Fig. 6. Characterization of EFS-induced relaxation.
In order to characterize the chemical nature of inhibitory neurotransmission, bioengineered intrinsically innervated IAS constructs were pre-incubated with inhibitors before stimulation with electrical field. The inhibitors blocked nitric oxide synthesis (L-NAME) or antagonized VIP receptors (VIP-Ra). In the presence of L-NAME or VIP-Ra, the magnitude of EFS-induced relaxation was significantly reduced (P<.05). This implies involvement of both nitrergic and VIP-ergic inhibitory stimulation in response to electrical field. TTX abolished EFS-induced relaxation, indicating that the process was entirely neuronally mediated. Values are mean ± SEM of 3 experiments.