Angiotensin II type 2 receptor (AT2 R) localization and antagonist-mediated inhibition of capsaicin responses and neurite outgrowth in human and rat sensory neurons.

Background: The angiotensin II (AngII) receptor subtype 2 (AT2 R) is expressed in sensory neurons and may play a role in nociception and neuronal regeneration.

Methods: We used immunostaining with characterized antibodies to study the localization of AT2 R in cultured human and rat dorsal root ganglion (DRG) neurons and a range of human tissues. The effects of AngII and AT2 R antagonist EMA401 on capsaicin responses in cultured human and rat (DRG) neurons were measured with calcium imaging, on neurite length and density with Gap43 immunostaining, and on cyclic adenosine monophosphate (cAMP) expression using immunofluorescence.

A longitudinal study of sensory biomarkers of progression in patients with diabetic peripheral neuropathy using skin biopsies.

We aimed to identify biomarkers in skin punch biopsies that could be used to monitor progression of diabetic peripheral neuropathy (DPN), and, in future studies, to assess the efficacy of agents that may reduce progression. Patients with DPN were studied with clinical assessments, skin biopsies, quantitative sensory testing (QST), histamine-induced skin flare, nerve conduction studies and contact heat-evoked potentials (CHEPS). Skin biopsies were performed on two visits with a 6 month interval (n=29 patients) to quantify intraepidermal (IENF) and subepidermal (SENF) nerve fibres immunoreactive for: protein gene product 9.

The menthol and cold sensation receptor TRPM8 in normal human nasal mucosa and rhinitis.

Background: Menthol and cold sensation trigger symptoms and reflex responses in the upper airway, but the underlying molecular mechanisms are unknown. We have therefore studied nerve fibres expressing the menthol and cold receptor TRPM8 in normal human mucosa, and in rhinitis. TRPM8 nerve fibres were compared with those expressing other TRP receptors including TRPV1 (capsaicin and heat receptor), and TRPA1 (mechano-cold receptor).

Localisation of SCN10A gene product Na(v)1.8 and novel pain-related ion channels in human heart.

We have shown that the gene SCN10A encoding the sodium channel Na(v)1.8 is a susceptibility factor for heart block and serious ventricular arrhythmia. Since Na(v)1.

Expression of the TRPV1 receptor differs in quiescent inflammatory bowel disease with or without abdominal pain.

Objective: Transient receptor potential vanilloid type 1 (TRPV1) has been shown to play an important role in visceral hypersensitivity. A significant proportion of patients with inflammatory bowel disease (IBD) continue to complain of abdominal pain despite their disease being otherwise quiescent. We investigated TRPV1-immunoreactive fibres in rectosigmoid biopsies taken from such patients with correlation to abdominal pain severity.