Endocrine Abstracts

Excessive glucocorticoid exposure has been implicated in the pathogenesis of obesity and the metabolic syndrome. The in vivo conversion of inactive to active glucocorticoids is catalysed by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), requiring NADPH as a cofactor. Hexose-6-phosphate dehydrogenase (H6PDH) is co-localised with 11β-HSD1 in the lumen of the endoplasmic reticulum and controls local NADPH availability. Thus H6PDH plays an important role...

NADPH generated by hexose-6-phosphate dehydrogenase (H6PDH) within the lumen of the endoplasmic reticulum (ER) drives the reductase activity of 11β-hydroxysteroid dehydrogenase type 1 (11-βHSD1) allowing the production of active glucocorticoids. H6PDH knockout (H6PDHKO) mice develop a vacuolating myopathy, reduced muscle mass and display activation of the ER stress response. However, the role of glucocorticoids and 11β-HSD1 in the myopathy phenotype is not clear...

In humans, glucocorticoids (GC) are implicated in the pathogenesis of obesity and insulin resistance. GCs are regulated at the prereceptor level by 11beta-hydroxysteroid dehydrogenases (11β-HSD). 11β-HSD type 1 (11β-HSD1) predominantly displays oxo-reductase activity, converting cortisone in man, 11-dehydrocorticosterone in rodents, to cortisol and corticosterone respectively – a reaction requiring the cofactor NADPH. The generation of a hexose-6-phosphate ...

Glucocorticoid (GC) hormone action can be modulated at the pre-receptor level by the endoluminal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1). 11βHSD1 is a bidirectional enzyme that primarily acts as an oxo-reductase in vivo, converting the pro-hormone cortisone to its active form cortisol, while its dehydrogenase activity results in inactivation of cortisol to cortisone. 11βHSD1 oxo-reductase activity allows GC reactivation in a tissue s...

Ion and fluid transport mechanisms within the eye are important for several key physiological processes including the maintenance of corneal transparency and the regulation of intraocular pressure (IOP). The mechanism involved in epithelial sodium transport in the eye is regulated by corticosteroids and at a pre-receptor level, by 11β-hydroxysteroid dehydrogenase (11β-HSD) activity. Recent studies localised type 1 (11β-HSD1), an oxo-reductase that activates cort...