Role of Na+-K+-Cl- cotransport and Na+/Ca2+ exchange in mitochondrial dysfunction in astrocytes following in vitro ischemia.

Na(+)-K(+)-Cl(-) cotransporter isoform 1 (NKCC1) and reverse mode operation of the Na(+)/Ca(2+) exchanger (NCX) contribute to intracellular Na(+) and Ca(2+) overload in astrocytes following oxygen-glucose deprivation (OGD) and reoxygenation (REOX). Here, we further investigated whether NKCC1 and NCX play a role in mitochondrial Ca(2+) (Ca(m)(2+)) overload and dysfunction. OGD/REOX caused a doubling of mitochondrial-releasable Ca(2+) (P < 0.

Increased tolerance to oxygen and glucose deprivation in astrocytes from Na(+)/H(+) exchanger isoform 1 null mice.

The ubiquitously expressed Na(+)/H(+) exchanger isoform 1 (NHE1) functions as a major intracellular pH (pH(i)) regulatory mechanism in many cell types, and in some tissues its activity may contribute to ischemic injury. In the present study, cortical astrocyte cultures from wild-type (NHE1(+/+)) and NHE1-deficient (NHE1(-/-)) mice were used to investigate the role of NHE1 in pH(i) recovery and ischemic injury in astrocytes. In the absence of HCO(3)(-), the mean resting pH(i) levels were 6.