Multiple forms of synaptic coordinative interactions in the autonomic neurotransmission. Tensiometric evaluations in peripheral tissues.

The existence of co-transmitters interacting in the complex regulation of autonomic neurotransmission, has led to investigate the interactive effects between the conventional neurotransmitters and other drugs, such as histamine, serotonin, substance P, strictly related to inflammatory mediators, in both vas deferens and urinary bladder of guinea pig. The results suggest that synergistic interactions, involving post-synaptic sites, exist between co-transmitters; furthermore, inflammatory mediators are able to modify the responses to endogenous (via intramural nerves stimulation) and exogenous conventional neurotransmitters. It is conceivable that inflammatory mediators, released by activation of mast cells either within or delivered to the tissues by the vascular supply, may alter the physiological responses of several organ systems.