The incidence of experimentally produced abdominal implantations in the rat

Spontaneous abdominal implantation in the rat with development to full term

“…sac and genita! tract normally provide a barrier to penetration by rodent embryos, and even when this barrier is artificially breached abdominal implantation is uncommon or abortive after a few days of development (Fawcett, Wislocki & Waldo, 1947;Jollie, 1961;McLaren & Tarkowski, 1963). There is only one documented account to show that implantation in an ectopic site is not a bar to full development in the rat (Nicholas, 1934).…”

Implantation of Mouse Eggs in the Peritoneal Cavity

“…Jollie (1961) could detect no embryonic structures in any of his implantations. Kirby ( 1960Kirby ( ,1962b observed a correlation between the formation of embryonic structures and the stage of eggs used for trans¬ plantation to the kidney : embryonic structures developed sometimes from blasto-cysts, never from earlier stages.…”

“…This type of invasion resembles the interstitial type of uterine implantation found in guinea-pig and man, and differs strikingly from the eccentric type of implanta¬ tion characteristic of the mouse, in which the blastocyst occupies a diverticulum in the wall of the uterus, initially continuous with the main uterine lumen. The usual Jollie, 1961, though not conclusive, suggests that local release of histamine may be involved.) All six implantations in our first series were on the outer surface of the reproductive tract, in regions which might have suffered damage during the course of the transfer operation.…”

“…The incidence of implanted eggs was very low (less than 5 %). The work of Jollie (1961) shows that both methods can lead to intraperitoneal implantation in rats, and suggests that local treatment with histamine may increase the rate of implantation. Even using histamine, however, fewer than 1 % of the eggs implanted in the peritoneal cavity.…”

The Fate of Trophoblast Retained within the Oviduct in the Mouse

“…This scarcity of tubal pregnancies is surprising in view of the fact that under experimental con ditions embryos from mice, rats and guinea pigs readily implant when transferred to a variety of extrauterine sites regardless of the hormonal status of the recipient. Trophoblast has been found to grow extensively in the abdominal cavity, kidney, muscle, spleen, testes and the anterior chamber of the eye [9][10][11][12][13] in both the mouse and the guinea pig.…”