Activador del Plasminógeno Tipo Uroquinasa en Oviducto Porcino: Síntesis y Expresión Génica

EUGENIA M. ROLDÁN OLARTE; MARTIN E. ARGAÑARAZ; PABLO A. VALDECANTOS; DORA C. MICELI

Tafí del Valle, Tucumán

Jornada; XIX Jornadas Científicas de la Sociedad de Biología de Tucumán (ABT); 2002

Asociación de Biología de Tucumán

Plasminogen activators (PAs) are serine proteases that transform plasminogen in plasmin, which can acts on various substrates, modifying the extracellular matrix. This system has been recently involved in several steps of the reproduction process. Previously we have analyzed PA activity in tissue extract of porcine oviducts and have characterized those activities as tPA (tissue type plasminogen activator) and uPA (urokinase type plasminogen activator). During the sexual cycle, there were differences between follicular and luteal phases indicating their hormonal regulation. The aim of this work was to determine by Western blot the presence of uPA activity in oviductal flushing. We found only a band of approximately 54 KDa corresponding to uPA. uPA varies during the estrous cycle, it being more intense in metestrus or early luteal phase than previous ovulation stages. To confirm whether uPA increases was due to oviducal synthesis or it is the product of serum transudation or follicular fluid contamination, we verified uPA gene expression by Northern Blot. A hybridization signal at 2,4 Kb corresponding to uPA mRNA was found. The expression levels normalized with b-actin mRNA confirmed that uPA gene transcription is the biggest after ovulation, indicating that uPA is synthesized and secreted differentially in the oviduct during the sexual cycle. The data obtained in this study suggest that this enzyme could act in the remodeling of the eggs extracellular matrix during their transit through the oviduct or in the maintenance of oviductal lumen fluidity.