Lack of Correlation Between Immunoreactive Corticotropin‐Releasing Factor Concentration Profiles in Hypophysial‐Portal and Peripheral Plasma

摘要: Corticotropin-releasing factor (CRF-41) is the primary mediator of adrenocorticotropin secretion from adenohypophysis. This 41amino-acid peptide synthesized in perikarya paraventricular nuclei, transported to nerve terminals external zone median eminence and released into hypophysial-portal circulation. It also multiple extrahypothalamic peripheral sites. In addition, immunoreactive (ir) CRF-41 present systemic circulation, raising possibility that measurements might provide a useful index hypothalamic irCRF-41 secretion. hypothesis was tested several rat models. Neither bilateral destruction producing perikarya, nor infundibular stalk transection altered plasma concentration. Furthermore, central administration norepinephrine, an agent previously shown evoke portal without effect on Finally, while increased levels both circulation were associated with nitroprusside-induced hypotension, nuclei lesions blocked blunting rise observed The source remains undetermined; however, adrenals may be excluded as adrenalectomy failed alter circulating levels. Therefore, our observations do not support concept this under conditions tested.