REDOX STATE OF PYRIDINE-NUCLEOTIDES, BUT NOT GLUTATHIONE, REGULATE CA2-MUSCLE( RELEASE BY H2O2 FROM MITOCHONDRIA OF PULMONARY SMOOTH)

Treatment of bovine pulmonary artery smooth muscle mitochondria with H 2O2 stimulated oxidation of GSH and NAD(P)H along with an increase in Ca2+ release. Addition of oxaloacetate to mitochondrial suspension sti mulated Ca2+ release and oxidation of NAD(P)H while GSH level remained unchanged. Subsequently, addition of beta-hydroxybutyrate which reduc ed mitochondrial pyridine nucleotides caused reuptake of the released Ca2+ without causing appreciable alteration of GSH level. Treatment of the mitochondria with 1,3-bis(2-dichloroethyl)-1-nitrosourea (BCNU), an inhibitor of glutathione reductase, significantly decreased GSH lev el without producing discernible change in Ca2+ release and NAD(P)H ox idation.