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A Superfusion System Technique for the Study of the Sites of Action of Glucocorticoids in the Rat Hypothalamus- Pituitary-Adrenal System<i>in Vitro</i>. II. Hypothalamus-Pituitary Cell-Adrenal Cell Superfusion
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References
1977
Year
Superfused Hypothalamus TissueAdrenal GlandPituitary GlandStress HormoneNeurophysiologyHypothalamusSuperfusion System TechniquePhysiologyMedicineLog Dose-response CurvesNeuroendocrine MechanismNeuroendocrine DisorderNeuropharmacologyCrf ReleaseGlucocorticoidNervous SystemEndocrinologyPharmacology
Basal and stimulated CRF release by hypothalamic blocks was studied by coupling the effluent of superfused hypothalamus tissue to a joint pituitary cell-adrenal cell superfusion system and measuring corticosterone production. Log dose-response curves of the adrenal cells for ACTH and of the pituitary cell-adrenal cell system for CRF were linear over the ranges used. Ca++-independent basal CRF release by the hypothalamus could be blocked in vitro by 0.2 mug/ml dexamethasone in the medium, or in vivo by treating the hypothalamus donor rats with corticosterone, 1 mg/rat ip 30 min before decapitation. These treatments did not impair CRF release caused by Veratridine (5 x 10(-6)M or by electrical stimulation. Adrenalectomy increased only basal but not stimulated CRF release. These results indicate that glucocorticoids have a hypothalamic site of action.