Effects of myenteric denervation on extracellular matrix fibers and mast cell distribution in normal stomach and gastric lesions

BAC denervation causes an increase in the frequency of reticular and elastic fibers in the denervated (group II) compared to the non-denervated stomachs (group I). The treatment of the animals with MNNG induced the development of adenocarcinomas in non-denervated and denervated stomachs (groups III and IV, respectively) with a notable increase in the relative volume of the stroma, the frequency of reticular fibers and the inflammatory infiltrate that was more intense in group IV. An increase in the frequency of elastic fibers was observed in adenocarcinomas of denervated (group IV) compared to the non-denervated stomachs (group III) that showed degradation of these fibers. The development of lesions (groups III and IV) was also associated with an increase in the mast cell population, especially AB and AB-SAF positives, the latter mainly in the denervated group IV.The results show a strong association in the morphological alteration of the ECM fibrillar components, the increased density of mast cells and the development of tumors induced by MNNG in the non-denervated rat stomach or denervated by BAC. This suggests that the study of extracellular and intracellular components of tumor microenvironment contributes to understanding of tumor biology by action of myenteric denervation.Interaction between tumor cells and the surrounding stroma is one of the key aspects in the mechanism of tumor cell proliferation and invasion [1]. Tumor cells do remodel the extracellular matrix (ECM), a complex mixture of fibers (collagen, reticular and elastic) and ground substance that provides cell support [2], to facilitate communication and escape of the control by the microenvironment [3]. The collagen fibrillar system acts as a supporting framework of tissues, where reticular fibers connect collagen fibers with the basal laminae of epithelial, muscle and adipose cells; the microfibril-elastin system plays a role in uniformly distributing stress to maintain the resilience to local tis