Stimulation of the hexose monophosphate shunt in bovine ciliary body under oxidative stress

The effect of t-butyl hydroperoxide (TBHP) on the oxidation of C1-radiolabeled glucose and C6-radiolabeled glucose by bovine ciliary body was investigated in the presence and absence of the glutathione reductase inhibitors nitrofurantoin (NF) and 1,3-bis(2-chloroethyl)-1-nitrosourea [BCNU]. 14CO2 production from 1-14C-glucose was markedly stimulated by TBHP and inhibited by BCNU. Using tissue extracts, BCNU was shown to inhibit both glutathione reductase and glucose-6-phosphate dehydrogenase. These results support the hypothesis that bovine ciliary body has high NADPH regenerating capacity by the hexose monophosphate shunt.