Objective  To explore the expression of neuron specific enolase (NSE) and neuronal nitric oxide synthase (nNOS) in the interstitial cells of Cajal (ICCs) in vitro from guinea pigs.   Methods  The ICCs of bladder were primary cultured from guinea pigs by collagenase digestion. The control group was smooth muscle cell (SMC) of bladder primary cultured from guinea pigs. The expression of c-kit and smooth muscle actin (SMA) were detected by immumofluorescence. RT-PCR and Western blotting were used to detect the mRNA level and protein content of NSE and nNOS at 1

3 and 5 d after primary culture.   Results  The expression of c-kit was positive in the ICCs of bladder but negative in the control group

while the expression of SMA was negative in the ICCs of bladder but positive in the control group. Both NSE and nNOS of the ICCs of bladder were high in the mRNA and protein content

but were negative in the control group.   Conclusion  NSE and nNOS were expressed stably in the ICCs of bladder in vitro

indicating that the ICCs of bladder may be involved in the regulation of bladder function.