Secretory Mechanisms in Opiocortin Cells during Cold Stress.
Abstract
The goals of the study were to characterize the sequence of events involved in the hypothalamic-pituitary responses to cold stress. In the hypothalamus, studies focused on Arginine vasopressin neurons and changes in expression of mRNA following cold and novel environment exposure. In the pituitary, studies focused on AVP and CRH target cells, including corticotropes, thyrotropes, and intermediate lobe cells. Changes in size, granulation, expression of mRNA, and binding sites for AVP and CRH were detected. In vitro studies of second messenger effects or. CRH and AVP binding provided more clues about mechanisms of action. Finally, a new cell type that changed to a multihormonal corticothyrotrope under the influence of AVP was described. It could provide an efficient means of stimulating both the thyroid and the adrenal. Studies implicating locally produced epidermal growth factor (EGF) as another modulatory agent in the stress response were also done because EGF stimulates corticotropes. Cells producing EGF increased expression of EGF mRNA after exposure to cold. In summary, these studies identified four critical hormones that interact with each other in the control of pituitary responses to cold. These included: AVP CRH, throtropin in releasing hormone (TRH) and epidermal growth factor. corticotropes, thyrotropes, cold stress, anterior pituitary, paraventricular nucleus , arginine vasopressin, adrenocorticotropin, Corticotropin releasing hormone, in situ hybridization, immunocytochemistry, image analysis, RIA, rats.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1992
- Accession Number
- ADA252317
Entities
People
- Gwen V. Childs
Organizations
- University of Texas Medical Branch