Purpose: To study the effect of erycibele alkaloid on cultured human ciliary muscle intracellular Ca2+ movement.
Methods: Intracellular Ca2+ was studied by Fura-2 probe and muscarinic antangonist was applied.
Results: Erycibele alkaloid had no any possible disturbulance on the examination system. The average resting[Ca2+]i was 79.3 +/- 28.7 nmol/Lol/L (n = 24). Erycibele alkaloid caused biphase [Ca2+]i elevation. Non-selective muscarinic antagonist Atropine (1 nmol/L) could completely block the 1 mumol/L erycibele alkaloid induced [Ca2+]i elevation; M1 antagonist Pirenzipine could not block the 1 mumol/L erycibele alkaloid induced [Ca2+]i elevation in low concentration (0.03 nmol/L) but in higher concentration (1 nmol/L). M3 antagonist 4-diphenyl acetoxy N-methy piperidine methiodide could completely block the 1 mumol/L erycibele alkaloid induced [Ca2+]i elevation in low and high concentration.
Conclusion: The effect of erycibele alkaloid on increasing cultured human ciliary muscle cell intracellular Ca2+ is mediated by M3 receptor subtype.