Electrophysiological effects of erythromycin, but lack of mechanical effects, in airway smooth muscle.
The antibiotic erythromycin has been shown to modulate a variety of electrophysiological and mechanical responses in many cell types. We investigated whether it did so in airway smooth muscle using standard patch clamp, fura-2 fluorimetric and organ bath techniques. Erythromycin (10(-4) M) evoked a small transient inward current with reversal potential and time-course similar to that of the Ca2+-dependent Cl- currents seen in these cells. Unlike its effects in other cell types, however, it did not alter basal [Ca2+]i, voltage-dependent Ca2+ currents, nor mechanical tone at rest, nor the corresponding responses to cholinergic stimulation (membrane currents; release of internally sequestered Ca2+, nor contractions evoked by neural stimulation or exogenously added cholinergic agonist). In conclusion, erythromycin does exert interesting electrophysiological actions in airway smooth muscle, but does not alter mechanical activity as it has been shown to do elsewhere.
Janssen
Luke J
LJ
Asthma Research Group, Firestone Institute for Respiratory Health, St. Joseph's Hospital, Hamilton, Ontario, Canada L8N 3Z5. janssenl@mcmaster.ca
Wattie
Jennifer
J
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D004917:Erythromycin / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D014132:Trachea / Q000187:drug effects / Q000502:physiology*
D004917:Erythromycin