Chloride-dependent pH regulation in connective glial cells of the leech nervous system

We used double-barreled pH-sensitive microelectrodes to study the mechanisms by which the intracellular pH is regulated in the connective glial cells of the medicinal leech. The experiments indicate that a Cl(-)- and HCO3(-)-dependent mechanism mediates some recovery from intracellular alkalosis even in the absence of external Na+. This suggests the presence of Na(+)-independent Cl-/HCO3- exchange in the connective glial membrane. At alkaline pHi, this exchange most likely operates in the direction of net acid loading (i.e. HCO3- efflux).