TRPA1 channels: Novel targets of 1,4-dihydropyridines

Caffeine activates mouse TRPA1 channels but suppresses human TRPA1 channels.

Caffeine has various well-characterized pharmacological effects, but in mammals there are no known plasma membrane receptors or ion channels activated by caffeine. We observed that caffeine activates mouse transient receptor potential A1 (TRPA1) in heterologous expression systems by Ca(2+)(i) imaging and electrophysiological analyses. These responses to caffeine were confirmed in acutely dissoc...

Zinc activates damage-sensing TRPA1 ion channels.

Zinc is an essential biological trace element. It is required for the structure or function of over 300 proteins, and it is increasingly recognized for its role in cell signaling. However, high concentrations of zinc have cytotoxic effects, and overexposure to zinc can cause pain and inflammation through unknown mechanisms. Here we show that zinc excites nociceptive somatosensory neurons and ca...

Trpa1 Channels in Visceral Inflammation and Pain

Nonmodal gating of cardiac calcium channels as revealed by dihydropyridines

The hypothesis that dihydropyridine (DHP)-sensitive calcium channels have three distinct modes of gating has been examined. The major prediction is that the relative frequencies among modes depend on DHP concentration while the kinetics within a mode do not. We tested this by studying whole-cell and single-channel calcium currents in neonatal rat and adult guinea pig cardiac myocytes in differe...

TRPA1 channels: chemical and temperature sensitivity.

Transient receptor potential ankyrin 1 (TRPA1) is a polymodal excitatory ion channel found in sensory neurons of different organisms, ranging from worms to humans. Since its discovery as an uncharacterized transmembrane protein in human fibroblasts, TRPA1 has become one of the most intensively studied ion channels. Its function has been linked to regulation of heat and cold perception, mechanos...