Distribution of the P2X2 receptor and chemical coding in the ileum enteric neurons of the obese male mouse (ob/ob)

• Grant number: 14/13005-3
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: August 01, 2014
• End date: January 31, 2015
• Field of knowledge: Biological Sciences - Morphology - Anatomy
• Principal Investigator: Patricia Castelucci
• Grantee: Patricia Castelucci
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

AIM: We investigate the colocalization, density and profile of neuronal areas enteric neurons in the ileum male obese mice. METHODS: The small intestine gut of male mice in the obese group (OG) (C57BL/6J ob/ob) and the control group (CG) (+/+) were used. The tissues were analyzed with a double immunostaining technique for the P2X2 receptor with NOS (nitric oxide synthase), ChAT (Choline acetyl transferase) and CalR (calretinin) immunoreactivity (IR). Also, we investigate the density and profile of neuronal areas of the NOS-, ChAT- and Calr-IR neurons in the myenteric neurons. In addition, enteric neurons were labeled using a nicotinamide adenine dinucleotide (NADH) diaphorase method. RESULTS: The qualitative analysis demonstrated P2X2 receptor expression in the cytoplasm and in the nuclear and plasmatic membranes only in the CG. Neuronal density values (neuron/cm2) were decreased 31% (CG 6,579 ± 837; OG 4,556 ± 407) and 16.5% (CG 7,796 ± 528; OG 6,513 ± 610) in the NOS-IR and Calr-IR neurons in the OG, respectively (P < 0.05). The density of ChAT-IR (CG 6,200 ± 310; OG 8,125 ± 749) neurons significantly increased 31% in the OG (P < 0.05). Neuron size studies demonstrated that NOS, ChAT, and Calr-IR neurons did not change between the CG and OG groups. The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG. CONCLUSION: The male ob/ob mice used may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-IR, ChAT-IR and CalR-IR myenteric neurons. (AU)