Characterization of the Small ACTH Activity of the Neurointermediate Lobe of the Porcine Pituitary

Summary

The small ACTH activity of the neurointermediate lobe of the porcine pituitary is authentic ACTH (1-39). Porcine neurointermediate lobes were extracted in glacial acetic acid containing 0.1% concentrated HCI, 10 mg% dithiothreitol and 112 mg% 2-mercaptoethanol. After a primary separation by chromatography on Sephadex G-50 (Fine) in 1% acetic acid, a hormonally active material co-chromatographing with ACTH (1-39) was further fractionated and analyzed by several physical methods. By each of these methods, a major region of ACTH activity was located which was indistinguishable from an ACTH (1-39) standard run under the same conditions. Thus, a significant proportion of the ACTH biological and immunological activity in porcine neurointermediate lobe is due to authentic ACTH (1-39). Since the adrenal cortex cannot be maintained by the presence of the neurointermediate lobe alone, the functional significance of the ACTH present is obscure.

Key-Words:

ACTH - Neurointermediate Lobe - Characterization - Porcine Pituitary