Inhibition by steroids of the uptake of potassium by capillaries isolated from rat brain
| Autor: | Richard G. Free, Edward R. Chaplin, Gary W. Goldstein |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Male
medicine.medical_specialty Sodium-Potassium-Exchanging ATPase Potassium medicine.medical_treatment ATPase chemistry.chemical_element In Vitro Techniques Biochemistry Ouabain Steroid chemistry.chemical_compound Corticosterone Internal medicine medicine Animals Pharmacology biology Chemistry Brain Capillaries Rats Endocrinology Lipophilicity biology.protein Steroids Efflux medicine.drug |
| Zdroj: | Biochemical Pharmacology. 30:241-245 |
| ISSN: | 0006-2952 |
| DOI: | 10.1016/0006-2952(81)90084-8 |
| Popis: | The effect of steroids on the uptake and release of K+ by capillaries isolated from rat brain was investigated. 86Rb+ uptake was used as a transport analog of K+. The uptake of 86Rb+ by the capillaries was markedly inhibited by ouabain. The ouabain sensitive fraction of 86Rb+ uptake was inhibited by corticosterone with an I50 of 8 × 10−4 M. Inhibition was immediate in onset and rapidly reversible after removal of the steroid. Corticosterone did not alter the affinity of the transport carrier for K+ or the passive efflux of 86Rb+ from the capillaries. Other steroids inhibited ouabain sensitive 86Rb+ uptake in relation to their lipid solubility. These features suggest a direct membrane action for high dose steroid therapy, possibly on Na+,K+ATPase, rather than a nuclear mediated change in cell function. |
| Databáze: | OpenAIRE |
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