Properties of Ca2+-activated K+ channels in erythrocytes from patients with myotonic muscular dystrophy
✍ Scribed by Mario Pellegrino; Monica Pellegrini; Paolo Bigini; Annalisa Scimemi
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 197 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0148-639X
No coin nor oath required. For personal study only.
✦ Synopsis
Using the single-channel patch-clamp technique, Ca 2+activated K + channels of erythrocytes from patients with myotonic muscular dystrophy (MyD) were studied. Elementary single-channel propertiesconductance, rectification, kinetics, voltage-and calcium-dependencemeasured in inside-out patches of MyD erythrocytes, did not differ significantly from those of control cells. The activity of the channels, studied in patches attached to red cells from MyD patients, exhibited mean patch currents which were significantly higher than the controls. The increased mean patch current was due to a higher opening frequency, associated with a reduced mean channel closed time. These results indicate that Ca 2+activated K + channels of erythrocytes from patients either detect a higher intracellular calcium concentration and/or express an augmented calciumsensitivity. Since these channels are targets for phosphorylation, our findings make it possible to identify defective kinase mechanisms, in minimally disturbed cells of the patient, at a molecular level of resolution.