Effects of Chemoexcitatory Agents on K+ Currents of Isolated Type I Cells from Neonatal Rat Carotid Body

The ability of the carotid bodies to detect changes in arterial oxygen, carbon dioxide, and pH levels is well documented, and there is much evidence to support the idea that the catecholamine-containing type I glomus cells of the carotid body are the primary chemosensory element (1). However, the cellular mechanisms by which the carotid body transduces a change in arterial gas or pH levels into altered carotid sinus nerve activity are almost completely unknown. As ion channels play fundamental roles in stimulus-response coupling in all sensory cells studied thus far, it is of obvious importance to investigate the classes of ion channels present in type I cells and their possible roles in chemotransduction. Here we report electrophysiological studies of ionic currents recorded in isolated neonatal rat type I cells using the whole-cell patch-clamp technique (2).