Halothane inhibits hyperpolarization and potassium channels in human red blood cells
| Autor: | Birthe Foder, Ole Scharff |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
4-Acetamido-4'-isothiocyanatostilbene-2
2'-disulfonic Acid Erythrocytes Potassium Channels Protonophore Ionophore chemistry.chemical_element 4 4'-Diisothiocyanostilbene-2 2'-Disulfonic Acid In Vitro Techniques Sodium Chloride Calcium Potassium Chloride Divalent Body Water medicine Humans Calcimycin Pharmacology chemistry.chemical_classification Chemistry Calcium Radioisotopes Hydrogen-Ion Concentration Hyperpolarization (biology) Potassium channel Red blood cell medicine.anatomical_structure Biochemistry Biophysics Halothane medicine.drug |
| Zdroj: | European Journal of Pharmacology. 159:165-173 |
| ISSN: | 0014-2999 |
| Popis: | The effect of halothane on the Ca2+-sensitive K+ channel in human erythrocytes has been investigated. The red cells were suspended in buffer-free salt solutions containing Ca2+ or 45Ca2+. The protonophore CCCP was added to bring about a rapid equilibration of protons across the plasma membrane. After addition of the divalent cation ionophore A23187, the cells took up Ca2+ and this caused the K+ channels to open. When the medium contained 1 mM K+, the addition of A23187 induced a transient hyperpolarization of the cells, as monitored by measurement of the pH of the medium. The cellular pH, being buffered by haemoglobin, was virtually constant. Halothane reversibly inhibited hyperpolarization and limited the release of cellular K+ in a dose-dependent way, but did not inhibit the Ca2+-transporting properties of A23187. No stimulatory effects of halothane were observed even at low halothane concentrations. In conclusion, halothane reversibly inhibits the Ca2+-sensitive K+ channel in human erythrocytes with an ED50 of about 0.5 mM. |
| Databáze: | OpenAIRE |
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