Purinergic cotransmission: parasympathetic and enteric nerves

The urinary bladder and the small intestine are presented as the principal models of purinergic cotransmission in the parasympathetic and enteric nervous systems, drawing upon evidence provided by functional, histochemical and ultrastructural studies. In the parasympathetic division ATP probably commonly transmits alongside acetylcholine, and in enteric nerves it is more likely to be transmitting alongside nitric oxide and VIP. Other organs, including some blood vessels and exocrine glands, in which there are hints that ATP might be involved as a parasympathetic cotransmitter are also given consideration.