Co-release of noradrenaline and ATP from cultured sympathetic neurons

I Von Kügelgen, C Allgaier, A Schobert, K Starke - Neuroscience, 1994 - Elsevier
I Von Kügelgen, C Allgaier, A Schobert, K Starke
Neuroscience, 1994Elsevier
The vesicles of postganglionic sympathetic axons store both noradrenaline and ATP. 22, 31
The theory of noradrenaline-ATP co-transmission implies that both compounds are released
by nerve action potentials and elicit postjunctional effects. Many properties of postjunctional
responses support the theory. 3, 12, 22, 27 However, neural release of ATP has been
difficult to detect biochemically: 22, 31 by far the major part of the overflow of ATP from intact
tissues upon sympathetic nerve stimulation 13–15, 23, 26, 30 comes from non-neural …
Abstract
The vesicles of postganglionic sympathetic axons store both noradrenaline and ATP.22,31 The theory of noradrenaline-ATP co-transmission implies that both compounds are released by nerve action potentials and elicit postjunctional effects. Many properties of postjunctional responses support the theory.3,12,22,27 However, neural release of ATP has been difficult to detect biochemically:22,31 by far the major part of the overflow of ATP from intact tissues upon sympathetic nerve stimulation13–15,23,26,30 comes from non-neural elements, especially smooth muscle and endothelial cells.5,17,19,20,28,30 Here we describe a parallel electrically evoked overflow of [3H]noradrenaline and endogenous ATP from cultured chick sympathetic neurons. The overflow was abolished by tetrodotoxin, ω-conotoxin and withdrawal of Ca2+, was increased by tetraethylammonium and 4-aminopyridine, and was not changed by prazosin or suramin. The results demonstrate directly the action potential-evoked, Ca2+-dependent and presumably vesicular and exocytotic release of ATP from postganglionic sympathetic neurons. They support the co-transmitter theory and suggest that cultured sympathetic neurons are a preparation in which noradrenaline-ATP co-release can be examined free from postjunctional components.
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