ABSTRACT
This chapter considers the role of the non-adrenergic non-cholinergic transmitters of autonomic nerves. They are generally co-transmitters, which by definition are two or more transmitters released from the same neurone by the invading action potential and which influence the activity of an effector cell, being the target cell or the neurone itself. The main types of co-transmitters of the autonomic nerves are peptides, purines and nitric oxide, and the locations and pharmacology. Neuropeptides are synthesized only in the cell bodies of autonomic neurones, unlike the conventional transmitters or adenosine-triphosphate, which are synthesized at the nerve terminal in the cytoplasm and within the storage vesicle. The neuropeptides are initially synthesized in the Golgi apparatus, as large precursor molecules which may consist of 100 amino acid residues. Neuropeptide Y is a 36-residue peptide with a tyrosine at the N-terminus and a tyrosine amide at the C-terminus.
