Expression of hexose-6-phosphate dehydrogenase in rat tissues

Introduction: Hexose-6-phosphate dehydrogenase (H6PDH) is the main NADPH generating enzyme in the lumen of the endoplasmic reticulum. H6PDH is regarded as an ancillary enzyme in prereceptorial glucocorticoid activation and probably acts as a nutrient sensor and as a prosurvival factor. Methods: H6PDH expression was determined in a variety of rat and human tissues by detecting mRNA and protein levels, and by measuring its dehydrogenase and lactonase activities. Results: It was found that H6PDH was present in all investigated tissues; both expression and activity remained within an order of magnitude. Correlation was found between the dehydrogenase activity and protein or mRNA levels. Conclusion: The wide tissue distribution confirmed the supposed housekeeping feature of the enzyme