Colocalization of substance P with tumor necrosis factor-α in the lymphocytes and mast cells in gastritis in experimental rats

Abstract

Substance P (SP) elicits numerous potent neuroimmunomodulatory effects, increasing the release of tumor necrosis factor alpha (TNF-α). The study aimed to investigate immunoneural communication in experimentally-induced gastritis in rats. SP-containing nerve fibers and lymphocytes and mast cells were counted in the mucosa of the stomachs of rats using double immunohistochemical and confocal laser microscopic methods, proving colocalization of SP and TNF-α in the lymphocytes and mast cells. In controls, only the nerve fibers showed SP immunoreactivity (IR). However, in gastritis the number of SP-IR fibers and TNF-α IR lymphocytes and mast cells increased significantly (P < 0.001); SP-IR fibers were seen in close contact with lymphocytes and mast cells. Numerous lymphocytes (13.1%) and mast cells (10.8%) showed IR for both SP and TNF-α (colocalization) within the same cells. SP release from nerve fibers, lymphocytes and mast cells together with TNF-α can enhance the development of gastric inflammation and participate in tissue damage in gastritis.