Distribution of ACTH-like immunoreactivity in rat brain and gastrointestinal tract.
Immunocytochemistry reveals ACTH-like immunoreactivity to reside not only in the pituitary but also in central nerves and in central nerves and in antral gastrin cells. In all probability, the central nerves store a peptide identical with or closely resembling true ACTH. Their pattern of distribution is, in some regions, similar to that of enkephalin-immunoreactive nerves. The antiserum demonstrating ACTH-like immunoreactivity in central nerves and in antral gastrin cells is directed towards the COOH-terminal part of the hormone. A peptide corresponding to this part, the corticotrophin-like intermediate peptide (CLIP) is manufactured by the pars intermedia of the pituitary. CLIP is devoid of adrenocortical activity, but has recently been shown to possess insulin-releasing activity. The occurrence of CLIP-like peptides in antral gastrin cells may indicate a role for such peptides in the gastrointestinal regulation of insulin release. The simultaneous occurrence of enkephalin-like and ACTH-like immunoreactivity in the antral gastrin cells is of particular interest since a large precursor molecule, containing both the enkephalin and the ACTH sequence has recently been identified.
D000324:Adrenocorticotropic Hormone / Q000276:immunology*; D000818:Animals; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000032:analysis*; D007031:Hypothalamus / Q000032:analysis*; D007124:Immunoenzyme Techniques; D008297:Male; D010902:Pituitary Gland / Q000032:analysis*; D051381:Rats
D000324:Adrenocorticotropic Hormone