Effects of Ischemia and Reperfusion on P2X(2) Receptor Expressing Neurons of the Rat Ileum Enteric Nervous System

Author(s)

Paulino, Ariane Silva ^[1] ; Palombit, Kelly ^[1] ; Cavriani, Gabriela ^[2] ; Tavares-de-Lima, Wothan ^[2] ; Mizuno, Marcia Sanae ^[1] ; Marosti, Aline Rosa ^[1] ; da Silva, Marcos Vinicius ^[1] ; Girotti, Priscila Azevedo ^[1] ; Liberti, Edson Aparecido ^[1] ; Castelucci, Patricia ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Anat, Inst Biomed Sci, BR-05508900 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Pharmacol, Inst Biomed Sci, BR-05508900 Sao Paulo - Brazil

• Document type: Journal article
• Source: Digestive Diseases and Sciences; v. 56, n. 8, p. 2262-2275, AUG 2011.
• Web of Science Citations: 20

Abstract

Purpose We investigated the effects of ischemia/reperfusion in the intestine (I/R-i) on purine receptor P2X(2)-immunoreactive (IR) neurons of the rat ileum. Methods The superior mesenteric artery was occluded for 45 min with an atraumatic vascular clamp and animals were sacrificed 4 h later. Neurons of the myenteric and submucosal plexuses were evaluated for immunoreactivity against the P2X(2) receptor, nitric oxide synthase (NOS), choline acetyl transferase (ChAT), calbindin, and calretinin. Results Following I/R-i, we observed a decrease in P2X(2) receptor immunoreactivity in the cytoplasm and surface membranes of neurons of the myenteric and submucosal plexuses. These studies also revealed an absence of calbindin-positive neurons in the I/R-i group. In addition, the colocalization of the P2X(2) receptor with NOS, ChAT, and calretinin immunoreactivity in the myenteric plexus was decreased following I/R-i. Likewise, the colocalization between P2X(2) and calretinin in neurons of the submucosal plexus was also reduced. In the I/R-i group, there was a 55.8% decrease in the density of neurons immunoreactive (IR) for the P2X(2) receptor, a 26.4% reduction in NOS-IR neuron, a 25% reduction in ChAT-IR neuron, and a 47% reduction in calretinin-IR neuron. The density of P2X(2) receptor and calretinin-IR neurons also decreased in the submucosal plexus of the I/R-i group. In the myenteric plexus, P2X(2)-IR, NOS-IR, ChAT-IR and calretinin-IR neurons were reduced in size by 50%, 49.7%, 42%, and 33%, respectively, in the I/R-i group; in the submucosal plexus, P2X(2)-IR and calretinin-IR neurons were reduced in size by 56% and 72.6%, respectively. Conclusions These data demonstrate that ischemia/reperfusion of the intestine affects the expression of the P2X(2) receptor in neurons of the myenteric and submucosal plexus, as well as density and size of neurons in this population. Our findings indicate that I/R-i induces changes in P2X(2)-IR enteric neurons that could result in alterations in intestinal motility. (AU)

• FAPESP's process: 05/04752-0 - Analyses of the distribution and the chemical coding of the P2X2 and P2X7 purine receptors in the ileum and distal colon enteric nervous system of the obese mice
• Grantee: Patricia Castelucci
• Support Opportunities: Regular Research Grants