11Hydroxydehydrogenase

11-Hydroxydehydrogenase, also known as 11-beta-hydroxysteroid dehydrogenase (11-beta-HSD), refers to a family of enzymes that play a crucial role in the metabolism of steroid hormones. There are two main isoforms, 11-beta-HSD1 and 11-beta-HSD2. These enzymes are responsible for interconverting active and inactive forms of glucocorticoids and mineralocorticoids.

11-beta-HSD1 primarily acts as a reductase, converting inactive glucocorticoids like cortisone into their active forms, such as cortisol. This occurs mainly in tissues like the liver, adipose tissue, and brain, where it regulates local glucocorticoid activity. Conversely, 11-beta-HSD2 generally functions as an oxidase, converting active glucocorticoids into inactive forms. This isoform is predominantly found in mineralocorticoid-sensitive tissues, such as the kidneys and salivary glands.

The activity of 11-beta-HSD enzymes is vital for maintaining hormonal balance and preventing the overstimulation of glucocorticoid receptors by mineralocorticoids in tissues where they are not intended to bind. Dysregulation of 11-beta-HSD1 has been implicated in metabolic disorders like obesity, type 2 diabetes, and metabolic syndrome. Conversely, defects in 11-beta-HSD2 can lead to conditions like apparent mineralocorticoid excess syndrome. Research into these enzymes continues to explore their therapeutic potential for various diseases.