TRPA1 - "TRPA1 activation by allyl isothiocyanate recorded on the Port-a-Patch"
Transient receptor potential (TRP) channels are an important class of receptors found widely distributed throughout the mammalian central and peripheral nervous systems. They have been shown to be activated by many stimuli including temperature, mechano-stimulation, divalent cations and pH, amongst others. TRP channels are receiving much attention as potential targets for the treatment of, for example, pain, respiratory diseases such as asthma, cancer and immune disorders (for review see ref. 1). The TRPA1 receptor was first cloned from cultured human lung fibroblasts but has subsequently been found to be expressed in sensory neurones and is often found co-localised with TRPV1. TRPA1 is activated by a number of chemical stimuli including allyl isothiocyanate (mustard oil), cinnamaldehyde (the active ingredient of cinnamon), chlorobenzylidene malononitrile (CS tear gas), hydrogen peroxide and hyperchlorite (chlorine gas). It is thought that TRPA1, together with TRPV1, may contribute to chemical hypersensitivity, chronic cough, and airway inflammation in asthma. Here we present data recorded on the Port-aPatch with external perfusion showing recordings of human TRPA1 (hTRPA1) activated by increasing concentrations of allyl isothiocyanate (AITC). hTRPA1 could be repetitively stimulated using low concentrations of AITC but was desensitized by high concentrations of AITC (>10 µM).