Pharmacological studies to examine the source of ATP released by pelvic nerve stimulation in the feline lower urinary tract.

1. Pretreatment with 6-OHDA or bilateral sectioning of the hypogastric nerves decreased the noradrenaline content of lower urinary tract tissue. 2. Pelvic nerve stimulation-induced contractions were not significantly changed by either 6-OHDA pretreatment or bilateral sectioning of the hypogastric nerves. 3. Hypogastric nerve stimulation-induced contractions were significantly attenuated by the pretreatments. 4. Neither ATP- nor acetylcholine-induced contractions were significantly altered by either 6-OHDA or bilateral sectioning of the hypogastric nerves. 5. The data indicate that ATP, released by pelvic nerve stimulation, which induces a bladder contraction, is released from parasympathetic, cholinergic nerve fibres in the pelvic nerve trunks and not sympathetic, nor adrenergic nerve fibres also present in the pelvic nerve trunks.