Pituitary colloid--a non vascular secretion with immunoglobulin-like properties.

We show evidence of an internal holocrine secretion capable of distributing its immunoreactive substances to the cerebrospinal fluid (CSF) and to the venous circulation of the cavernous sinuses. The substances, covering a wide molecular weight range, appear on immunoelectrophoresis, to be similar to serum proteins. Double diffusion shows no identity to serum immunoglobulins or albumin even though antisera produced against serum components react positively. Of equal interest is their identification with pituitary hormones, which theoretically are secreted directly into the blood stream. There is a suggestion that elevated or suppressed levels of immunoglobulins and other serum components manifest by current methodology may, in fact, be due to changes in pituitary function. This paper proposes that we take a serious look at the intermediate lobe of the pituitary gland, and examine its unique and individual contributions to our biological chemistry.