Jejunal afferent nerve sensitivity in wild‐type and TRPV1 knockout mice

• DOI: 10.1113/jphysiol.2004.071746
• Publication Date: 2004-08-27T00:13:00Z
• Authors: Weifang Rong; Kirk Hillsley; John B. Davis; Gareth Hicks; Wendy J. Winchester; David Grundy
• Keywords: Capsazepine; Capsaicin; Knockout mouse

The aim of this study was to investigate the contribution TRPV1 receptor jejunal afferent sensitivity in murine intestine. Multiunit activity recorded vitro from mesenteric afferents supplying segments mouse jejunum taken wild-type (WT) and knockout (TRPV1(-/-)) animals. In WT preparations, ramp distension gut (up 60 mmHg) produced biphasic changes so pressure-response curve had an initial rapid increase discharge followed by a second phase slower activity. Afferent response significantly lower TRPV1(-/-) than mice. Single-unit analysis revealed three functional types fibres: (1) low-threshold fibres (2) wide dynamic range (3) high-threshold fibres. There marked downward shift for mice as compared controls. intraluminal hydrochloric acid (20 mM) also attenuated contrast, bath application bradykinin (1 microm, 3 ml) not different between two groups. antagonist capsazepine (10 microm) nerve responses distension, bradykinin, well spontaneous responded capsaicin with increases activity, whereas were at all sensitive capsaicin. Previous evidence indicates that is mechanosensitive, results present suggest activation may sensitize small intestinal neurones.