Transplantation of Placental Tissue.

Abstract

Frankl, 1 using mice, showed that “a successful transplantation of a placenta (fetal portion) on a pregnant animal causes persistence of colostrum secretion” beyond the normal period following the birth of the young. Unless the transplants were removed the litters born to engrafted mothers died “evidently from starvation.” Stimson 2 and others report in women with retained placenta, suppression of the secretion of true milk. Our first attempts, without knowledge of these results, were made to obtain living grafts of the fetal or trophoblastic portion of rabbit and rat placentae. In all cases neither gross nor microscopic examination gave evidence of growth after implantation. Since Frankl's results have been used in interpretating the relation of the placental hormones to lactation, and because our experiments, which extended over a period of about a year, have been discontinued, it seems desirable to report our work briefly.

We used trophoblastic tissue (fetal placenta) from rabbits varying in stages of pregnancy from 2 weeks to near full-term, and from rats during mid and later pregnancy. Thin slices of tissue were implanted subcutaneously and intramuscularly, and intraperitoneally in both rats and rabbits. Emulsions of placental cells in Locke's solution were injected into the ear vein of rabbits, and subcutaneously, intramuscularly, and intraperitoneally into both rabbits and rats. Host animals have been, the female from whom the tissues were taken, other females both young and mature, males, and in the case of the rat, also young, about one-fourth grown. Extirpation and implantation in the case of both rabbits and rats was done aseptically under chloral-urethane anesthesia administered by stomach-tube and supplemented by ether. Animals were killed and examined at varying times from 3 days to one month after grafting. Microscopic examinations were made only in cases where gross findings indicated some chance of viability of the graft.