Catecholamines within the rabbit oviduct at fertilization time

Abstract

Dopamine, norepinephrine and epinephrine levels of rabbit oviductal fluids were measured in order to establish whether the ampullary segment contained higher concentrations correlating with the sperm hyperactivity observed in the ampulla of different mammals. In this study, we found no statistically significant differences between flushings from the ampulla or the isthmus at oestrus, ovulation or 72 h post-coitum (p.c.). However, after correcting for the volume secreted, the concentrations of catecholamines are always lower in the ampulla than in the isthmus. In all cases the levels of biogenic amines were highest at oestrus then fell at ovulation. Individual variation of these levels at the time of ovulation was observed only in the ampulla, probably due to some contribution from follicular fluid. During the early luteal phase (72 h p.c.) the catecholamine levels again increase slightly, especially in the isthmus. We conclude that whiplash motility cannot be explained by a higher level of catecholamines in the ampulla.