Effect of Muscarine and Atropine on the production of myeloperoxidase and proinflammatory cytokines in small intestine

Abstract

Abstract The cholinergic system it’s known as a modulator of the intestinal immune system. The aim of this work was to analyze the impact of muscarine and atropine on the production of myeloperoxidase (MPO) on lamina propia of small intestine as well as other local effects, like stimulation of goblet cells and mucus secretion. Three groups of male BALB/c mice were administred by i.p. route: a) control (SS), b) atropine (4 mg/kg) and c) muscarine (50 ng/kg). At 7 day of treatment, histological samples were obtained for Naphtol AS-D method to MPO activity analysis, immunofluorescence assay to localize MPO secreting cells and Flow Cytometry for intracellular TNF-α, IFN-γ, IL-2 and IL-6 measures. In the analysis of the histological samples it was observed that in the group treated with muscarine the number and size of goblet cells and mucus were augmented in the lumen. The number of neutrophils in the villus was also augmented in the muscarine group in comparison of treated with atropine. On the other hand, the immunofluorescence had an increased number of positive cells and activity in tissue to MPO in the muscarine group. In the Flow Cytometry analysis for lamina propia and Peyer’s patches, IFN-γ and TNF-α were augmented in the muscarine group, while IL-2 and IL-6 decreased. In this study, the MPO can be regulates immune functions such as increasing cytokines in macrophages and endothelial cells, also suppressing DC’s function of antigen presentation and switch to adaptive immunity which can lead to more innate response, and increased production of proinflamatory cytokines by lymphocytes.