ACTH in bovine pituitary intraglandular colloid, the holocrine secretion of intermediate lobe cells.

The presence of bovine pituitary intermediate lobe peptides in intraglandular colloid, the holocrine secretion of intermediate lobe cells, is explored by ELISA. Intraglandular colloid collected immediately after sacrificing the animal, is placed in phosphate buffered saline, pH 7.6. This material is homogenized, centrifuged to remove extraneous tissue, lyophilized and stored at -20 degrees C. ACTH in intraglandular colloid is measured by competitive ELISA. Human ACTH (1-24) is used in the preparation of the solid phase antigen and as the standard for competition. The antibody is rabbit anti-human ACTH (1-24), and the alkaline phosphatase conjugate is goat anti-rabbit IgG with p-nitrophenyl phosphate as substrate. It is concluded that ACTH is present in bovine pituitary intraglandular colloid of intermediate lobe origin and that the colloid may serve as a transport medium for intermediate lobe materials.