Regulation of bioactive and immunoreactive ACTH secretion by CRF and AVP in sheep fetuses
| Autor: | Jean-Marc Schwartz, Anne White, Timothy J. Zehnder, Nancy K. Valego, James C. Rose |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
endocrine system
medicine.medical_specialty Vasopressin Hydrocortisone Arginine Corticotropin-Releasing Hormone Physiology Endocrinology Diabetes and Metabolism medicine.medical_treatment Radioimmunoassay Blood Pressure Adrenocorticotropic hormone Biology Fetus Adrenocorticotropic Hormone Heart Rate Physiology (medical) Internal medicine medicine Animals Saline Sheep Hydrogen-Ion Concentration Fetal Blood Arginine Vasopressin Endocrinology Hypothalamus Biological Assay Gases Neurosecretion hormones hormone substitutes and hormone antagonists |
| Zdroj: | American Journal of Physiology-Endocrinology and Metabolism. 269:E1076-E1082 |
| ISSN: | 1522-1555 0193-1849 |
| DOI: | 10.1152/ajpendo.1995.269.6.e1076 |
| Popis: | The purpose of this study was to determine the effects of corticotropin-releasing factor (CRF) or arginine vasopressin (AVP) on the secretion of bioactive adrenocorticotropic hormone (bACTH) and immunoreactive ACTH (iACTH), the latter being measured by radioimmunoassay and separate two-site immunoradiometric assays for ACTH-(1-39) and ACTH precursors. Experiments were performed on chronically catheterized fetal sheep at 0.70 (n = 9) and 0.90 (n = 8) gestation. Each fetus received a 15-min infusion of CRF, AVP, or saline on 3 consecutive days. Blood was obtained before and 15 and 60 min after the infusion began. CRF significantly increased iACTH at 15 (younger group) and 60 min (both groups). CRF significantly increased bACTH and the bACTH-to-iACTH ratio (bACTH/iACTH) in both groups at 15 and 60 min. AVP significantly increased iACTH, bACTH, and bACTH/iACTH in both groups at 15 min. In two subgroups (n = 4/subgroup), CRF significantly increased ACTH-(1-39) and ACTH precursors at 15 and 60 min. CRF increased the ratio of ACTH-(1-39) to ACTH precursors [ACTH-(1-39)/ACTH precursors] at 15 (younger group) and 60 min (both groups). AVP increased ACTH-(1-39), ACTH precursors, and ACTH-(1-39)/ACTH precursors in both groups at 15 min. These findings show that both CRF and AVP can stimulate the secretion of bACTH, ACTH-(1-39), and ACTH precursors at 0.70 and 0.90 gestation. The proportional increments in bACTH/iACTH and ACTH-(1-39)/ACTH precursors suggest that CRF and AVP evoke selective increases in bACTH and ACTH-(1-39). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|