Increased production of 11beta-hydroxysteroid dehydrogenase type 2 in the kidney microsomes of squirrel monkeys (Saimiri spp.)

In squirrel monkeys (Saimiri spp.), cortisol circulates at levels much higher than those seen in man and other Old World primates, but squirrel monkeys exhibit no physiologic signs of the mineralocorticoid effects of cortisol. These observations suggest that squirrel monkeys have mechanisms for protection of the mineralocorticoid receptor (MR) from these high levels of cortisol. We previously showed that the serum cortisol to cortisone ratio in these animals is low relative to that in human serum, suggesting that production of the MR protective enzyme, 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), is increased in squirrel monkeys. Here, we directly evaluate whether increased production of 11beta-HSD2, which inactivates cortisol to cortisone, is a mechanism for protection of MR. In vitro assays showed that 11beta-HSD2 activity in squirrel monkey kidney microsomes was 3 to 7 times higher than that seen in kidney microsomes from pig or rabbit. 11beta-HSD2 protein detected by Western blot analysis was 4 to 9 times greater in squirrel monkey microsomes than in pig or rabbit microsomes. Comparison of the effect of expression of either human or squirrel monkey 11beta-HSD2 on MR transactivation activity showed similar inhibition of MR response to cortisol by both enzymes, indicating that the intrinsic activities of the human and squirrel monkey enzymes are similar. These findings suggest that one mechanism by which squirrel monkeys protect the MR from activation by high cortisol levels in the kidney is by upregulation of 11beta-HSD2 activity through increased production of the enzyme.     

Tissue localization of 11 beta-hydroxysteroid dehydrogenase and its relationship to the glucocorticoid receptor.

11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) dictates specificity for the mineralocorticoid receptor (MR) by converting the active steroid cortisol to cortisone in man (corticosterone to 11-dehydrocorticosterone in rodents), leaving aldosterone to occupy the MR. However cortisol is the principal circulating glucocorticoid in man and 11 beta-HSD, distributed in a tissue specific fashion, may represent a powerful mechanism in regulating exposure of active steroid to the glucocorticoid receptor (GR). A detailed localization study of 11 beta-HSD gene expression and activity in numerous rat tissues has been performed and compared with the presence of GR mRNA. 11 beta-HSD mRNA (1.4 kB) measured by hybridization to a cDNA derived from hepatic 11 beta-HSD, and enzyme activity, measured by percentage conversion of [3H]corticosterone to [3H]11-dehydrocorticosterone by tissue homogenate, was widespread, present in all tissues studied except spleen, brain cortex and heart. There was a close correlation between tissue 11 beta-HSD mRNA levels and activity (r = 0.91, P less than 0.001) suggesting pretranslational regulation of the enzyme at a tissue level. There was also close co-localization of GR mRNA (7 kB), measured by hybridization to a rat GR cRNA probe, and enzyme mRNA/activity in every tissue studied except heart and brain cortex in which GR mRNA was found. In the mineralocorticoid target tissues kidney and colon, additional 11 beta-HSD mRNA bands were seen (kidney 1.8 kB, colon 3.4 kB), suggesting the presence of multiple dehydrogenase species. 11 beta-HSD is widely distributed and suitably placed to modulate ligand occupancy of the GR. The possibility of multiple dehydrogenase species in mineralocorticoid target tissues is consistent with the hypothesis that the ubiquitous 'native' 1.4 kB hepatic enzyme regulates the GR, and these separate dehydrogenases regulate the MR.     

The crystal structure of guinea pig 11beta-hydroxysteroid dehydrogenase type 1 provides a model for enzyme-lipid bilayer interactions

The metabolic reduction of 11-keto groups in glucocorticoid steroids such as cortisone leads to the nuclear receptor ligand cortisol. This conversion is an example of pre-receptor regulation and constitutes a novel pharmacological target for the treatment of metabolic disorders such as insulin resistance and possibly other derangements observed in the metabolic syndrome, such as hyperlipidemia, hypertension, and lowered insulin secretion. This reaction is carried out by the NADPH-dependent type 1 11beta-hydroxysteroid dehydrogenase (11beta-HSD1), an enzyme attached through an integral N-terminal transmembrane helix to the lipid bilayer and located with its active site within the lumen of the endoplasmic reticulum. Here we report the crystal structure of recombinant guinea pig 11beta-HSD1. This variant was determined in complex with NADP at 2.5 A resolution and crystallized in the presence of detergent and guanidinium hydrochloride. The overall structure of guinea pig 11beta-HSD1 shows a clear relationship to other members of the superfamily of short-chain dehydrogenases/reductases but harbors a unique C-terminal helical segment that fulfills three essential functions and accordingly is involved in subunit interactions, contributes to active site architecture, and is necessary for lipid-membrane interactions. The structure provides a model for enzyme-lipid bilayer interactions and suggests a funneling of lipophilic substrates such as steroid hormones from the hydrophobic membrane environment to the enzyme active site.     

The role of progesterone metabolism and androgen synthesis in renal blood pressure regulation.

11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) plays a crucial role in converting hormonally active cortisol into inactive cortisone, conferring specificity onto the human mineralocorticoid receptor (MR). Progesterone binds with even higher affinity to the MR, but acts as an MR antagonist. How aldosterone is able to keep its function as predominant MR ligand in clinical situations with high progesterone concentrations, such as pregnancy, is not clear. We have shown in vitro that the human kidney possesses an effective enzyme system that metabolizes progesterone to inactive metabolites in a process similar to the inactivation of cortisol by 11beta-HSD2. In studies on patients with adrenal insufficiency, we have shown that the in vivo anti-mineralocorticoid activity of progesterone is diminished by inactivating metabolism of progesterone, local formation of the deoxycorticosterone mineralocorticoid from progesterone, and inhibition of 11beta-HSD2 by progesterone and its metabolites resulting in decreased inactivation of cortisol and hence increased MR binding by cortisol. The enzymes involved in progesterone metabolism are also responsible for the capability of the human kidney to convert pregnenolone to DHEA and androstenedione leading to the formation of active androgens, testosterone and 5alpha-DH-testosterone. Locally produced androgens might be responsible for the observed difference in blood pressure between men and women and higher susceptibility to hypertension in men.     

11 Beta-hydroxysteroid dehydrogenase type 1 is induced in human monocytes upon differentiation to macrophages.

11beta-hydroxysteroid dehydrogenases (11beta-HSD) perform prereceptor metabolism of glucocorticoids through interconversion of the active glucocorticoid, cortisol, with inactive cortisone. Although the immunosuppressive and anti-inflammatory activities of glucocorticoids are well documented, the expression of 11beta-HSD enzymes in immune cells is not well understood. Here we demonstrate that 11beta-HSD1, which converts cortisone to cortisol, is expressed only upon differentiation of human monocytes to macrophages. 11beta-HSD1 expression is concomitant with the emergence of peroxisome proliferator activating receptor gamma, which was used as a surrogate marker of monocyte differentiation. The type 2 enzyme, 11beta-HSD2, which converts cortisol to cortisone, was not detectable in either monocytes or cultured macrophages. Incubation of monocytes with IL-4 or IL-13 induced 11beta-HSD1 activity by up to 10-fold. IFN-gamma, a known functional antagonist of IL-4 and IL-13, suppressed the induction of 11beta-HSD1 by these cytokines. THP-1 cells, a human macrophage-like cell line, expressed 11beta-HSD1 and low levels of 11beta-HSD2. The expression of 11beta-HSD1 in these cells is up-regulated 4-fold by LPS. In summary, we have shown strong expression of 11beta-HSD1 in cultured human macrophages and THP-1 cells. The presence of the enzyme in these cells suggests that it may play a role in regulating the immune function of these cells.     

The 11beta hydroxysteroid dehydrogenase 2 exists as an inactive dimer

The 11beta-hydroxysteroid dehydrogenase types 1 and 2 enzymes (11beta-HSD1 and 11beta-HSD2), modulate glucocorticoid occupation of the mineralocorticoid and glucocorticoid receptors by interconverting corticosterone and cortisol to the inactive metabolites 11-dehydrocorticosterone and cortisone within the target cells. The NAD(+)-dependent 11-HSD 2 in the kidney inactivates corticosterone and cortisol, allowing aldosterone, which is not metabolized, access to the receptor. Studies of the kinetics of 11-HSD 2 activity in the rat kidney have produced inconsistent results. Western blots done in the absence of the reducing agent beta-mercaptoethanol showed two bands with approximate MW of 40 and 80 kDa. When beta-mercaptoethanol was used, only the 40 kDa was detected, indicating that under non-denaturing conditions a significant proportion of the 11beta-HSD 2 exists as a dimer. NAD(+)-dependent conversion of 3H-corticosterone by 20 microg of microsomal protein increased approximately 10 fold with the addition of 5 mM DTT concentration. NADP(+)-dependent activity with 20 microg of microsomal protein was very low and did not change significantly when using DTT. In the presence of DTT, the predominant 11-HSD activity in the rat kidney is NAD(+)-dependent with a K(m) of 15.1 nM, similar to that of the cloned and expressed enzyme. These data suggest that dimerization and subsequent enzyme inactivation occur when protocols promoting oxidation of this protein are used.     

11β—羟基类固醇脱氢酶

现已发现两型１１β－羟基因固醇脱氢酶（１１β－ＨＳＤ）：１１β－ＨＳＤ１为氧化还原酶,催化皮质醇与其代谢产物之间的相互转化;１１β－ＨＳＤ２则为专一氧化酶,只催化皮质醇的失活。１１β－ＨＳＤ１在体内分布广泛,功能目前沿不清楚。１１β－ＨＳＤ２主要存在于盐皮质激素靶器官,肾脏１１β－ＨＳＤ２通过降解糖皮质激素保护盐皮质激素受体的特异性,肾脏此酶的缺乏,可以导致严重高血压。胎盘１１β－ＨＳＤ２通过降解     

Human 11beta-hydroxysteroid dehydrogenase type 1 is enzymatically active in its nonglycosylated form

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD 1) is a microsomal enzyme responsible for the reversible interconversion of active 11beta-hydroxyglucocorticoids into inactive 11-ketosteroids and by this mechanism regulates access of glucocorticoids to the glucocorticoid receptor. The enzyme has also been proven to participate in xenobiotic carbonyl compound detoxification. 11beta-HSD 1 is anchored within the membranes of the endoplasmic reticulum (ER) by its N-terminus, whereby its active site protrudes into the lumen of the ER. In the primary structure of 11beta-HSD 1 three Asn-X-Ser glycosylation motifs have been identified. However, the importance of N-linked glycosylation of 11beta-HSD 1 for catalytic activity has been controversely discussed. To clarify if glycosylation is essential for enzyme activity, we performed deglycosylation experiments of native 11beta-HSD 1 from human liver as well as site-directed mutagenesis to remove potential glycosylation sites upon overexpression in Pichia pastoris. The altered proteins were examined regarding their catalytic activity towards their physiological glucocorticoid substrates. The molecular size of the various 11beta-HSD 1 forms was analyzed by immunoblotting with a polyclonal antibody raised against 11beta-HSD 1 protein from human liver. By stepwise enzymatic deglycosylation of native 11beta-HSD 1 we could demonstrate that all potential glycosylation sites carry N-linked oligosaccharide residues under physiological conditions. Interestingly, complete deglycosylation did not affect enzyme activity, neither in the reductive (cortisone) nor in the oxidative (cortisol) direction. Upon overexpression in the yeast P. pastoris, 11beta-HSD 1 did not undergo glycosylation, but, in spite of this, yielded a fully active enzyme. Our results conclusively demonstrate that 11beta-HSD 1 does not need to be glycosylated to perform its physiological role as glucocorticoid oxidoreductase.     

Regulated expression by PPARalpha and unique localization of 17beta-hydroxysteroid dehydrogenase type 11 protein in mouse intestine and liver

17beta-Hydroxysteroid dehydrogenase type 11 (17beta-HSD11) is a member of the short-chain dehydrogenase/reductase family involved in the activation and inactivation of sex steroid hormones. We recently identified 17beta-HSD11 as a gene that is efficiently regulated by peroxisome proliferator-activated receptor-alpha PPARalpha in the intestine and the liver [Motojima K (2004) Eur J Biochem271, 4141-4146]. In this study, we characterized 17beta-HSD11 at the protein level to obtain information about its physiologic role in the intestine and liver. For this purpose, specific antibodies against 17beta-HSD11 were obtained. Western blotting analysis showed that administration of a peroxisome proliferator-activated receptor-alpha agonist induced 17beta-HSD11 protein in the jejunum but not in the colon, and to a much higher extent than in the liver of mice. A subcellular localization study using Chinese hamster ovary cells and green fluorescent protein-tagged 17beta-HSD11 showed that it was mostly localized in the endoplasmic reticulum under normal conditions, whereas it was concentrated on lipid droplets when they were induced. A pulse-chase experiment suggested that 17beta-HSD11 was redistributed to the lipid droplets via the endoplasmic reticulum. Immunohistochemical analysis using tissue sections showed that 17beta-HSD11 was induced mostly in intestinal epithelia and hepatocytes, with heterogeneous localization both in the cytoplasm and in vesicular structures. A subcellular fractionation study of liver homogenates confirmed that 17beta-HSD11 was localized mostly in the endoplasmic reticulum when mice were fed a normal diet, but was distributed in both the endoplasmic reticulum and the lipid droplets of which formation was induced by feeding a diet containing a proliferator-activated receptor-alpha agonist. Taken together, these data indicate that 17beta-HSD11 localizes both in the endoplasmic reticulum and in lipid droplets, depending on physiologic conditions, and that lipid droplet 17beta-HSD11 is not merely an endoplasmic reticulum contaminant or a nonphysiologically associated protein in the cultured cells, but a bona fide protein component of the membranes of both intracellular compartments.     

The use of deuterium-labeled cortisol for in vivo evaluation of renal 11beta-HSD activity in man: urinary excretion of cortisol, cortisone and their A-ring reduced metabolites

This study describes a new approach using stable isotope methodology in evaluating 11beta-HSD activities in vivo based on urinary excretion of cortisol, cortisone, and their A-ring reduced metabolites. The method involved the measurement of deuterium-labeled cortisol and its deuterium-labeled metabolites by GC/MS simultaneously with endogenous cortisol, cortisone, and their A-ring reduced metabolites after oral administration of deuterium-labeled cortisol to normal human subjects. This stable isotope approach offered unique advantages in assessing the appropriateness of measuring unconjugated and total (unconjugated + conjugated) cortisol, cortisone, and their A-ring reduced metabolites in urine as indices of renal 11beta-HSD2 activity in man. Our results strongly support that the measurement of urinary unconjugated cortisol and cortisone is a significant advance in assessing 11beta-HSD2 activity.     

ATP stimulates human placental 11beta-hydroxysteroid dehydrogenase type 2 activity by a novel mechanism independent of phosphorylation.

The human placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) is believed to play a key role in fetal development since this enzyme protects the fetus from exposure to high levels of maternal cortisol by virtue of converting maternal cortisol to its inert metabolite cortisone. The present study was undertaken to examine the effect of ATP on 11beta-HSD2 activity in human placental microsomes. Enzyme activity, reflected by the rate of conversion of cortisol to cortisone, was stimulated more than six-fold by 0.5 mM ATP (EC(50) = 0.2 mM). Such stimulation appears to be mediated through a novel mechanism independent of ATP-induced phosphorylation of the reaction components since AMP-PNP, a non-hydrolyzable analogue of ATP, was equally effective. The ATP-induced stimulation of 11beta-HSD2 activity is adenine nucleotide specific in that a similar stimulation was observed with ADP and AMP but not with CTP, GTP, or UTP. Furthermore, ATP increased the maximal velocity (V(max)) of the 11beta-HSD2 catalyzed conversion of cortisol to cortisone without altering the apparent K(m) of 11beta-HSD2 for cortisol, suggesting that ATP may stimulate enzyme activity by interacting with the enzyme at a site other than that involved in substrate binding. In conclusion, the present study has identified ATP as a novel regulator of human placental 11beta-HSD2 in vitro. It is conceivable that intracellular ATP may have a profound effect on 11beta-HSD2 function in vivo.     

The 11 beta-hydroxysteroid dehydrogenase type 2 activity in human placental microsomes is inactivated by zinc and the sulfhydryl modifying reagent N-ethylmaleimide

Proper glucocorticoid exposure in utero is vital to normal fetal organ growth and maturation. The human placental 11 beta-hydroxysteroid dehydrogenase type 2 enzyme (11 beta-HSD2) catalyzes the unidirectional conversion of cortisol to its inert metabolite cortisone, thereby controlling fetal exposure to maternal cortisol. The present study examined the effect of zinc and the relatively specific sulfhydryl modifying reagent N-ethylmaleimide (NEM) on the activity of 11 beta-HSD2 in human placental microsomes. Enzyme activity, reflected by the rate of conversion of cortisol to cortisone, was inactivated by NEM (IC(50)=10 microM), while the activity was markedly increased by the sulfhydryl protecting reagent dithiothreitol (DTT; EC(50)=1 mM). Furthermore, DTT blocked the NEM-induced inhibition of 11 beta-HSD2 activity. Taken together, these results suggested that the sulfhydryl (SH) group(s) of the microsomal 11 beta-HSD2 may be critical for enzyme activity. Zn(2+) also inactivated enzyme activity (IC(50)=2.5 microM), but through a novel mechanism not involving the SH groups. In addition, prior incubation of human placental microsomes with NAD(+) (cofactor) but not cortisol (substrate) resulted in a concentration-dependent increase (EC(50)=8 microM) in 11 beta-HSD2 activity, indicating that binding of NAD(+) to the microsomal 11 beta-HSD2 facilitated the conversion of cortisol to cortisone. Thus, this finding substantiates the previously proposed concept that a compulsorily ordered ternary complex mechanism may operate for 11 beta-HSD2, with NAD(+) binding first, followed by a conformational change allowing cortisol binding with high affinity. Collectively, the present results suggest that cellular mechanisms of SH group modification and intracellular levels of Zn(2+) may play an important role in regulation of placental 11 beta-HSD2 activity.     

Guinea pig 11beta-hydroxysteroid dehydrogenase type 1: primary structure and catalytic properties

The 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) enzyme is responsible for the interconversion of glucocorticoids and their inactive metabolites, and thus modulates the intracellular level of bioactive glucocorticoids. The present study was designed to clone and characterize 11beta-HSD1 in the guinea pig, a laboratory animal known for resistance to glucocorticoids. The cDNA encoding guinea pig 11beta-HSD1 was cloned by a modified 3'-RACE (rapid amplification of cDNA ends) protocol using the hepatic RNA as template. The cloned cDNA encodes a protein of 300 amino acids that shares 71 to 74% sequence identity with other known mammalian 11beta-HSD1 proteins. Sequence comparison analysis revealed that the deduced guinea pig 11beta-HSD1 was longer, by eight amino acids at the C terminus, than those of other mammals. Moreover, one of the two absolutely conserved consensus sites for N-glycosylation was absent. To examine the functional significance of these structural changes, we also characterized 11beta-HSD1 activity in the hepatic microsomes. Although the guinea pig hepatic enzyme was NADP(H)-dependent and reversible, it displayed equal affinity for cortisol and cortisone (apparent K(m) for both substrates was 3 microM). This is in marked contrast to 11beta-HSD1 in other mammals whose affinity for cortisone is approximately 10 times higher than that for cortisol (apparent K(m) of 0.3 vs. 3.0 microM). The apparent lower affinity of the guinea pig enzyme for cortisone would suggest that the intracellular bioformation of cortisol from circulating cortisone may be less efficient in this species. Northern blot analysis and RT-PCR revealed that the mRNA for 11beta-HSD1 was widely expressed in the adult guinea pig but at low amounts. In conclusion, the present study has identified distinct features in the deduced primary structure and catalytic function of 11beta-HSD1 in the guinea pig. Thus, the guinea pig provides a useful model in which the structural determinants of catalytic function of 11beta-HSD1 may be studied.     

Coffee inhibits the reactivation of glucocorticoids by 11beta-hydroxysteroid dehydrogenase type 1: a glucocorticoid connection in the anti-diabetic action of coffee?

Recent epidemiological studies demonstrated a beneficial effect of coffee consumption for the prevention of type 2 diabetes, however, the underlying mechanisms remained unknown. We demonstrate that coffee extract, corresponding to an Italian Espresso, inhibits recombinant and endogenous 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activity. The inhibitory component is heat-stable with considerable polarity. Coffee extract blocked 11beta-HSD1-dependent cortisol formation, prevented the subsequent nuclear translocation of the glucocorticoid receptor and abolished glucocorticoid-induced expression of the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase. We suggest that at least part of the anti-diabetic effects of coffee consumption is due to inhibition of 11beta-HSD1-dependent glucocorticoid reactivation.     

UNC93B1 is essential for TLR11 activation and IL-12-dependent host resistance to Toxoplasma gondii

Toll-like receptor (TLR) activation relies on biochemical recognition of microbial molecules and localization of the TLR within specific cellular compartments. Cell surface TLRs largely recognize bacterial membrane components, and intracellular TLRs are exclusively involved in sensing nucleic acids. Here we show that TLR11, an innate sensor for the Toxoplasma protein profilin, is an intracellular receptor that resides in the endoplasmic reticulum. The 12 membrane-spanning endoplasmic reticulum-resident protein UNC93B1 interacts directly with TLR11 and regulates the activation of dendritic cells in response to Toxoplasma gondii profilin and parasitic infection in vivo. A deficiency in functional UNC93B1 protein abolished TLR11-dependent IL-12 secretion by dendritic cells, attenuated Th1 responses against T. gondii, and dramatically enhanced susceptibility to the parasite. Our results reveal that the association with UNC93B1 and the intracellular localization of TLRs are not unique features of nucleic acid-sensing TLRs but is also essential for TLR11-dependent recognition of T. gondii profilin and for host protection against this parasite.     

Effect of glucocorticoid excess on the cortisol/cortisone ratio

OBJECTIVE: The conversion of cortisol, which binds avidly to the mineralocorticoid receptor, to cortisone, which no longer has mineralocorticoid function, is predominantly catalyzed by the 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD 2). It was the objective of the present study to examine the impact of different forms of glucocorticoid excess on the cortisol/cortisone ratio and to differentiate their role in the genesis of hypertension. DESIGN AND METHODS: Plasma cortisol and cortisone levels were determined in 12 adults with Cushing's disease, 12 adults with hypercortisolism due to an adrenal tumor, and 20 healthy volunteers before and after an intravenous ACTH test, using specific radioimmunoassays after automated Sephadex LH 20 chromatography. RESULTS: The cortisol/cortisone ratios were significantly higher in patients with Cushing's disease (13.9 +/- 1.1), adrenal tumors (11.5 +/- 2.3), and in healthy volunteers after ACTH stimulation (14.1 +/- 2.0) than in untreated controls (6.0 +/- 0.5) (P < 0.001, P < 0.05, and P < 0.001, respectively). Similar differences were seen for cortisol plasma concentrations, whereas cortisone concentrations did not differ among the groups. CONCLUSIONS: Our data suggest that the excessive mineralocorticoid effects in patients with hypercortisolism are inflicted by elevated cortisol/cortisone ratios possibly due to an insufficient conversion of cortisol to cortisone by 11beta-HSD 2. This may provide a possible explanation for the occurrence of hypertension. This effect seems to be independent of the role of ACTH in the mechanism of hypercortisolism.     

The native anti-glucocorticoid paradigm

Circulating 3beta-hydroxysteroids including dehydroepiandrosterone (DHEA) are 7alpha-hydroxylated by the cytochrome P450-7B1 in the liver, skin and brain, which are the target organs of glucocorticoids. Anti-glucocorticoid effects with 7alpha-hydroxy-DHEA were observed in vivo without an interference with glucocorticoid binding to its receptor. In the organs mentioned above, the circulating inactive cortisone was reduced into active cortisol by the 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). We demonstrated that 7alpha-hydroxy-DHEA was also a substrate for this enzyme. Studies of the 11beta-HSD1 action on 7alpha-hydroxy-DHEA showed the reversible production of 7beta-hydroxy-DHEA through an intermediary 7-oxo-DHEA, and the kinetic parameters favored this production over that of active glucocorticoids. Both the production of 7alpha-hydroxysteroids and their interference with the activation of cortisone into cortisol are basic to the concept of native anti-glucocorticoids efficient at their production site. This opens a promising new area for research.