Calcitonin gene-related peptide potentiates nicotinic acetylcholinereceptor-operated slow Ca~2+ mobilization at mouse muscleendplates

摘要

The involvement of calcitonin gene-related peptide(CGRP) in the non-contractile slow Ca~2+mobilization induced by prolonged nicotinic stimulation was investigated by measurement of [Ca~2+]Ilevels in mouse single muscle cell(flexor digitorum brevis; FD B) loaded with a Ca~2+ indicator fluo-3using confocal laser scanning microscopy.CGRP(3-30 nM) potentiated acetylcholine(ACh, 1μM)-elicited slow Ca~2+ mobilization in aConcentration-dependent manner.The potentiation by CGRP of the slow Ca~2+ component w as greatly depressed by a competitiveNicotinic antagonist (+)-tubocurarine(5μM). The Ca~2+ channel blocker nitrendipine (1 μM) affected Neither ACh responses nor the CGRP potentiation.