[Transferrins in rabbit ocular fluids].

A study of transferrins in serum, aqueous humour, and vitreous in the rabbit suggests that the three proteins are immunologically identical. Electrophoretic and enzymatic analyses indicated that the serum and aqueous transferrin, as well as an important part of that of the vitreous, have two residues of sialic acid per molecule. The remainder of the vitreous transferrin contains little or no sialic acid. The transfferin level in the ocular media appears to depend partly on a local synthesis in the posterior segment; this is confirmed by a study of the specific activity of 125-I transferrin after intravenous injection of this labelled protein.