The route by which passive immunity is transmitted from mother to foetus in the rat

Abstract

The route by which maternal γ -globulin reaches the circulation of 19 - and 20-day-old foetal rats has been investigated by surgical experiments on the foetuses in situ and by the use of antibodies as marked globulin. Antibodies from immune rat serum injected into the uterine lumen entered the exocoelomic and amniotic fluids of the foetus by way of the yolk-sac splanchnopleur and amnion. Antibodies from immune rat serum administered by mouth to the foetus were absorbed rapidly in the gut and appeared in the circulation. Antibodies also were absorbed by, and entered into the circulation of, the inverted yolk-sac splanchnopleur from immune rat serum to which it was exposed. They still reached the foetal circulation when entry by both these routes was precluded by keeping the mouth closed and removing the yolk-sac splanch­ nopleur. In these circumstances antibodies probably were absorbed from the cavities in the entodermal sinuses of Duval and must have been transported by the allantoic circulation, but the possibility of passage from the maternal circulation directly across the placenta could not be excluded.

Anaphylactic Antibody in the Young Rat

“…Eight days after immunization of the mothers, the suckling babies showed significant quantities of antibodies in their sera, the ratio of ana phylactic to total precipitating antibody being similar in babies and mothers. These findings are in agreement with other observations concerning the transmission of immunoglobulins from mother to suckling babies in the rat (12), and indicate that both IgG and ana phylactic antibody pass to the milk, and thereafter get across the intestine of the young animal, in approximately the same way.…”

An interspecies comparison of placental antibody transfer: New insights into developmental toxicity testing of monoclonal antibodies

“…This finding indicates the rapid absorption of antibody by the fetal rat gut (Brambell and Halliday, 1956), which is probably mediated by FcRn receptors as in human (Israel et al, 1993). In summary, two main routes for antibody transfer into the fetus circulation from uterine lumen are identified for rodents:…”

Development of Negative Feedback Control of the Hypothalamo-Pituitary-Gonadal Axis in the Male Rat Fetus

“…Even though in rats, when compared to rabbits, immunoglobulins are less readily transmitted from the mother to the fetus [3,4] our results show that rabbit antibodies against testosterone injected into pregnant rats do pass the fetal membranes. The anti body titers achieved through passive immu nization in our rat fetuses were low compared to those of rabbit fetuses after active immu nization of the mother [1], Yet, the testoster one-binding capacity of fetal rat sera reached 20 to 40 ng/ml and thus was high enough to bind and inactivate 10 to 20 times the nor mal plasma testosterone of male rat fetuses.…”

“…The anti body titers achieved through passive immu nization in our rat fetuses were low compared to those of rabbit fetuses after active immu nization of the mother [1], Yet, the testoster one-binding capacity of fetal rat sera reached 20 to 40 ng/ml and thus was high enough to bind and inactivate 10 to 20 times the nor mal plasma testosterone of male rat fetuses. The postnatal rise of the antibody titers which we observed in the young can be ex plained by the high immunoglobulin uptake of the neonate rat from the maternal colos trum [3].…”