Papel do antagonista Brilliant Blue G sobre os neurônios mioentéricos imunorreativos ao receptor P2X7 do íleo de ratos submetidos à isquemia/reperfusão intestinal.

Abstract

PALOMBIT, K. Role of the Brilliant Blue G antagonist on the myenteric neurons immunoreactive for the P2X7 receptor of the rats ileum following the intestinal ischemia/reperfusion. 2014. 128 p. Ph. D. thesis (Morphofunctional Sciences) Instituto de Ciencias Biomedicas, Universidade de Sao Paulo, Sao Paulo, 2014. In the digestive tract ischemia/reperfusion (I/R) causes morphological changes in enteric neurons, release ATP into the extracellular space in response to injury, activating the P2X7 receptor. Studies have shown that injury can be attenuated by Brilliant Blue G (BBG) antagonists of this receptor. In the present work, we analyzed the effects of the BBG antagonist on the P2X7 receptor and rats ileum enteric neurons subjected to I/R. Intestinal ischemia was obtained by ileal vessels obstruction for 45 minutes, followed by reperfusion periods of 0 hour (h), 24 h and 14 days. We used the BBG in I/R 24 h and I/R 14 days groups in dosages of 50 and 100 mg/kg. The I/R 0 h is the group without reperfusion. The neuronal density and the cell body profile were analyzed by immunofluorescence technique. Was also analyzed the protein expression of P2X7 receptor by western blotting, labeling of neutrophils by myeloperoxidase (MPO) reaction, the integrity of the intestinal wall by histology and the intestinal motility. Our results demonstrated that the double labeling P2X7 receptor in myenteric neurons were 100%. There was a decrease in density (neurons/cm 2 ) P2X7-ir, NOSir, NF-ir, ChAT-ir and Hu-ir neurons in I/R 0 h, I/R 24 h and I/R 14 days groups. In I/R groups where the antagonist BBG was injected, the neuronal density was less affected. There was a decrease in the area of the cell body profile in neuronal classes in the I/R groups and recovery profile area of the I/R BBG-50 and I/R BBG-100 groups. There was an increase in the expression of P2X7 receptor and in the number of neutrophils in intestine layers in ischemic groups, and the intestinal motility was decreased. Concluded that I/R affected morphologically and functionally the intestine, and that the effects of I/R were decreased by use of the BBG antagonist, demonstrating a possible neuroprotection and participation of P2X7 receptor in enteric neurons in ischemia.