Renal pelvis and main bronchi hardly possess autonomic efferent nerves, but are supplied by sensory nerves. Thus, electrical „field” stimulation of their nerves elicits mechanical responses via releasing sensory neurotransmitters. Our aim is to influence the release of sensory transmitters with known and putative neuromodulators. Smooth muscle activity of the substances tested can be excluded in preparations possessing spontaneous myogenic activity. Wherever it has not been fully clarified, we intend to identify the sensory transmitters themselves. For this, we shall use specific antagonists. Influencing sensory neurotransmitters may have relevance as to modulating pain and hyperalgesia.