and isthmus regions. We compared the activity of oviducts obtained from immature sows and females in proestus and diestrus, using a chromogenic substrate method (S-2251). In order to inhibit the action of physiological inhibitors, the samples were acidified before the assay. The highest specific activity of SMF was observed during proestrus in the isthmus region. In oviductal flushing we found differences: the specific activity was very low in prepubertal oviductal flushing, while in diestus it was very high. Using amiloride, an specific inhibitor of uPA, we detected that near of 100% of PA activity in all SMF assayed corresponds to tPA. In oviductal flushing we observed that a 41% of activity was due to uPA in diestrus. The changes in the activity of PA in prepubertal, proestrus and diestrus oviducts would indicate that their activities could be regulated by sexual hormones.