Agonist-induced contractile responses of human bronchial muscle in vitro: Effects of Ca2+ removal, La3+ and PY108068

The effects of reducing the extracellular Ca2+ concentration ([Ca2+]0), the effects of La3+ and the dihydropyridine Ca2+ entry blocker PY108068 on contractile responses in human isolated bronchial strips have been compared. Reducing [Ca2+]0 or the presence of La3+ (1 mM) caused a reduction in basal tone, whereas PY108068 (1 microM) had no effect on unstimulated preparations. Response to KCl and A23187 were, in general, more markedly depressed …