Cholinergic mechanisms in the rat detrusor muscle.

The motor response of the urinary bladder to nerve stimulation is resistant to atropine, and it has been proposed that the nerves are non-cholinergic, but are possibly purinergic. In this review evidence is presented suggesting a cholinergic transmission in the rat detrusor muscle, part of the receptors being inaccessible to atropine. The rat bladder receives postganglionic cholinergic fibres not only from the pelvic but also from the hypogastric nerves, some fibres passing outside the pelvic ganglia and some relaying distal to them. There is a functional overlap between the right and the left pelvic nerve, but the contractile response to stimulation of the hypogastric nerves is added to the pelvic nerve response with no functional overlap or antagonism.