Effects of Prostaglandins on Oviductal Motility and Egg Transport

Abstract

The effects of prostaglandins (PGs) on muscular activity of the oviductal isthmus and on the rate of tubal egg transport are reviewed. In consideration of the available data a mechanism by which PGs contribute to the physiological control of egg transport is suggested. Invivo experiments have demonstrated that E-series PGs relax while F-series PGs stimulate muscular activity of the oviduct in humans, subhuman primates and rabbits. These effects are mutually antagonistic. The response of oviductal muscle to PGs appears to be affected by ovarian steroids; progesterone increases the response to PGE₁ and decreases the response to PGF₂Α. Oviductal tissue concentrations of PGF increase in a distal to proximal sequence following ovulation-induction in the rabbit. Also, proximal isthmus binding of PGE₁ tended to be greater in 72-hour pregnant rabbits than in estrous rabbits, while binding of PGF₂Α was greater in estrous than in 72-hour pregnant animals. It is suggested that the preovulatory increase in ovarian estradiol secretion stimulates PGF synthesis in the oviductal tissue in a sequential fashion, the peak value occurring when the oviductal isthmus is most sensitive to stimulation by PGF₂Α. The changes in tissue concentration of PGF and in sensitivity to PGF₂Α could contribute to occlusion of the isthmus and prevent premature passage of eggs into the uterus. An increase in ovarian progesterone secretion after ovulation may decrease tissue PGF, decrease the response to PGF₂Α stimulation, and increase the response to PGE₁. These changes may then allow a progressive movement of eggs through the isthmus into the uterus. Several questions regarding this proposed mechanism remain unanswered.

Oviduct: roles in fertilization and early embryo development

“…The smooth muscle contraction in the oviduct is regulated by prostaglandins (PGs) through prostanoid receptors, which are modulated by E 2 (Spilman & Harper 1975, Ball et al 2013, Huang et al 2015. In humans, the oviductal PGs are mainly PGE and PGF produced by epithelial cells (Lindblom et al 1983).…”

Responses of the monkey oviduct to transmural electrical stimulation and to drugs

“…By contrast, the responses of the human oviduct in vitro appear to be markedly dependent on hormonal status ; in the Iuteal phase, transmural electrical stimulation and noradrenaline are inhibitory, whereas respon¬ ses are more variable in the follicular phase (Molnar, Johns, Paton, Daniel & Beck, 1976;Moawad, Hedqvist & Kim, 1976). Similarly, the effects of prostaglandins on the monkey oviduct appear to be much less marked than those reported in studies on rabbit and human oviducts (Spilman & Harper, 1975 (Pauerstein, Hodgson, Fremming & Martin, 1974) and on the fertility of female mice (Johns, Chlumecky, Cottle & Paton, 1975), providing more direct evidence against a major role for adrenergic innervation of the oviduct in these species.…”

In vitro regulation of local secretion and contraction of the bovine oviduct: stimulation by luteinizing hormone, endothelin-1 and prostaglandins, and inhibition by oxytocin

“…PGs are reported to modulate oviduct contraction, through effects of E-series PG on relaxation of smooth muscle and of F-series PG on contraction (Spilman & Harper 1975). Human oviduct musculature responds to PGF 2 by increasing tonus (Atanackovic et al 1983), and PGF 2 is recognized as a prerequisite for maintenance of normal tubal contractions (Lindblom & Andersson 1985).…”