Evaluation of in vitro GnRH effects on spontaneous contractions of the bovine myometrium

摘要

Uterine smooth muscle contractile activity in mammals during the follicular phase plays a fundamental role in reproduction. In fact, transport of sperm and uterine clearance are aided by myometrial contractions (Suarez and Pacey 2006). Uterine mechanical functionality is dependent on relative concentration of oestrogens and progesterone. With regard to bovine species, studies on spontaneous contractility have been performed in vivo and in vitro. These have documented strong contractile activity in cattle during the follicular phase and weak and localised contractions during the luteal phase (Hawk 1987). GnRH plays a key role in the regulation of mammalian reproduction. After binding to its heptahelical G protein-coupled receptor on pituitary gonadotropes, GnRH stimulates the biosynthesis and secretion of LH and FSH which regulate gonadal steroidogenesis and gametogenesis.