On the subcellular localization of corticotropin-releasing factor (CRF) in the rat median eminence.

Publisher Summary The corticotropin-releasing factor (CRF) is a peptide, possibly related to the neurohypophysial hormone vasopressin. Vasopressin is also present in the hypothalamus, and, although it is found in relatively small amounts, it has been attributed a specific role in the regulation of adrenocorticotropic hormone (ACTH) secretion. A number of different releasing factors have been extracted from the median eminence (ME) region of the hypothalamus and have been partially purified. However, CRF-containing nerve endings, with respect to their sedimentation characteristics, constitute a very heterogeneous population that cannot be easily concentrated by conventional centrifugation techniques. In general, this situation is not uncommon in subcellular localization studies of brain tissue. This is connected with the morphological and functional complexity of this tissue. However, the localization of both substances in different nerve endings indicates that production, transport, and release of CRF and vasopressin take place in separate neurons within the hypothalamus.