Beta-adrenergic stimulation does not influence the activity of lymphocyte Kv1.3 channels

The aim of our study was to clarify the still controversial problem concerning the modulatory effect of β-adrenergic stimulation on the activity of Kv1.3 channels in human T Lymphocytes. Because the expression of β-adrenergic receptors in T Lymphocytes is significantly altered in patients with bronchial asthma we examined the cells taken both from healthy donors and asthmatic patients. We applied the whole-cell patch-clamp technique to study the modulatory effect of β-adrenergic stimulation on the whole-cell potassium conductance, gating and kinetics of Lymphocyte Kv1.3 channels. During the experiments β-adrenergic agonist Isoprenaline was applied at concentrations up to 10-4 M. It was shown that the activity of T lymphocyte Kv1.3 channels remain unchanged upon β-adrenergic stimulation both in cells taken healthy donors and asthmatic patients. Results of our investigations support the notion that β- adrenergic stimulation does not modulate the activity of Kv1.3 channels in human TL. The transient increase in T lymphocyte K+ channel activity upon β-adrenergic stimulation that has been reported in some previous studies is most probably due to an activation of recently identified, voltage-independent cAMP-responsive K+ channels.