The Role of the Fertilized Egg: Reactions in the Guinea-Pig Uterus at Ovoimplantation and After Thread Traumatization

Abstract

Unilaterally sterilized guinea-pigs were mated and the sterile uterine horn traumatized 0 to 7 days later by the passage of two or more threads which were left in situ. The animals were killed 3 to 7 days after traumatization and the endometrial reactions studied histologically. Although deciduomata developed in uteri traumatized 4 to 7 days after mating, those traumatized up to 3 days after mating and killed up to 5 days later showed little reaction and contrasted markedly with the corresponding horns in which fertilized eggs were becoming implanted. This difference, not affected by exogenous progesterone treatment, indicates that the fertilized eggs have a specific capacity to induce changes in the endometrium, while it is non-reactive to other stimuli.Traumatization of both uterine horns did not completely inhibit ovoimplantation or subsequent pregnancy.

Reduction in endometrial neutrophils in proximity to implanting rat blastocysts

“…Since increased endometrial microvascular permeability is one of the few features that appears to be common to the implantation reaction seen in most placental mammals (Psychoyos, 1960;Deanesly, 1967;Boshier, 1970;Keys et al, 1986), it is important to know whether neutrophils play a role in species other than mice. The aim of the present study was to quantify the immunohisto¬ chemical distribution of rat endometrial neutrophils over 19 h starting just before any observable increase in microvascular permeability in response to implanting embryos.…”

Normal Growth and Persistence of Corpora Lutea of Both Ovaries in the Unilaterally Pregnant Guinea-Pig

“…Guinea-pigs were from the colony at the Institute. Examination of the animals and operative and histological techniques were the same as in previous work (Deanesly, 1967).…”

The Differentiation of the Decidua at Ovo-Implantation in the Guinea-Pig Contrasted With That of the Traumatic Deciduoma

“…For animals and operations, methods were the same as in earlier work 91 92 R. Deanesly (Deanesly, 1967). The morningof the appearance of a vaginal plug was recorded as Day 0.…”

“…Timing and development of the traumatic deciduoma Earlier work had shown that threads placed in a sterile uterine horn 3 or 4 days after mating caused little or no decidualization of the stroma up to Day 7 (Deanesly, 1967). Additional uteri were examined in the present series with special reference to the early development and spread of deciduomata in uteri traumatized 5 and 6 days after mating, near the time of ovo-implantation.…”

“…Earlier work (Deanesly, 1967) showed that the pregnancy decidua developed very rapidly in the guinea-pig at a time when non-pregnant uteri in the same females, traumatized 3 or 4 days after mating, remained apparently unreactive. The present study has been extended to earlier implantation stages before and after the blastocyst passes through the uterine epithelium.…”