Ionic mechanisms of cell volume regulation in leukocytes.

摘要: Mammalian cells, including leukocytes, tend to gain volume passively be­ cause of the presence intracellular charged macromolecules, which are impermeant. This tendency cells swell is counteracted by active extrusion monovalent ions, results in maintenance cellular volume. In fact, many cell types preserve an approximately constant size face variations osmolarity medium. The precise coupling between inward ion leak and outward pumping under both isotonic anisotonic conditions unlikely be fortuitous. Instead, preservation near-normal such a variety suggests that able sense thei.r compensate for departure from optimal, physiologic state. implies existence volume­ sensitive transport pathways mediate net loss solutes when enlarged required shrink vice versa. Under conditions, likely activated minute departures normal Though subtle effective, responses obviously difficult study. several groups have resorted more convenient experimental paradigm investigate regulation this approach, substantial changes imposed abrupt­ ly varying tonicity medium, expectation