Local uterine regulation of the corpus luteum

Abstract

In order to determine if the well known uterine inhibition of the guinea pig corpus luteum is a local effect, a series of partial hysterectomies were performed. Some groups were subjected to one-half or three-fourths hysterectomies alone, while in others one ovary was also removed on either the side retaining some or the side losing all uterine tissue. In addition, two groups in which all ovarian and uterine tissue was preserved were subjected to unilateral or bilateral complete surgical separation of all communicating structures between uterus and ovary. Sham-operated, totally hysterectomized, and unilaterally ovariectomized groups were used as controls.In all groups in which an ovary left in the animal was separated from direct contact with its uterine horn, the estrous cycles became long and erratic, or were arrested completely due to the persistance of active corpora lutea in those ovaries. However, corpora lutea regressed normally in all ovaries left in their normal relationship to a uterine horn. These results indicate that the uterine regulatory factor does reach the ovary by some local route.The mammalian uterus has, since ancient times, been known as the organ in which the young undergo embryonic development, yet only within the last 45 years has it been suspected of playing a more subtle role in the physiology of reproduction. Experiments conducted by Loeb (' 23, '27) upon the guinea pig demonstrated that, in at least this one form, the uterus is capable of contributing to the regular cyclic rhythmicity of the ovary by periodically curtailing the functional life of the corpus luteum. Loeb found that removal of the uterus a few days after estrus resulted in a sudden and complete cessation of all cyclic activity for a period much longer than the normal duration of pregnancy. The corpora lutea in these anestrous animals were evidently in a state of high activity; they were larger than those of pregnancy, and were composed of large polygonal cells, many of which were in mitosis.Histological examination of the vagina and mammary glands gave additional evidence that the corpora lutea were actively secreting progesterone. Since Loeb's work, this phenomenon in the guinea pig has been amply confirmed by many others, and has been proven to exist in other mammals. In all cases where hysterectomy provokes a disruption of the sexual cycle, the corpus luteum is maintained in an apparently functional state. AM. J. ANAT., 121: 425-442.Loeb's experiments quickly stimulated interest in the field of utero-ovarian relationships. Studies were made of many different mammals to determine whether the effect of hysterectomy was of a more general occurrence. In recent years, it has also been found that distension of the uterus results in the opposite phenomenon, the early regression of corpora lutea and concomitant shortening of the estrous cycle (Moore and Nalbandov, '53). The results of the various types of experiments performed during these years fall into three main groups. No apparent uterine influence onthe ovary ...

Uterine distension and the function of the corpora lutea in the guinea‐pig

“…This conclusion is in accord with the findings of experiments involving removal of the uterus and the introduction of endometrial extracts or transplants (see Bland & Donovan, 1966a) and with those experiments revealing that partial hysterectomy in the sow and guinea-pig respectively may extend luteal function in the ovary on the operated side while not affecting the contralateral ovary (Du Mesnil du Buisson, 1961;Fischer, 1965). In the guinea-pig, Fischer (1965) noted that after hemi-hysterectomy the corpora lutea were maintained for extended periods in the ovary deprived of uterine influence. The volume of the corpora lutea in hemihysterectomized guinea-pigs has been measured by Bland & Donovan (1966b), who found that the corpora lutea in the ovary adjacent to the intact horn regressed normally while those in the ovary on the operated side enlarged.…”

Mechanism of prostaglandin F-2 penetration from the horn of the uterus to the ovaries in pigs

“…The time of survival of corpora lutea in the ipsilateral ovary is controlled by the uterine horn in sheep (Inskeep & Butcher, 1966; Thorburn & Nicol, 1971;McCracken et al, 1972), guinea-pigs (Bland & Donovan, 1966;Fischer, 1967) and cows (Ginther, Woody, Mahajan, Janakiraman & Casida, 1966). In pigs, however bilateral regression occurs after semihysterectomy (Spies, Zimmerman, Self & Casida, 1958), although if as little as one-quarter of one horn is left intact, the corpora lutea on the opposite side do not regress (du Mesnil du Buisson, 1961).…”

Observations on the Time of Action and the Pathway of the Uterine Luteolytic Effect of the Guinea-Pig

“…Experiments with partial hysterectomy have shown that this luteolytic action acts on a local basis such that each uterine horn influences only its neighbouring ovary (Fischer, 1965(Fischer, , 1967Bland & Donovan, 1966a; Barley, Butcher & Inskeep, 1966). Experiments with unilateral uterine distension have sub¬ stantiated this fact (Bland & Donovan, 1965, 19666;Ginther, Mahajan & Casida, 1966a, 19666).…”