Insulin binding sites induced in the Tetrahymena by rat liver receptor antibody.

Tetrahymena cells treated with purified rabbit antibodies to rat hepatocellular membrane exhibited a considerable increase in binding capacity on reexposure to the antibody 24 h later. Insulin binding was similarly enhanced by preexposure to the antibody, and vice versa, preexposure to insulin enhanced the later binding of rat liver receptor antibodies. This suggests that (1) the Tetrahymena and the rat possess similar insulin receptors, and (2) the receptor antibody is also able to induce imprinting for itself as well as for insulin. Concanavalin-A, noted for binding overlap with insulin, failed to induce imprinting either for insulin or for antibodies to receptors, whereas the latter did induce imprinting for Concanavalin-A.