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Thesis (M.S.)—University of Nebraska—Lincoln, 1973. Department of Animal Science.


Copyright 1973, the author. Used by permission.


The involvement of the oviduct in regulating ovarian function in the cyclic rat was investigated in two identically designed experiments.The experimental design involved five treatment groups with each group receiving different surgical modifications of the reproductive tract.The surgical modifications included removal of the uterus and both oviducts, both oviducts and the sham operated controls.A third experiment of this study was designed and conducted to qualitatively identify prostaglandins E1 and F in the uterine and oviductal extractions during different stages of the rat estrous cycle.Extractions were made from three different stages (estrus, diestrus, and metestrus) of the estrous cycle.

The results from these studies indicate that the oviduct and the uterus do have an inhibitory action on ovarian function in the cyclic rat, even though their removal does not appear to alter estrous cycle length.It appears that the removal of the oviduct and the uterus allows for an increase in ovarian weight.The increased ovarian weight is probably due to increased follicular development as indicated by increased follicle diameters as opposed to an increase in luteal tissue.The increased follicular activity may be due to an increase in pituitary gonadotropin secretion.Although the exact mechanism of action is unclear the involvement of the pituitary is indicated by the increased plasma LH levels in response to the surgical treatments.The activation of the hypothalamic pituitary region may result from a neural of systemic response from the oviduct and uterus or through a feedback pathway involving the ovary.The exact mechanism(s) by which the oviduct and uterus mediate their apparent inhibitory influence on ovarian activity remains undetermined.

Advisor: Earl F. Ellington