DIFFERENTIAL-EFFECTS OF GLUCOCORTICOIDS ON CORTICOTROPIN-RELEASING FACTOR IN THE RAT PITUITARY NEUROINTERMEDIATE LOBE AND MEDIAN-EMINENCE

We have investigated the effects of glucocorticoid manipulation on corticotrophin‐releasing factor (CRF‐41) in the neurointermediate lobe (NIL) and median eminence (ME) of the rat using a radioimmunoassay specific for CRF‐41. CRF‐41 content in the NIL (88 ± 7 fmol, mean ± SEM) was not significantly altered by administration of dexamethasone in drinking water for 12 days (67 ± 9 fmol) or adrenalectomy for 12 days (96 ± 17 fmol). The saline‐stimulated increase in NIL CRF‐41 content (154 ± 24 fmol) was not affected by dexamethasone (152 ± 24 fmol) or adrenalectomy (179 ± 21 fmol). In contrast, the content of CRF‐41 in the ME declined following dexamethasone treatment (1247 ± 92 fmol to 864 ± 26 fmol), or adrenalectomy (854 ± 78 fmol). Our results provide further evidence that CRF‐41 in the NIL and ME can be differentially regulated. Copyright © 1990, Wiley Blackwell. All rights reserved