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Immuno-reactive and bioactive corticotropin-releasing factor in rat thymus
1Department of Psychiatry, University of Pennsylvania, Philadelphia 19104-6141.
Insights
Researchers found authentic corticotropin-releasing factor (CRF) in rat thymus tissue. This thymus-derived CRF is biologically active, suggesting a role in neuroendocrine-immune regulation.
Area of Science:
- Neuroendocrinology
- Immunology
- Physiology
Background:
- The neuroendocrine-immune system integrates responses to environmental stimuli.
- Corticotropin-releasing factor (CRF) is a key regulator in the stress response.
Purpose of the Study:
- To identify and characterize corticotropin-releasing factor (CRF) in rat thymus.
- To determine the biological activity of thymus-derived CRF.
Main Methods:
- Radioimmunoassay was used to detect and quantify immunoreactive CRF in rat thymic extract.
- Sephadex G-25 column chromatography was employed for purification and identification.
- Biological activity was assessed by measuring adrenocorticotropic hormone (ACTH) secretion from rat anterior pituitary cells.
Main Results:
- Immunoreactive CRF was detected and quantified in rat thymic extract.
- Thymic extract showed parallel dilution curves with hypothalamic extract and synthetic CRF.
- CRF from thymus co-eluted with synthetic CRF on Sephadex G-25 chromatography.
- Thymus-derived CRF stimulated ACTH secretion in vitro.
Conclusions:
- Authentic CRF is present in rat thymus.
- Thymus-derived CRF is biologically active.
- These findings support the concept of integrated neuroendocrine-immune regulation.
Abstract:
Immunoreactive corticotropin-releasing factor (CRF) was identified and measured by radioimmunossay in rat thymic extract. Serial dilutions of thymic extract paralleled hypothalamic extract and synthetic CRF standard curves. CRF extracted from rat thymus eluted in the position of synthetic rat CRF on Sephadex G-25 column. Thymus-derived CRF was biologically active as demonstrated by stimulating adrenocorticotropic hormone secretion in dispersed rat anterior pituitary cells. These findings indicate the presence of authentic CRF in rat thymus, further supporting the concept of an integrated regulation of the neuroendocrine-immune responses to environmental stimuli.
