Immunoreactive corticotropin-releasing factor in rat plasma.
Immunoreactive ACTH (I-ACTH) levels in the rat anterior pituitary and plasma, and immunoreactive corticotropin-releasing factor (I-CRF) concentrations in the median eminence (ME) and plasma were determined after adrenalectomy and in insulin-induced hypoglycemia. I-CRF was detected in plasma from normal rats (mean +/- SD, 5.6 +/- 0.9 pg/ml; n = 6). Gel filtration chromatography of I-CRF from pooled plasma of these rats revealed a single peak which eluted in the position of authentic rat CRF. I-CRF levels in ME and I-ACTH levels in anterior pituitary decreased immediately after adrenalectomy, then gradually increased to high levels 14 days after surgery. Plasma I-CRF and I-ACTH concentrations increased immediately after surgery, slightly decreased to near the control levels at 24 h, and then increased to high concentrations 14 days after surgery. Plasma and ME I-CRF levels 14 days after adrenalectomy, followed by daily dexamethasone replacement, were almost the same as control levels. In insulin-induced hypoglycemia, plasma I-ACTH and I-CRF concentrations increased and ME I-CRF content decreased at 30 and 60 min. These results suggest that plasma I-CRF levels reflect changes in hypothalamic CRF levels.
D000315:Adrenalectomy; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism; D000818:Animals; D002850:Chromatography, Gel; D003346:Corticotropin-Releasing Hormone / Q000097:blood* / Q000378:metabolism; D007003:Hypoglycemia / Q000139:chemically induced / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D007328:Insulin; D008297:Male; D008473:Median Eminence / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone