Effects of low ozone-oxygen concentrations on the acetylcholine release atthe mouse neuromuscular junction

The use of a mixture of low concentrations of ozone (O-3) with oxygen (O-2) have been proved to be useful in different human pathological conditions. Owing to a lack of both pharmacological and epidemiological basic studies, the scientific consideration of this therapeutic potential is still inappro priate. Here, we started, from an electrophysiological point of view, a stu dy on the possible effects of low O-3 doses on the acetylcholine (ACh) rele ase at the neuromuscular junction. Indeed, some experimental conditions ind icate a positive effect either in maintaining cytosolic calcium (Ca2+) home ostasis or in increasing the efficacy of the intracellular antioxidant syst ems. Furthermore, a positive action on the kinetics of some antioxidant enz ymes must be taken into account as a possible molecular mechanism in the re gulation of the function of cellular homeostasis. Our data demonstrate a re duction of evoked ACh release in the mouse neuromuscular junction. O-3 affe cts neither the spontaneous ACh release nor the kinetics of the ACh-recepto r-channel complex. The results are compatible with a reduction of intracell ular Ca2+ and proved a molecular action of O-3. (C) 1999 Elsevier Science I nc. All rights reserved.