Effects of experimental ulcerative colitis on myenteric neurons in P2X7-knockout mice

Abstract

The objective was to study the distal colon myenteric plexus and enteric glial cells (EGCs) in P2X7 receptor-de cient (P2X7-/-) animals after experimental ulcerative colitis on. 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) was injected into distal colon of C57BL/6 (WT) and P2X7 receptor gene-de cient (P2X7-/-, KO) animals. Distal colon tissues were analysed 24 h and 4 d after administration. Double immuno uorescence was used for analyses and histology was used for morphological analysis. Quantitative analysis demonstrated 13.9% and 7.1% decreases in the number/ganglia of P2X7 receptor-immunoreactive (ir) in the 24 h-WT/colitis group and 4 d-WT/colitis, respectively. There was no reduction in the number per ganglia of neuronal nitric oxide synthase (nNOS)-ir, choline acetyltransferase (ChAT)-ir and PGP9.5 (pan neuronal)-ir neurons in the 4 d-KO/colitis group. There was a reduction by 19.3% in the number of glial brillary acidic protein (GFAP, EGC)-ir in the 24 h-WT/colitis group and a 19% increase in the number of these cells in the 4 d-WT/colitis group. There were no pro le area changes in neurons in the 24 h groups. In the 4 d-WT/colitis and 4 d-KO/colitis groups, there was an increase in the pro le neuronal area of nNOS, ChAT and PGP9.5. Histological analysis showed hyperaemia, oedema or cellular in ltration in the 24 h-WT/colitis groups and 4 d-WT/colitis groups. The 4 d-KO/colitis groups showed no histological changes.