Transmission of human gamma-globulin to rabbit foetus and its inhibition by conjugation with ferritin.

The transmission of a ferritin—human γ-globulin conjugate across the rabbit yolk sac splanchnopleur has been investigated by means of the fluorescent antibody technique, and a comparison made with the transmission of the separate components. Ferritin alone was not transmitted to the foetal circulation and neither was the conjugate, whereas human γ-globulin alone was readily transmitted. However, both the conjugate and the separate components were readily transmitted to the exocoelomic and amniotic fluids by traversing the paraplacental chorion. These results are discussed in the light of a proposed hypothesis to explain selective transfer of proteins.