[Mechanisms of release of adrenaline and noradrenaline from the caudal mesenteric ganglion of dogs].

Adrenaline (A) and noradrenaline (N) release from the caudal mesenteric ganglion (CMG) during preganglionic nerve stimulation is due to acetylcholine action on N--and M-cholinoreceptors of ganglion's adrenergic structures (GAS) and probably, primarily on SIF--cells, whereas during peripheral reflexes of CMG it is related to the excitation of noncholinergic afferent neurons which affect the corresponding receptors of GAS. A and N release is inhibited via M-receptors. There is a complex relationship between receptor fields of GAS. Hemicholinium as well as N--cholinoblocking agents, during first minutes of their application to the ganglion elicit A and N release both before and after preganglionic fiber degeneration, which indicates their postsynaptic effect on the cholinoreceptors. Changes in A and N in the ganglion during peripheral reflexes are increased after prolonged action of hemicholinium and chronic decentralisation of CMG.