Interaction of 11 beta-hydroxysteroid-oxido reductase in different organs of various mammalian species.
Distribution of 11 beta-HSOR activity in different organs has been measured using tissue slices, homogenates, and microsomes. The biological material was incubated in vitro with cortisol/ cortisone (human preparations) or corticosterone/11-dehydrocorticosterone, respectively (animal preparations). Metabolites formed were quantified using RP-HPLC and on-line detection of labeled compounds. The typical pattern of CS-metabolism as obtained with rat tissue slices revealed that testis, rectum and kidney are predominant oxidizers of active gluco-CS, while liver and lung mainly function as reducers. Human placenta preparations display an exclusive oxidase activity. To trace different types of 11 beta-HSOR homogenates and microsomes of various organs were incubated with different cosubstrates (NAD+/NADH or NADP+/ NADPH, respectively). In accordance with previous reports, this study found that isoenzymes with different cosubstrate preferences exist in individual organs. 11 beta-HS oxidase activity displays a NAD+ preference in the human placenta. There was no apparent difference in cosubstrate preference between human and guinea pig placenta homogenates. In mice there is also a detectable reductive activity, whereas the Sprague-Dawley rat and golden hamster do not show any detectable activities.
Stahl
K
K
Institut für Klinische Physiologie, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany.
Lichtenstein
I
I
Siebe
H
H
Hierholzer
K
K
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000818:Animals; D006224:Cricetinae; D004790:Enzyme Induction / Q000502:physiology; D005260:Female; D005333:Fetus / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008647:Mesocricetus; D051379:Mice; D008861:Microsomes / Q000201:enzymology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D013045:Species Specificity; D014018:Tissue Distribution
D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases