Objective To explore the regulation of stretch load on the interstitial cells of Cajal (ICCs

pacemaker cells) in guinea pig bladder. Methods Cells were isolated by collagenase digestion and were cultured in special stretch plate. [Ca

2+

]

variation was assessed on Fluo-4 NW dye loaded cells undergoing stretch load or ease state using confocal laser scanning microscopy. Results c-kit positive ICCs were identified with lateral branches in both cultured plate and whole mounted bladder samples. After 4-5 days’ culture

cells were loaded with fluo-4 NW dye. Intermit calcium waves were found in ICCs. The mean fluorescence intensity of calcium waves in ICCs was higher than that in the smo

oth muscle cells (P0.05). The [Ca

2+

]

in ICCs was significantly increased after stretch load and this change was initiated earlier than that in smooth muscle cells. Conclusion Cultured ICCs have periodical calcium wave

and facilitate calcium signals in response to stretch load.