Luteolysis as Affected by Uterine Transplantation in the Syrian Hamster

Abstract

Total hysterectomy in the hamster prolonged corpora luteal life span as measured by the length of copulation-induced pseudopregnancy (18.10 days as opposed to 9.20 days). Reversal of this elongation was accomplished by homologous uterine transplantation to the cheek pouch. Transplantation of estrous rat uteri into the cheek pouch of hysterectomized hamsters significantly shortened the duration of pseudopregnancy. Less conclusive were results obtained from transplanting uteri taken from rabbits on day 14 of pseudopregnancy, although a few cycles were found to be significantly shortened. Transplantation of human endometrium into hysterectomized hamsters was ineffective. Homologous endometrium transplanted into the cheek pouch shortened the length of pseudopregnancy following hysterectomy as effectively as whole uterine transplants. Homologous myometrium did not shorten pseudopregnancy when transplanted alone. The mechanism for control of luteal life span in the hamster appears to involve the uterine endometrium. Proper regulation of ovarian periodicity may depend upon the presence of a threshold amount of uterine tissue which may produce an antiluteal factor. This principle or factor may not be entirely species specific. (Endocrinology 80: 477, 1967) S INCE Loeb (1) first reported the effects of hysterectomy on life span of corpora lutea in guinea pigs, 13 additional mammalian species have been examined in an attempt to clarify the possible regulatory relationship of the uterus on the corpus luteum. In the guinea pig, rat (2), rabbit (3) and hamster (4), luteal life span following hysterectomy is significantly elongated to approximately the normal gestation period for each species. The same operation in the cow (5), sheep (6) and pig (7) usually results in elongation of corpora luteal life span beyond the duration of normal pregnancy. In not all cases are results in agreement, since investigators have reported that some rabbit (8) and rat (9) strains did not show any direct effects of hysterectomy on ovarian function. No change was observed in estrous behavior

Neonatal diethylstilbestrol exposure disrupts female reproductive tract structure/function via both direct and indirect mechanisms in the hamster

“…Prompted by previous reports of the hamster cheek pouch’s utility as an ectopic site for reproductive organ transplantation [29, 57, 58] and by our success using it to study the mechanism of neonatal DES-induced disruption at the uterine level [30, 31], we used it here to further study the mechanism of disruption at the ovarian level. In the original report of ovarian transplantation to the hamster cheek pouch [29], the success rate was ~53 % according to estrous cycle assessments using the characteristic lordosis reflex behavior as evidence of cycle day 1.…”

The Role of the Uterus in Ovarian Control in the Mare

“…Animals in which the presence of the uterus is important for cyclic ovarian activity include the cow (Wiltbank & Casida, 1956), sheep (Wiltbank & Casida, 1956), pig (du Mesnil du Buisson & Dauzier, 1959) and guinea-pig (Loeb, 1923). In the mouse (Bartke, 1970), rat (Bradbury, Brown & Gray, 1950), hamster (Caldwell, Mazer & Wright, 1967) and rabbit (Asdell & Hammond, 1933), hysterectomy does not affect cyclic ovarian function but does result in prolongation of the pseudopregnant state. Recently,344 G. H. Stabenfeldt et al evidence has been presented that hysterectomy prolongs the life span of the CL in the non-pregnant mare (Ginther & First, 1971).…”

Luteotropic and Luteolytic Effects of Prostaglandins in the Hamster

“…While a threshold amount of uterine tissue may be necessary for normal involution of the corpus luteum of pseudopregnancy in the hamster (2), the nature of the uterine factor(s) in this species is not clear. Mazer and Wright ( 3 ) were able to extract an active luteolytic factor with saline.…”