Muscarinic receptor regulation of osmosensitive taurine transport in human SH‐SY5Y neuroblastoma cells

Abstract

When exposed to hypoosmotic stress, cells initially swell in proportion to the reduction in osmolarity and then normalize their volume via a process known as regulatory volume decrease. The latter involves the release of osmolytes, both inorganic (K + and Cl ) ) and organic (amino acids, polyols, and methylamines) and the exit of obligated water (McManus et al. 1995). Although inorganic osmolytes constitute the quantitatively major fraction of the osmolyte pool (60-65%; Pasantes-Morales et al. 2002), large changes in ion concentration can adversely impact cell excitability. Thus, the pool of 'non-perturbing' organic osmolytes plays a pivotal role in countering changes in osmolarity without compromising cell function. One of the most quantitatively important organic