Cortisol metabolism in depressed patients and healthy controls

BACKGROUND

Chronic stress as well as major depressive disorders are associated with hypercortisolemia and impaired hypothalamic-pituitary-adrenocortical axis functioning. The aim of this study was to determine whether in major depression changes in the activity patterns of local modulators of glucocorticoid action might contribute to an increase in cortisol bioavailability and if they change during antidepressant treatment and clinical response.

METHODS

Concentrations of urinary total cortisol (UFF), urinary total cortisone (UFE), tetrahydrocortisone (THE), tetrahydrocortisol (THF) and allo-THF (5alpha-THF) were measured in 10-hour nocturnal urine samples of 19 depressed patients and 15 healthy controls. The activity of 11beta-hydroxysteroid dehydrogenases (11beta-HSD) as well as 5alpha- and 5beta-reductases was assessed by calculating the ratios of glucocorticoid metabolites. Patients were treated for 28 days with either mirtazapine or venlafaxine. Enzyme activity was observed during the course of treatment and compared to healthy controls. Responders to treatment were selected for this analysis.

RESULTS

Depressed patients showed reduced 5alpha-reductase activity manifested as a significantly lower amount of 5alpha-THF (102.8 +/- 167.2 vs. 194.6 +/- 165.8 microg, p = 0.019). The increase in the UFF/UFE ratio (0.73 +/- 0.32 vs. 0.29 +/- 0.13, p < 0.0001) indicates reduced activity of renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). During pharmacological treatment, 5alpha-reductase activity in patients returned to the level of the control group, while the decrease in 11beta-HSD2 activity persisted until day 28.

CONCLUSIONS

Our results show changes in activity of intracellular modulators of steroid action in major depressive disorders, particularly a reduced activity of the intracellular cortisol-deactivating enzymes 5alpha-reductase and 11beta-HSD2. These changes suggest an increase in cortisol bioavailability within tissues.

Reduction in rat phosphatidylethanolamine binding protein-1 (PEBP1) after chronic corticosterone treatment may be paralleled by cognitive impairment: a first study

Chronic stress is associated with hippocampal atrophy and cognitive dysfunction. This study investigates how long-lasting administration of corticosterone as a mimic of experimentally induced stress affects psychometric performance and the expression of the phosphatidylethanolamine binding protein (PEBP1) in the adult hippocampus of one-year-old male rats. Psychometric investigations were conducted in rats before and after corticosterone treatment using a holeboard test system. Rats were randomly attributed to 2 groups (n = 7) for daily subcutaneous injection of either 26.8 mg/kg body weight corticosterone or sesame oil (vehicle control). Treatment was continued for 60 days, followed by cognitive retesting in the holeboard system. For protein analysis, the hippocampal proteome was separated by 2D electrophoresis (2DE) followed by image processing, statistical analysis, protein identification via peptide mass fingerprinting and gel matching and subsequent functional network mapping and molecular pathway analysis. Differential expression of PEBP1 was additionally quantified by Western blot analysis. Results show that chronic corticosterone significantly decreased rat hippocampal PEBP1 expression and induced a working and reference memory dysfunction. From this, we derive the preliminary hypothesis that PEBP1 may be a novel molecular mediator influencing cognitive integrity during chronic corticosterone exposure in rat hippocampus.

Thyroid cysts: a new extra-adrenal site of aldosterone synthase expression and increased aldosterone content

BACKGROUND

The rapid re-accumulation of fluid following aspiration of thyroid cystic lesions suggests that active transport of sodium and water may be involved in volume regulation of these lesions. In this study we address the possibility that aldosterone may take part in this process.

SUBJECTS AND METHODS

Thirty-one patients (29 women and two men), with a mean age of 52.7 +/- 13.2 years (range: 27-77 years) underwent evaluation for thyroid nodules that had a sonographic cystic component. Cystic fluid obtained by FNA biopsy was sent for cytological examination and biochemical measurements. In 10 patients, material was collected for RNA extraction and determination of aldosterone synthase expression by RT-PCR amplification.

RESULTS

All lesions were benign, cystic, colloid nodules. Cyst fluid aldosterone levels as measured by routine radioimmunoassay (RIA) were elevated above the normal plasma levels in all but five patients. Mean aldosterone levels were 27.1 +/- 22.9 ng/dl (SD) (range: 5.9-117.5 ng/dl). In contrast, cyst cortisol values were in the low, low normal serum range (6.2 +/- 2.9 microg/dl, range: 0.2-10.2 microg/dl). Sodium, chloride and potassium levels were 137 +/- 4.7 mEq/l, 98 +/- 5 mEq/l and 4.9 +/- 1.4 mEq/l, respectively. Plasma aldosterone levels were normal in all patients tested. To confirm these results, 12 samples were assayed after extraction and chromatography using a highly specific antibody. Cyst aldosterone levels in this group were elevated above the normal serum range in all but one patient (mean concentration: 24.5 +/- 14.6 ng/dl, range: 8.72-40.1 ng/dl). In this group, 18(OH)B levels were within the normal plasma range (12-55 ng/dl) in all but one patient (34.9 +/- 17 ng/dl). Furthermore, aldosterone synthase mRNA expression was found in aspirates of four of 10 patients.

CONCLUSIONS

The increased aldosterone concentration and the presence of aldosterone synthase expression suggest that aldosterone may be locally produced and secreted in thyroid tissue. The pathophysiological implications of this finding remain to be established.

Effect of temperature on plant elongation and cell wall extensibility

Lockhart equation was derived for explaining plant cell expansion where both cell wall extension and water uptake must occur concomitantly. Its fundamental contribution was to express turgor pressure explicitly in terms of osmosis and wall mechanics. Here we present a new equation in which pressure is determined by temperature. It also accounts for the role of osmosis and consequently the role of water uptake in growing cell. By adopting literature data, we also attempt to report theoretically the close relation between plant elongation and cell wall extensibility. This is accomplished by the modified equation of growth solved for various temperatures in case of two different species. The results enable to interpret empirical data in terms of our model and fully confirm its applicability to the investigation of the problem of plant cell extensibility in function of environmental temperature. Moreover, by separating elastic effects from growth process we specified the characteristic temperature common for both processes which corresponds to the resonance energy of biochemical reactions as well as to the rapid softening of the elastic modes toward the high temperature end where we encountered viscoelastic and/or plastic behavior as dominating. By introducing analytical formulae connected with growth and elastic properties of the cell wall, we conclude with the statement how these both processes contribute quantitatively to the resonance-like shape of the elongation curve. In addition, the tension versus temperature "phase diagram" for a living plant cell is presented.

Anisotropic plant cell elongation due to ortho-gravitropism

In this article we elucidate the well-known biological phenomenon (geotropism) as governed by physical mechanisms, resulting from internal biochemical reactions, in terms of mathematics. Gravitropism causes vertical orientation of plant's axis and in its special cases of positive (root) and negative (stem) geotropism together is called ortho-geotropism. It represents one of the most rapid and visually obvious response of plants to the influence of gravitational field. Seeking for approximate description for this phenomenon we confine to a single cell approach and we begin with the Lockhart equation considering a plant cell as a homogeneous one. In principle, the latter should also account for the existing anisotropies due to mechanical stresses (auxin redistribution). Hence, all global quantities like internal pressure or turgor threshold become direction dependent and consequently acquire tensor representation. Moreover, by involving explicitly time dependence the tensor differential equation becomes a dynamic one. In the context of ortho-geotropism, where gravitational field causes movement of phytohormones and mobile particles following gravity (statolith theory) a basic solution of our tensor equation is found and detailed step by step derivations are presented. By considering only positive (root) geotropism we may, however, extend our solution to the stem bending even though the biological mechanisms differ. Both solutions represent two possible empirical situations which have been probed and verified worldwide ever since.

Anisotropic plant growth due to phototropism

Phototropism--the directional curvature of organs in response to lateral differences in light intensity and/or quality--represents one of the most rapid and visually obvious reaction of plants to changes in their light environment. It is a topic of fundamental interest to understand the mechanics of plants during growth. We propose a generalization of the scalar Lockhart model (1965) to three dimensional deformation, solve the new equation in two particular cases and compare results with empirical data. We believe that carefully designed experiments linked to our model will provide (by determining the active transport coefficient) a new method for qualitative description of auxin redistribution during phototropism. The proposed method supplements very recent investigations concerning specific auxin-influx and -efflux carriers (LAX and PIN proteins).

Kallidin-like peptide mediates the cardioprotective effect of the ACE inhibitor captopril against ischaemic reperfusion injury of rat heart

1. The potential cardioprotective effect of ACE inhibitors has been attributed to the inhibition of bradykinin degradation. Recent data in rats documented a kallidin-like peptide, which mimics the cardioprotective effect of ischaemic preconditioning. This study investigates in isolated Langendorff rat heart the effect of the ACE inhibitor captopril, the role of bradykinin, kallidin-like peptide, and nitric oxide (NO). 2. The bradykinin level in the effluent of the control group was 14.6 pg ml(-1) and was not affected by captopril in the presence or absence of kinin B2-receptor antagonist, HOE140. 3. The kallidin-like peptide levels were approximately six-fold higher (89.8 pg ml(-1)) and increased significantly by treatment with captopril (144 pg ml(-1)), and simultaneous treatment with captopril and HOE140 (197 pg ml(-1)). 4. Following 30 min ischaemia in the control group, the creatine kinase activity increased from 0.4 to 53.4 U l(-1). In the captopril group and in the captopril+L-NAME group, the creatine kinase activity was significantly lower (18.5 and 22.8 U l(-1)). This beneficial effect of captopril was completely abolished by the kinin B2-receptor antagonist, HOE140, as well as by the kallidin antiserum. 5. Perfusion of the hearts with kallidin before the 30 min ischaemia, but not with bradykinin, yielded an approximately 50% reduction in creatine kinase activity after reperfusion. 6. Pretreatment with L-NAME alone and simultaneously with captopril, and with kallidin, respectively, suggests a kinin-independent action of NO before the 30 min ischaemia on coronary flow and a kinin-dependent action after ischaemia. 7. These data show that captopril increases kallidin-like peptide in the effluent. Kallidin-like peptide via kinin B2 receptor seems to be the physiological mediator of cardioprotective actions of captopril against ischaemic reperfusion injury. HOE140 as well as the kallidin antiserum abolished the cardioprotective effects of captopril.

Theoretical search for the growth-temperature relationship in plants

In this article we deal with the definition of a new phenomenological model with physical bases for the response of short-term cell expansion growth to temperature. Although the interest on both the biomechanical bases of elongation growth and on temperature responses has a long lasting development in plant biology and biophysics, yet the question of the mode of actions of temperature is a very relevant and still open one. The purpose of our paper was not to deal with all the complexity of the possible effects of temperature on a growing cell but to concentrate on two more focused questions: i) whether it is possible to specify an optimal temperature for growth responses all along development by defining some phenomenological equations for temperature response, ii) can we learn something from that on the temperature dependence of the cell wall expansion process using a minimal analytical modelling? To answer both questions we introduce (by extending Lockhart approach) the notion of temperature by simple thermodynamical reasoning. Assuming incompressibility of water (by the constant molar density n/V ) we also accounted for the role of osmosis and consequently - the role of water uptake in growing cell. This approach allowed us (by comparing theoretical solutions and experimental results) not only to determine the specific (resonance) temperature (or corresponding absorption energy kBT*) of the optimal growth but also draw conclusions about the cell wall extensibility dependence on temperature and its evolution in time. A straightforward application of our method to determine optimum growth temperature for different plant species in a greenhouse practice (as its simple implication) can also be recommended.

Chronic corticosterone-induced deterioration in rat behaviour is not paralleled by changes in hippocampal NF-kappaB-activation

We investigated whether long-lasting stress induced by chronic glucocorticoid (GC) exposure affects activation of brain NF-kappaB and whether these changes are related to functional deterioration and structural changes in the rat hippocampus. Psychometric investigations were conducted using a holeboard test system in 28 one-year-old male Wistar rats. Thereafter, rats were divided into three groups for daily administration of 10 mg corticosterone (treatment) or sesame oil (placebo = sham control for effects of the vehicle) for 60 days. Additional control rats did not receive any treatment or handling until the end of the experiment. Behavioural and cognitive changes were tested again in the holeboard system. Rat body weights and corticosterone concentrations in plasma, hippocampus and urine were determined and adrenal glands were investigated histopathologically. Hippocampal concentrations of corticosterone, NF-kappaB and I-kappaBalpha were determined using RIA, EMSA and Western blotting techniques, respectively. Structural changes in rat hippocampus were measured using magnetic resonance imaging techniques. High peripheral corticosterone concentrations after chronic treatment led to significant reductions in rat body weight. Significant atrophy of both adrenal glands with marked histological deterioration was detected. Furthermore, an increase in hippocampal corticosterone concentrations was observed after chronic administration. Chronic corticosterone treatment also significantly altered behaviour and working and reference memory capacity without changing hippocampal structure. Daily injections of sesame oil in the placebo group, however, were also sufficient to reduce the pellet-finding time. However, neither in the corticosterone group nor in the placebo group were behavioural changes paralleled by significant changes in brain NF-kappaB activation and I-kappaBalpha expression. Thus, cognitive alterations in rats seen after chronic corticosterone exposure are not paralleled by hippocampal NF-kappaB modulation.

A kallidin-like peptide is a protective cardiac kinin, released by ischaemic preconditioning of rat heart

Bradykinin is thought to play a major role among the endogenous cardioprotective candidates of ischaemic preconditioning (IPC). Little attention has been paid to the fact that in the tissue kallidin (KAL), rather than bradykinin might be the physiological mediator of the kallikrein-kinin system. In order to evaluate the importance of one or the other peptide the release and effect of both kinins has been investigated in isolated rat hearts following IPC. Bradykinin- and a KAL-like peptide were measured in the effluent of the rat isolated Langendorff heart with two different specific radioimmunoassays. The creatine kinase activity in the effluent was judged as degree of cardiac injury caused by ischaemia. During IPC, which consists of three 5 min no-flow and 5 min reperfusion cycles prior to the 30 min ischaemia, the bradykinin level in the effluent did not change significantly (15.4-19.4 pg ml(-1)). In the control group the bradykinin levels were 15.9-16.6 pg ml(-1). During IPC KAL-like peptide (Arg(1)-, instead of Lys(1)-KAL), which has recently been verified by mass spectrometry, displays 5.8-fold higher levels in the effluent and significantly increases in the same time interval from 90.4 to 189 pg ml(-1). After 30 min ischaemia the bradykinin levels in the IPC group were not significantly different to those of the control group (18.7 vs 14.4 pg ml(-1)). The KAL-like peptide levels in the IPC group vs the control group were 105 vs 86.1 pg ml(-1). By the 30 min ischaemia the creatine kinase activity in the IPC group increased from 0.367 to 8.93 U l(-1) (before and 10-30 min after ischaemia). In the control group during the same time period the creatine kinase levels increased from 0.277 to 34.9 U l(-1). The low increase in creatine kinase activity following IPC was taken as equivalent of the cardioprotective action. A KAL antibody or HOE140 (kinin B(2)-receptor antagonist) completely abolished this beneficial effect of IPC (36.6 and 53.0 U l(-1)) when added to the perfusion medium during the reperfusion cycles of IPC prior to the 30 min ischaemia. Our data suggest that in rat hearts KAL-like peptide rather than bradykinin is the physiological compound activated by IPC and acting via the cardiac kinin B(2)-receptor. Thus, endogenously generated KAL-like peptide seems to play a major role in the cardioprotection of IPC.

Rat tissue kallikrein releases a kallidin-like peptide from rat low-molecular-weight kininogen

The kallikrein-kinin system is subdivided into the plasma and tissue-kallikrein-kinin system, with bradykinin (BK) and kallidin (KAL) (Lys(0)-bradykinin) as functional peptides. This occurs in both humans and other mammals. Both peptides are released by plasma and tissue-kallikrein. BK, but not KAL, has been detected in rats until now. One can explain this observation by the structural differences found in the sequence of rat high- and low-molecular kininogen containing an Arg-residue instead of a Lys-residue in front of the N-terminus of the BK sequence. Nevertheless, we were able to measure a kallidin-like peptide (KLP), in rat plasma and urine, using a specific KAL antiserum. In order to confirm our data, we isolated low-molecular-weight kininogen from rat plasma and incubated it with purified rat glandular kallikrein. The generated peptide was retained on a high-pressure liquid chromatography column and displaced by an excess of angiotensin I. The KLP-containing fraction was identified with the KLP radioimmunoassay. A specific ion signal with a mass to charge ratio (m/z) of 1216.73 was detected with matrix-assisted laser desorption/ionization mass spectrometry. As proposed earlier, the structure of this peptide is Arg(1)-KAL, instead of Lys(1)-KAL. The structural similarity between the Lys- and the Arg-residue explains the high crossreactivity (80%) of KLP with the specific KAL antibody. The incubation of KLP with angiotensin-converting enzyme yields two molecules with masses of 913.4 and 729.3 containing the sequence H-Arg-Arg-Pro-Pro-Gly-Phe-Ser-Pro-OH and H-Arg-Arg-Pro-Pro-Gly-Phe-OH. The enzymatic cleavage could be inhibited by captopril. The data suggest that in rats, as in other mammals, the tissue kallikrein-kinin system mediates its physiological effects via a kallidin-like peptide, which is Arg(1)-kallidin (Arg(0)-bradykinin).

A particular phenotype in a girl with aldosterone synthase deficiency

Aldosterone synthase deficiency (ASD) usually presents in infancy as a life-threatening electrolyte imbalance. A 4-wk-old child of unrelated parents was examined for failure to thrive and salt-wasting. Notable laboratory findings were hyperkalemia, high plasma renin, and low-normal aldosterone levels. Urinary metabolite ratios of corticosterone/18-hydroxycorticosterone and 18-hydroxycorticosterone/aldosterone were intermediate between ASD type I and type II. Sequence analysis of CYP11B2, the gene encoding aldosterone synthase (P450c11AS), revealed that the patient was a compound heterozygote carrying a previously described mutation located in exon 4 causing a premature stop codon (E255X) and a further, novel mutation in exon 5 that also causes a premature stop codon (Q272X). The patient's unaffected father was a heterozygous carrier of the E255X mutation, whereas the unaffected mother was a heterozygous carrier of the Q272X mutation. Therefore, the patient's CYP11B2 encodes two truncated forms of aldosterone synthase predicted to be inactive because they lack critical active site residues as well as the heme-binding site. This case of ASD is of particular interest because despite the apparent lack of aldosterone synthase activity, the patient displays low-normal aldosterone levels, thus raising the question of its source.

Endocrine Disorders of Sodium Regulation

Salt and water homoeostasis is tightly regulated by a variety of control mechanisms with the adrenal steroid hormone aldosterone playing a central role. Defects or disturbances in these systems lead to either salt loss, which is life threatening in the neonatal period, or sodium retention causing hypertension. Rapid and accurate diagnosis is required to avoid severe complications. During the last few years molecular genetic advances have been identified as the basic genetic defects for a number of clinical syndromes. This knowledge has considerably increased our understanding of the basic pathways involved in sodium and water homoeostasis and of the pathophysiology of these syndromes, particularly the hypertension. In this review we have summarized the biochemical, physiological and genetic basis for clinical syndromes presenting with salt loss and failure to thrive as well as the rare but important genetic syndromes causing sodium retention and hypertension. Early diagnosis and identification will help to prevent severe complications, but it has to be emphasized that the complicated cascade of aldosterone action is still relatively poorly understood. Further syndromes may exist which once identified will help to better understand the basic physiology of aldosterone action.

No Major Effect of Orciprenaline and Propranolol upon ACTH-Induced Cortisol Secretion

Preclinical research suggests adrenal beta-adrenergic receptors to be involved in the regulation of steroid synthesis. In a group of healthy male volunteers, we compared ACTH-induced cortisol and dehydroepiandrosterone (DHEA) secretion after pre-treatment with orciprenaline, propranolol or placebo. Neither baseline nor ACTH-induced steroid secretion differed between these conditions. Our data do not support the hypothesis that the adrenal beta-receptor plays a major role in steroid secretion in humans.

Association of testosterone and dihydrotestosterone with externalizing behavior in adolescent boys and girls

BACKGROUND

While an association between androgens and different types of aggression has been well documented in male offenders, the influence of androgens on externalizing behavior in adolescents at risk for antisocial behavior has not been investigated so far.

METHODS

Plasma levels of the main androgen metabolites testosterone (T) and 5alpha-dihydrotestosterone (DHT) were measured in N = 87 fourteen-year-old (36 boys, 51 girls) from a prospective longitudinal study of children at risk. Externalizing behavior at age 8, 11 and 14 was assessed using the Achenbach Child Behavior Checklist (CBCL) and Teacher Report Form (TRF).

RESULTS

Significant higher androgen levels (T, DHT) were found in male, but not in female adolescents with elevated scores of externalizing behavior. Moreover, boys with persistent externalizing behavior exhibited the highest levels of plasma androgens.

CONCLUSIONS

There is a link between T, DHT and externalizing behavior in male adolescents at risk for psychopathology. Due to the findings of highest androgen levels in boys with persistent externalizing behavior, a role of androgens in the development of disruptive or later antisocial disorders can be hypothesized.

Cortisol and cortisone in human follicular fluid and serum and the outcome of IVF treatment

BACKGROUND

The glucocorticoid status of ovarian follicular fluid has been linked to oocyte quality. The aim of this study was to examine whether the concentrations of cortisone and cortisol and their calculated ratios in the follicular fluid and serum samples are predictive of IVF outcome.

METHODS

In the prospective study of 387 patients (420 treatment cycles) undergoing IVF treatment the concentrations of cortisone and cortisol were measured with specific assays, and their calculated ratios in the follicular fluid and serum samples obtained after ovarian stimulation and induced ovulation were determined.

RESULTS

In 75 patients, treatment resulted in clinical pregnancy and was associated with significantly lower follicular cortisone (24+/-12 versus 29+/-16 nmol/l, P<0.002) and higher cortisol/cortisone ratio (7.24+/-2.22 versus 6.45+/-2.17 nmol/l, P<0.007). In addition, the ratios of serum cortisone and cortisol to follicular cortisone and cortisol were significantly higher in those women who became pregnant.

CONCLUSIONS

We propose that the follicular fluid glucocorticoid concentration resulting from the conditions in the circulation and the course of the intrafollicular cortisol-cortisone interconversion appear to play a role in the outcome of IVF.

Urinary tetrahydroaldosterone as a screening method for primary aldosteronism: a comparative study

BACKGROUND

The major aldosterone metabolite 3 alpha,5 beta tetrahydroaldosterone reflects up to 45% of the aldosterone secretion. Its 24-h urinary excretion is likely to provide an accurate index of the daily aldosterone production and to be an indicator for primary aldosteronism (PA).

METHODS

In a prospective study, the validity of tetrahydroaldosterone as a screening test for PA was evaluated in comparison to serum potassium, plasma aldosterone, plasma renin activity, plasma aldosterone/renin activity ratio (PARR), as well as 24-h urinary aldosterone-18-glucuronide and free aldosterone. A total of 111 normotensive individuals, 412 PA patients and 1453 essential hypertensive patients, were studied. The effect of blood sampling technique on potassium level was also investigated.

RESULTS

Tetrahydroaldosterone differentiated PA from essential hypertension with a sensitivity of 96% and a specificity of 95%. The sensitivity was 89% for plasma aldosterone, 87% for free aldosterone, 85% for PARR, 71% for aldosterone-18-glucuronide and 51% for renin activity. Specificities varied between 91% and 85%. The combined use of the parameters plasma aldosterone > or =9.0 ng/dL and PARR > or =25 resulted in a sensitivity of 82% and specificity of 95%. Forearm exercise proved to be a source of erroneous elevations of potassium sufficient to obscure the suspicion of PA.

CONCLUSION

The data suggest that tetrahydroaldosterone is the most reliable screening test for PA. Tetrahydroaldosterone determination in combination with aldosterone-18-glucuronide and free aldosterone increases diagnostic specificity for PA. Potassium, renin, plasma aldosterone, and basal PARR are inadequate screening procedures because they are subject to high rates of false-positive and false-negative results.

[Role of androgens in externalizing behavior problems in adolescents]

OBJECTIVE

While an association between androgens and different types of aggression has been well documented in male offenders, the influence of androgens on externalizing behavior in adolescents at risk for antisocial behavior has not been investigated so far.

METHODS

Plasma levels of the main androgen metabolites testosterone (T) and 5a-dihydrotestosterone (DHT) were measured in N = 119 14-year-olds (51 boys, 68 girls) from a prospective longitudinal study of children at risk. The Achenbach Child Behavior Checklist (CBCL) and the Youth Self Report Form (YSR) were used to assess externalizing behavior at age 14.

RESULTS

The CBCL revealed significant positive correlations between DHT levels and the subscales "externalizing problems" and the problem scales "aggressive behavior" and "delinquent behavior" in male adolescents. Only the YSR subscale "delinquent behavior" exhibited a marginally significant association with DHT. Neither scale showed any significant correlations between androgen levels and externalizing behavior in female adolescents.

CONCLUSIONS

Earlier findings of androgen effects on aggressive and antisocial behavior in male offenders were confirmed for male adolescents from a general population sample. The results stress the importance of the androgen metabolite DHT.

Regulatory effects of salt diet on renal renin-angiotensin-aldosterone, and kallikrein-kinin systems

The interaction of the renin-angiotensin-aldosterone system (RAAS) and the kallikrein-kinin system (KKS) was investigated in rats fed on a low, normal, and high-salt diet for 2 weeks. At the beginning of the second week, either a B2-receptor antagonist (icatibant), or an AT1-receptor antagonist (losartan), or an aldosterone receptor antagonist (spironolactone) was applied via osmotic pump delivering a constant amount of drug for 7 days. The urinary bradykinin (BK) levels corresponded with increasing NaCl diet and the activity of urinary kallikrein. However, in agreement with other investigators we found a down-regulation of the renal kallikrein gene expression in response to an increasing NaCl diet. Renal kinins are able to stimulate the renal kallikrein expression as well as the renal excretion of active kallikrein via the B2-receptor. The release of renal kallikrein is also mediated by angiotensin II (AngII). After high-salt diet the blood pressure was significantly increased. Losartan and spironolactone were not effective in reducing this increase, as AngII and aldosterone should be low during high-salt diet. However, low-salt diet also yielded an increase in blood pressure, which, however, could be abolished following losartan infusion. The data suggest that the expression of renal kallikrein mRNA is mainly regulated by dietary salt intake. However, kinins are able to stimulate the kallikrein gene expression, as well as the renal kallikrein release. Angll mediates only a stimulatory effect on the urinary kallikrein release. In contrast to the general belief, our data support the opinion that low-salt diet is able to mediate an increase in blood pressure, as the RAAS is stimulated in response to a marked salt deficiency.

Brain-derived-neurotrophic-factor (BDNF) stress response in rats bred for learned helplessness

Stress-induced elevation of glucocorticoids is accompanied by structural changes and neuronal damage in certain brain areas. This includes reduced expression of brain-derived neurotrophic factor (BDNF) in the hippocampus which can be prevented by chronic electroconvulsive seizures and antidepressant drug treatment. In the last years we have bred two strains of rats, one which reacts with congenital helplessness to stress (cLH), and one which congenitally does not acquire helplessness when stressed (cNLH). After being selectively bred for more than 40 generations these strains have lost their behavioural plasticity including their sensitivity to antidepressant treatment. We show here that in cLH rats, acute immobilization stress does not induce a reduction of BDNF expression in the hippocampus which is observed in Sprague--Dawley and cNLH rats. All animals tested exhibited elevated corticosterone levels when stressed, an indication, that in cLH rats regulation of BDNF expression in the hippocampal formation is uncoupled from corticosterone increase induced through stress. This may explain the lack of adaptive responses in this strain.

Testosterone, androstenedione and dihydrotestosterone concentrations are elevated in female patients with major depression

Hyperactivity of the HPA-system in major depression is reflected by an increased secretion of adrenal hormones especially cortisol and dehydroepiandrosterone (DHEA). In women for whom androgenicity is associated with cardiovascular disorders the dominant source of androstenedione and testosterone secretion are the adrenal glands. To date, there is only sparse information about the regulation of androstenedione, testosterone and dihydrotestosterone (DHT) concentrations in women with severe major depression.Therefore, 11 pre- and postmenopausal, severely depressed, hypercortisolemic women (Hamilton Depression Scale, 31.3+/-5.9; age, 28-77 yrs; mean, 48. 1+/-18.1 yrs) and 11 age-matched healthy female controls (age, 24-81 yrs; mean, 47.9+/-21.5 yrs) underwent a 24 hour (h) blood sampling starting at 0800 h with 30-minute sampling intervals. By applying multivariate analysis of covariance with age as covariate, androstenedione, testosterone and DHT plasma levels at 0900 h show a trend for elevated concentrations in depressed women compared to controls (F(1,19)=2.7; P=0.057). Univariate F tests reveal a significant difference between the groups for androstenedione (4. 19+/-1.571 vs 2.584+/-1.257 nmol/l; P<0.05) testosterone (1.110+/-0. 278 vs 0.833+/-0.347 nmol/l; P<0.05) and DHT (0.656+/-0.207 vs 0. 483+/-0.242 nmol/l; P<0.05). Mean ACTH (16.4+/-10.4 vs 10.4+/-2.4 pmol/l; P=0.89), LH (13.5+/-11.8 vs 8.9+/-9.2 IU/l; P=0.12), FSH (35. 2+/-33.1 vs 31.3+/-35.7 IU/l; P=0.67) and estradiol (135.4+/-157.4 vs 82.2+/-85.1 pmol/l; P=0.20) plasma levels did not differ between patients and controls. Further, there was a trend towards an age related decline in testosterone secretion in healthy controls (r=-0. 24; P=0.08) which did not occur in depressed patients (r=0.17; P=0. 96), while the calculated ratio of DHEA to testosterone was similar in both groups (0.2+/-0.14 vs 0.13+/-0.7; P=0.21, unpaired t-test). In conclusion, androstenedione, testosterone and DHT concentrations all were increased in hypercortisolemic women with severe major depression. These findings are best explained as a consequence of an overstimulation of the adrenal glands through pituitary and hypothalamic sites of the HPA-system.

Increased diurnal plasma concentrations of cortisone in depressed patients

The enzyme 11-beta-hydroxysteroid dehydrogenase (11-beta-HSD) regulates glucocorticoid activity by converting cortisol into cortisone and vice versa. Frequent signs of major depression are elevated concentrations of circulating cortisol and ACTH. However, no information is available about the activity of 11-beta-HSD in this disorder. Therefore, we compared diurnal plasma concentrations of cortisol and cortisone and their ratios, reflecting 11-beta-HSD activity, in 25 severely depressed patients (Hamilton Depression Scale, 29 +/- 6; 14 men, 11 women, age 22-77 yr; mean, 47 +/- 16) and 30 control persons (20 men, 10 women age 23-85 yr; mean, 51 +/- 19). Cortisol and cortisone were measured at 0900 h, 1100 h, 1300 h, 2000 h, 2200 h, 0100 h, 0300 h, and 0700 h with specific RIAs after extraction. Both cortisol and cortisone concentrations were significantly increased in patients compared with controls (cortisol, 251.7 +/- 113.1 vs. 160 +/- 96.6 nmol/L; cortisone, 32.8 +/- 10.9 vs. 21.9 +/- 10.9 nmol/L). The calculated ratios of cortisol to cortisone were similar in controls and patients. Similar to cortisol, the circadian variation of cortisone was flattened in patients with the ratio of maximal cortisone to minimal cortisone being 1.9-fold higher in controls than in patients. There was no gender-specific difference in cortisone values neither in patients nor in controls. We conclude that in major depression increased cortisol is not due, at least partly, to an altered 11-beta-HSD activity or to a decrease in cortisone.

Effect of sodium restriction on urinary excretion of cortisol and its metabolites in humans

The adrenal gland is involved in the control of urinary sodium excretion mainly via the secretion of the mineralocorticoid aldosterone. Although under certain conditions glucocorticoid seem to be also involved in the regulation of sodium homeostasis, there are contradictory reports on the relationship between cortisol secretion and sodium intake. Given recent findings linking regulation of physiological activity of steroids to the activity of specific enzymatic pathways, we have examined changes in urinary excretion of cortisol and its metabolites in eight healthy volunteers on a low sodium diet. Urinary steroids were measured with specific radioimmunoassays after extraction and chromatography (F and E) or after dilution (THF and THE). Excretion of cortisol (124 +/-41 nmol/day) was significantly lower on Day 2 (86 +/- 27 nmol/day, p < 0.01) and Day 7 (85 +/- 25 nmol/day, p < 0.01) of sodium restriction. On the same samples calculated ratios of THF/F (55 +/- 15; 61 +/- 22; 68 +/- 21) and E/F (2.5 +/- 0.6; 2.8 +/- 1.4; 3.0 +/- 1.3) reflecting the activity of 5 beta-reductase and 11 beta-hydroxysteroid dehydrogenase, respectively, showed significant increases in the former on both Days 2 and 7 and for the latter only on Day 7. This study supports the notion that sodium restriction decreases urinary cortisol excretion and provides evidence that increased activity of 5 beta-reductase and lowered metabolism by 11 beta-HSD are presumably the mechanisms of this decrease.

Further studies on the mechanism of the mineralocorticoid action of licorice in humans

The pathogenesis of pseudohyperaldosteronism from licorice has been evaluated in 6 male volunteers taking daily 7 g of a commercial preparation of licorice for 7 days, corresponding to an intake of 500 mg/day of glycyrrhizic acid. Pseudohyperaldosteronism was evident during the treatment (increase of body weight, suppression of plasma renin activity and plasma aldosterone, reduction of serum potassium). The ratio (tetrahydrocortisol + allo tetrahydrocortisol)/tetrahydrocortisone in urine increased in 5 cases after 3 days of treatment, without an increase of plasma mineralocorticoid activity (PMA). In the 6th case the urinary ratio was unchanged and PMA increased from the pretreatment value. After 7 days of therapy the ratio remained high and PMA was not measurable in 3 cases, while in the other 3 cases the ratio returned to pretreatment and PMA was higher than pretreatment value. We conclude that the pseudohyperaldosteronism from licorice is initially related to decreased activity of 11 beta-hydroxysteroid-dehydrogenase and afterwards also a direct effect of licorice derivatives on mineralocorticoid receptors becomes evident in some cases. In other cases however the effect on the enzyme is prevailing probably due to individual factors.

A new subset of mineralocorticoid hypertension with excess of 21-deoxyaldosterone and Kelly's-M1 steroid: clinical and morphological findings

Ten cases of adrenal adenomas, one case with unilateral adrenal hyperplasia, and another case with apparent bilateral are reported, in whom an alternative pathway of aldosterone via 21-deoxyaldosterone is operative. They all manifested hypertension, low renin activity, low normal potassium values, as well as high urinary excretion rates of 21-deoxyaldosterone and its related metabolite Kelly's-M1 steroid. In all cases, urinary aldosterone metabolites (aldosterone-18-glucuronide and tetrahydroaldosterone) and aldosterone precursor 18-hydroxycorticosterone levels were normal. Hence, the adrenal lesions give rise to hyper-21-deoxyaldosteronism. 21-Deoxyaldosterone is a weak mineralocorticoid, and its elevated production in the presence of normal aldosterone can induce a pathological state of hypermineralocorticoidism. Adrenalectomy resulted in normalization of hypertension in six of eight and amelioration in two of eight cases. Six of seven adenoma cases examined as well as the case of unilateral adrenal hyperplasia were sensitive to ACTH. One of the seven adenomas and, as expected, the case with apparent bilateral hyperplasia were angiotensin responsive. Histologically and electron microscopically, the operated adenomas consisted predominantly of clear cells, characterized by mitochondria with tubulo-vesicular internal structure similar to those of the zona fasciculata (in contrast, our classical Conn's adenoma with normal 21-deoxyaldosterone excretion exhibited a more heterogenous histological appearance and were, in terms of ultrastructure, more similar to cells of the zona glomerulosa). Ultrastructurally and immunocytochemically, the clear cells of 21-deoxyaldosterone adenomas showed features of both the zona glomerulosa and the zona fasciculata and are, hence, considered to be hybrid cells. We conclude that the determination of 21-deoxyaldosterone and Kelly's-M1 should be considered in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma has been detected with an imaging procedure.

Divergence between genotype and phenotype in relatives of patients with the intron 2 mutation of steroid-21-hydroxylase

We studied 95 patients and their relatives with the classical salt wasting (SW) and simple virilizing (SV) form of CAH. SSCP/heteroduplex analysis allowed fast and efficient screening for the most common 21-hydroxylase mutations (e.g. deletions, splice site mutation in intron 2 (bp 656), Ile172Asn mutation in exon 4) and determination of the relative intensities of CYP21A and CYP21B genes. The splice site mutation in intron 2 was found as the most frequent cause of 21-hydroxylase deficiency (35% of our patients). There is a strong genetic association between the mutation in intron 2 and the SW form of CAH. On the other hand, about 20% of our patients with the intron 2 mutation have the SV phenotype. Interestingly, homozygous splice site mutations in intron 2 were also detected in some parents or other relatives with no phenotypic changes typical for CAH (clinical evaluation, steroid hormone levels). In those patients with SV-CAH and especially in the relatives with the homozygous intron 2 mutation and an unaffected phenotype, the splice site mutation could be "leaky". mRNA-splicing in the adrenal cortex should result in a high degree of normal mRNA species. This is in contrast to in vitro expression studies of CYP21B genes containing the intron 2 mutation, performed by other groups. However, the results of in vitro expression studies are not always reflecting the in vivo conditions in the adrenal cortex. This situation is in good agreement with the variable degree of normal spliced mRNA and different phenotypic severity in intron mutations found in thalassemia.

Increased aldosterone-18-glucuronide/tetrahydroaldosterone ratios in pregnancy

In the present study the aldosterone-18-glucuronide and tetrahydroaldosterone values in 24 hour urine collections of healthy nonpregnant women, women with normal pregnancies and women with pregnancy induced hypertension (PIH) were compared. In pregnancy an elevated excretion of both aldosterone metabolites was found. The Q-ratio (aldosterone-18-glucuronide/tetrahydro-aldosterone+aldosterone-18-glu cur onide) was also increased compared to healthy nonpregnant women. The elevated Q-ratios point out to increased formation of aldosterone-18-glucuronide. This predominantly renal metabolite may reflect greater availability of aldosterone molecules for interaction with mineralocorticoid receptor in the kidney.

Role of 21-deoxyaldosterone in human hypertension

21-Deoxyaldosterone has been postulated to be a precursor of aldosterone in an alternative biosynthesis pathway and Kelly's-M1 is considered to be its metabolite. In healthy volunteers, the excretion rate of 21-deoxyaldosterone and of Kelly's-M1 are significantly lower than the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone and than the aldosterone precursor 18-OH-corticosterone. Essential hypertension patients (with low and normal renin) excrete comparable values of 21-deoxyaldosterone and Kelly's-M1 as normotensives. In 66% of aldosterone-producing adenoma cases (APA) and in 60% of idiopathic hyperaldosteronism (IHA) patients, significantly raised values of 21-deoxyaldosterone and Kelly's-M1 were found. The patients with the high excretion rates of both steroids showed only moderately increased values of the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone, as well as of the aldosterone precursor 18-OH-corticosterone. In contrast, the latter mentioned steroids were excreted in higher amounts in those patients with normal excretion of 21-deoxyaldosterone and Kelly's-M1. Hence, it is suggested that aldosterone is produced alternatively either via 18-OH-corticosterone alone or additionally via 21-deoxyaldosterone. Furthermore, in three cases of "incidentally" discovered adrenal adenomas, 21-deoxyaldosterone and Kelly's-M1 were the only elevated steroids. After adrenalectomy, excretion of 21-deoxyaldosterone and of Kelly's-M1 and blood pressure returned to normal, which proves that these steroids play a role in blood pressure regulation. In essential hypertension, ACTH infusion induced a significant increase of 21-deoxyaldosterone and Kelly's-M1. However, the increase after angiotensin II was 3- to 6-fold higher than after ACTH. IHA patients proved to be more responsive to angiotensin II; and, in contrast, APA cases proved to be more sensitive to ACTH. The data suggest that beside the main route of aldosterone biosynthesis via 11-deoxycorticosterone, corticosterone and 18-OH-corticosterone an alternative pathway exists via 21-deoxyaldosterone in healthy and in hypertensive patients. There are similarities between the regulation of 21-deoxyaldosterone and the regulation of aldosterone. The determination of 21-deoxyaldosterone and its possible metabolite Kelly's-M1 might be appropriate in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma is discovered.

[Variability of corticosterone methyl oxidase (type II) deficiency. Presentation of three case reports]

We report on three cases of Corticosterone Methyl Oxidase Typ II deficiency in two siblings and one boy. All three children were presented with typical symptoms of a saltlosing syndrome (vomiting, poor drinking, weight loss, hypotonia). Hyponatremia and hyperkalemia, low plasma aldosterone concentrations when related to high plasma-renin-activities suggested deficiency in the final steps of aldosterone biosynthesis. Variable degrees of enzyme deficiency and no relation of biochemical findings to the clinical symptoms were observed. Clinical symptoms became less severe with age. Diagnosis of CMO II-deficiency was established by an abnormal high ratio of 18-hydroxycorticosterone to aldosterone, by measurement of their precursors and metabolites in plasma and urine. In one sibling negative values may have been caused by suppression of the renin-angiotensin-system due to high sodium replacement therapy.

Hypertension in pregnancy

Pregnancy-induced hypertension (PIH) is a frequent cause of maternal and neonatal morbidity and mortality. In the present study we focused on the pathophysiology of PIH, mainly on the role of mineralocorticoids, reversed blood pressure patterns, and the resulting necessity of continuous monitoring of the preeclamptic mother. Problems of antihypertensive therapy are discussed and the first results of a pilot study with Urapidil are presented. To examine the role of mineralocorticoids in the pathophysiology of PIH, we studied plasma aldosterone and 18-hydroxy-corticosterone (18-OH-B) levels in 25 women with PIH and in 25 healthy pregnant women. Furthermore, we evaluated the mineralocorticoid receptor (MR) count in mononuclear leukocytes in the 2 groups. The MR-count was significantly decreased in the PIH-group. The values of plasma aldosterone and 18-OH-B were also low. These results cannot be explained by receptor down-regulation due to higher level of mineralocorticoids of the zona glomerulosa. Perhaps deoxycorticosterone or a hitherto unknown mineralocorticoid is responsible for the hypertension and altered MR-status. The first results of continuous blood pressure measurements with a noninvasive, real-time blood pressure monitor (Finapres) are presented. The comparison of the obtained values with intraarterial measurements demonstrates a good correlation between the two methods. We also report on the first experiences with Urapidil in the treatment of hypertension in severe preeclampsia. The data show that hypertension in preeclamptic women can be treated by Urapidil without side effects or reflex-tachycardia. Further studies will have to prove if Urapidil is suited for prepartal treatment of PIH as well.

Effect of sodium restriction on urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone, newly identified mineralocorticoids in man

19-Noraldosterone, which was recently shown to be synthesized and produced in the human adrenal gland, possesses potent mineralocorticoid activity. 18,19-Dihydroxycorticosterone [18,19-(OH)2B], a possible precursor of 19-noraldosterone, has also been identified in human urine. To elucidate the regulatory mechanism for these newly described steroids, we studied the effect of sodium restriction on the urinary excretion of 19-noraldosterone and 18,19-(OH)2B in six normal subjects. 18,19-(OH)2B and 19-noraldosterone were measured by specific RIAs after purification of the urine extract by high performance liquid chromatography. The 24-h urinary excretion of 19-noraldosterone and 18,19-(OH)2B during the control period were 107 +/- 40 (+/- SE) pmol/day and 5.6 +/- 0.8 nmol/day, respectively. After sodium restriction, the values increased approximately 2-fold (P less than 0.05), to 259 +/- 76 pmol/day and 15.6 +/- 4.5 nmol/day, respectively. Virtually identical responses were seen for aldosterone (from 21 +/- 6.0 to 38 +/- 10 nmol/day), 18-hydroxycorticosterone (from 9.9 +/- 1.1 to 21 +/- 2.8 nmol/day), and 18-hydroxycortisol (from 377 +/- 93 to 554 +/- 129 nmol/day). These observations suggest that 19-noraldosterone and 18,19-(OH)2B are partly under the control of the renin-angiotensin system in normal subjects.

Urinary 18,19-dihydroxycorticosterone and 18-hydroxy-19-norcorticosterone excretion in patients with primary and secondary aldosteronism

18,19-Dihydroxycorticosterone (18,19(OH)2-B) and 18-hydroxy-19-norcorticosterone (18-OH-19-nor-B) measurements were carried out on the urine of patients with primary aldosteronism (PA), essential hypertension (EHT), and liver cirrhosis with (LC, SA (+)) and without (LC, SA (-)) aldosteronism. The separation of these steroids was performed by extraction and high-performance liquid chromatography followed by radioimmunoassay (RIA) with specific antibodies prepared in our laboratory. 18,19(OH)2-B excretion was elevated in patients with PA (24 +/- 5.9 [+/- SE] micrograms/24 hr; n = 15) and LC, SA (+) (83 +/- 9.4 micrograms/24 hr; n = 8). Values in LC, SA (-) (3.1 +/- 1.2 micrograms/24 hr; n = 8) and in EHT (3.7 +/- 0.4 micrograms/24 hr; n = 42) were found to be similar to those in normal subjects (5.5 +/- 0.9 micrograms/24 hr; n = 30). The values of urinary 18-OH-19-nor-B in PA and LC, SA (+) were higher than in LC, SA (-) EHT and normal subjects (P less than 0.05). Values in the latter three groups, as compared with each other, did not show significant alterations. Nothing is known about the biologic relevance of 18,19(OH)2-B and very little about that of 18-OH-19-nor-B, but the latter steroid seems to potentiate experimental renal hypertension. One can speculate about possible roles of both steroids as precursors of other steroids, e.g., the biologically potent mineralocorticoid 19-noraldosterone. The data obtained suggest that it is not relevant to measure the urinary levels of either steroid in these clinical syndromes.

Interference of C17-spirosteroids with late steps of aldosterone biosynthesis. Structure-activity studies

Structure-activity relationships concerning the steroidal skeleton as well as the C21,17-ring systems could be established while investigating the inhibitory effects of 27 different C17-spirosteroids on aldosterone synthesis in vitro. 18-hydroxylation appeared to be the crucial point of interference with all active compounds, whereas impairment of 11 beta- and 21-hydroxylase, respectively, was of minor importance, i.e. occurring to a smaller degree and only with a few test substances. Inhibition of 18-hydroxylation was associated with the following structural features: C21,17-spiro-gamma-lactone ring with 17 beta-O-atom; 3-oxo group in combination with delta 4,5-6,7-diene structure or, alternately, combination of 3-oxo group or even a bulky 3-O-function, if it protrudes out of ring plane in beta-position, and 7a-thioalkyl- or thioacyl- or thiol groups; combination of 17-spiro-gamma-lactone and a 3-O-function may result in an active compound even without 7a-substituents, provided there are no additional groups fixed on the steroidal skeleton. Elimination of an angular methyl group (----nor-compound), however, is acceptable. On the other hand, inhibitory potency is abolished or diminished by the following structural features: 7a-groups containing oxidized sulphur (e.g. suphoxy- or sulphonyl groups); bulky 3-substituents fixed in the ring plane via double bond; 18-alkyl groups; 6 beta-substituents; 2-substituents in absence of 7a-groups, depending on their configuration (e.g. cycle or chain); introduction of a heteroatom at C21, i.e. instead of the carbonyl-C-atom. Mespirenone (CAS 87952-98-5), the test substance of central concern, possesses favourable structural features finding its expression in a correspondingly enhanced inhibitory action.

Inhibitory effects of the novel anti-aldosterone compound mespirenone on adrenocortical steroidogenesis in vitro

Mespirenone (CAS 87952-98-5), the delta 1,2-15 beta, 16 beta-methylene derivative of spironolactone, proved to be a potent and quite specific inhibitor of adrenocortical mineralocorticoid synthesis in vitro. At 10(-4) mol/l concentrations, the production of aldosterone as well as its possible precursor 18-OH-corticosterone was inhibited more than 40% (p less than 0.01), whereas corticosterone was elevated highly significantly. This points to a clearcut blockade of 18-hydroxylase on the main pathway of aldosterone synthesis by mespirenone. Decrease of 18-OH-progesterone- and increase of 21-deoxyaldosterone secretion suggests two additional points of interference on an alternate pathway of aldosterone biosynthesis, i.e. 18- and 21-hydroxylation, respectively. Thus, mespirenone causes an effective all-around inhibition of mineralocorticoid synthesis in rat adrenals. On the contrary, androstendione levels remained virtually unchanged indicating that mespirenone exerts no inhibitory effects on androgen synthesis. In conclusion, mespirenone, due to inhibition of mineralocorticoid synthesis in addition to antagonistic effects on the receptor level, is a candidate for the development of a new, potent and specific anti-aldosterone drug.

Synthesis of 19-nor-aldosterone, 18-hydroxy-19-nor-corticosterone and 18,19-dihydroxycorticosterone in the human aldosterone-producing adenoma

The recently synthesized 18-C-steroid derivative, 19-nor-aldosterone(19-nor- aldo) and 18-hydroxy-19-nor-corticosterone(18-OH-19-nor-corticosterone) possess mineralocoroticoid and hypertensinogenic activity. They and an additional newly synthesized steriod, 18,19-dihydroxycorticosterone[18,19(OH)2-corticosterone], may play a role in the etiology and pathogenesis of disorders thought to be caused by steroids with mineralocorticoid and hypertensionogenic properties. In this study we provide evidence that 19-nor-aldo, 18-OH-19-nor-corticosterone and 18,19(OH)2-corticosterone are produced in vitro by aldosterone-producing adrenal adenomas and adenomas and adenoma of Cushing's syndrome. "silent" adrenal adenomas and the adjacent adrenal tissue. Measurable amounts of these steroids were found in the incubation fluids of adrenal tissues using specific RIAs performed after a sequence of HPLC systems. The rates of production of the three steroids were high in the aldosterone-producing adrenal adenomas and in adrenal hyperplasia compared with in either Cushing's adenoma or "silent" adenoma.

Synthesis of 4,19-disubstituted derivatives of DOC. Radioreceptor assay of some corticosteroid derivatives in human mononuclear leukocytes

Several new 4,19-substituted steroids and previously synthesized corticosteroids were assayed for affinity to type 1 receptors in human mononuclear leukocytes. 11 beta,19-epoxy-4,21-dihydroxypregn-4-ene-3,20-dione (2) was hydrogenated with Pd-C to yield a mixture of all four dihydro derivatives 5, accompanied by 4,21-diacetoxy-11 beta,19-epoxy-3-hydroxypregnan-20-one (6) and 21-acetoxy-11 beta,19-epoxy-4-hydroxypregnane-3,20-dione (7). With hot acetic + p-toluenesulfonic acid 5 underwent rearrangement to 21-acetoxy-11 beta,19-epoxypregn-5-ene-4,20-dione (8) Pd-C hydrogenation of 3,21-diacetoxy-5 beta,19-cyclopregna-2,9(11)-diene-4,20-dione (10) gave 3,21-diacetoxy-5 beta,19-cyclopregn-5-ene-4,20-dione (11) and the 9,11-dihydro derivative of the latter. Treatment of 10 with warm HCl furnished 19-chloro-4,21-dihydroxypregna-4,9(11)-diene-3,20-dione (13). Pd-C hydrogenation of its diacetate 14 afforded the 4,5-dihydro derivative 18, 19-chloro-21-acetoxypregn-9(11)-en-20-one (15), its 4-acetoxy derivative 16 and the 3,4-diacetoxy derivative 17. When tested in a radioreceptor assay in human mononuclear leukocytes the synthesized compounds showed only low relative binding affinities (RBA) to type 1 receptor, the highest being 0.72% for 13 (aldosterone = 100%). For comparison, other RBA in this system were: 19-noraldosterone, 20%; 18-deoxyaldosterone, 5.8%; 18-deoxy-19-noraldosterone, 4.7%; 18,21-anhydroaldosterone, 0.37%; 17-isoaldosterone, 7.6% and apoaldosterone, 4.3%

Production of 21-deoxyaldosterone by rat adrenal tissue in vitro: evidence for an alternative biosynthetic pathway of aldosterone

Quartered rat adrenal glands transformed labelled 21-deoxyaldosterone into aldosterone in vitro. 21-deoxyaldosterone was released from the quartered rat adrenals in vitro in amounts 10 times lower than those of aldosterone and 18-hydroxycorticosterone. The production of all three steroids was qualitatively dependent on the same regulatory elements (electrolytes, ACTH, exogenous precursors, zonal specificity). However, quantitative differences could be observed. The results support a role for 21-deoxyaldosterone as a facultative precursor of aldosterone and indicate that the regulation of its production shows similarities to that of aldosterone.

18,21-Anhydroaldosterone and derivatives

18,21-Anhydroaldosterone 8, 18,21-anhydro-19-noraldosterone 9, and 3 alpha, 5 beta-tetrahydro-18,21-anhydro-19-noraldosterone 13, which may be present in acid-processed urine, were prepared by cleaving their 20-ketal derivatives 2, 3, and 12 with hot mineral acid. Compounds 8 and 9 were also made by direct dehydration of aldosterone 5 and 19-noraldosterone 10 in good yield. The reverse ring opening of 8 to 5 could be carried out in moderate yield with an acetic acid-acetic anhydride-perchloric acid mixture, while an analogous ring opening of 9 gave only a poor yield of 10.

Identification and regulation of 1,25-dihydroxyvitamin D3 receptor activity and biosynthesis of 1,25-dihydroxyvitamin D3. Studies in cultured bovine aortic endothelial cells and human dermal capillaries

Because 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been shown to play roles in both proliferation and differentiation of novel target cells, the potential expression of 1,25(OH)2D3 receptor (VDR) activity was investigated in cultured bovine aortic endothelial cells (BAEC). Receptor binding assays performed on nuclear extracts of BAEC revealed a single class of specific, high-affinity VDR that displayed a 4.5-fold increase in maximal ligand binding (Nmax) in rapidly proliferating BAEC compared with confluent, density-arrested cells. When confluent BAEC were incubated with activators of protein kinase C (PKC), Nmax increased 2.5-fold within 6-24 h and this upregulation was prevented by sphingosine, an inhibitor of PKC, as well as by actinomycin D or cycloheximide. Immunohistochemical visualization using a specific MAb disclosed nuclear localized VDR in venular and capillary endothelial cells of human skin biopsies, documenting the expression of VDR, in vivo, and validating the BAEC model. Finally, additional experiments indicated that BAEC formed the 1,25(OH)2D3 hormonal metabolite from 25(OH)D3 substrate, in vitro, and growth curves of BAEC maintained in the presence of 10(-8) M 1,25(OH)2D3 showed a 36% decrease in saturation density. These data provide evidence for the presence of a vitamin D microendocrine system in endothelial cells, consisting of the VDR and a 1 alpha-hydroxylase enzyme capable of producing 1,25(OH)2D3. That both components of this system are coordinately regulated, and that BAEC respond to the 1,25(OH)2D3 hormone by modulating growth kinetics, suggests the existence of a vitamin D autocrine loop in endothelium that may play a role in the development and/or functions of this pathophysiologically significant cell population.

The pathogenesis of pseudohyperaldosteronism from carbenoxolone

Carbenoxolone is a derivative of glycyrrhetinic acid used for the treatment of peptic ulcer and gastritis, with salt and water retention a very common side-effect. To investigate this drug-induced pseudohyperaldosteronism we have studied 6 male volunteers before, during and after treatment with carbenoxolone for 7 days. Serum, urinary and sweat electrolytes values were consistent with a mineralocorticoid-like effect of drug administration. PRA was suppressed, and plasma cortisol and aldosterone progressively decreased over treatment. We have also determined by radioreceptor assay the plasma levels of factors which bind to mineralocorticoid receptors in rat kidney cytosol. The levels of these factors were decreased significantly at day 3 of treatment, suggesting a local renal effect of carbenoxolone to amplify endogenous steroid action. At day 7 the radioreceptor assay values were still decreased but significantly higher than at day 3, suggesting in addition a direct mineralocorticoid effect of the drug. We conclude that the drug is initially effective by amplifying the effect of endogenous steroids, and then when the plasma concentrations of the drug or its metabolites reach a higher plasma concentration, there may also be in addition a direct mineralocorticoid-like effect.

Primary glucocorticoid receptor defect with likely familial involvement

A 29-year-old woman with moderately elevated blood pressure and signs of hyperandrogenism (hirsutism and acne) but without typical Cushing's syndrome symptoms has been followed for almost 6 years. Steroid and glucocorticoid receptor studies indicated a primary glucocorticoid receptor defect. Elevated androgen values were of special interest. Clinical manifestation of hyperandrogenism seemed not to be proportional to the biochemical findings. Therefore, the possibility of a partial androgen receptor defect should also be considered.

Comparative dose-effect studies with four C-17-spirosteroidal mineralocorticoid synthesis inhibitors

Interference of three spirolactones and a spiro-oxazolidine with mineralocorticoid biosynthesis in the concentration range of 10(-4)-10(-10) M has been studied in isolated dispersed z. glomerulosa cells. Inhibitory effects on several enzyme activities involved in the late steps of aldosterone synthesis have been determined. Different patterns of enzyme inhibition could be observed for each inhibitor. The points of interference were mostly related to cytochrome P450-C11-activities (i.e. 11 beta-/18-hydroxylation and 18-OH-oxidation).

Urinary excretion of aldosterone metabolite Kelly-M1 in patients with adrenal dysfunction

Using tetrahydroaldosterone antibody a radioimmunoassay was developed to measure substance Kelly-M1 (K-M1) in human urine. The normal values were lower than observed by Kelly et al. who discovered the catabolite after giving large doses of exogenous aldosterone. While in essential hypertension the excretion of K-M1 was predominantly within the normal range, elevated values were found in most cases of 21-hydroxylase deficiency, both the simple virilizing and salt losing form, primary aldosteronism, renal hypertension and cystinosis. Our findings suggest that K-M1 may be formed from 21-deoxyaldosterone and/or by microbial intervention from aldosterone or its metabolites.

21-Deoxyaldosterone excretion in patients with primary aldosteronism and 21-hydroxylase deficiency

21-Deoxyaldosterone appears in urine in free and conjugated forms. Total excretion is best determined after acid hydrolysis (pH 1) of urine, followed by extraction, repeated chromatographic purification, and quantitation of the steroid by RIA. 21-Deoxyaldosterone excretion was normal in 70% of patients with essential hypertension (n = 18), while 30% (n = 8) had more or less elevated values. In patients with primary aldosteronism (n = 21) elevated as well as normal values of urinary 21-deoxyaldosterone were found, indicating that in some patients aldosterone may be formed not only from corticosterone but also from the 21-deoxy compound. In patients with 21-hydroxylase deficiency (n = 21) urinary 21-deoxyaldosterone was invariably elevated, whether the patients had the virilizing or salt-losing form of the disease. Although the clinical manifestations of the salt-losing form seem unrelated to the inability to convert 21-deoxyaldosterone to aldosterone, the determination of 21-deoxyaldosterone adds insight into the biosynthesis of aldosterone in primary aldosteronism and 21-hydroxylase deficiency.

Radioimmunoassay of urinary 21-deoxytetrahydroaldosterone in primary aldosteronism and 21-hydroxylase deficiency

A radioimmunoassay of 21-deoxytetrahydroaldosterone was developed. Normal daily excretion of the unconjugated metabolite was 1.2 +/- 1.3 micrograms and of the glucuronized metabolite, 11.9 +/- 7 micrograms. The tetrahydroaldosterone/21-deoxytetrahydroaldosterone ratio varied more in patients with primary aldosteronism than in control subjects. Thus, measurements of the urinary excretion of the tetrahydroaldosterone or 21-deoxytetrahydroaldosterone alone did not provide an accurate expression for aldosterone production. Their sum correlated well with the clinical condition, i.e. clear-cut elevation in patients with primary aldosteronism. The diminished tetrahydroaldosterone/21-deoxytetrahydroaldosterone ratio found in patients with 21-hydroxylase deficiency may be attributed to increased bacterial conversion of tetrahydroaldosterone to 21-deoxytetrahydroaldosterone but could also stem from a deficiency implicating zona glomerulosa (aldosterone biosynthesis) regardless of the stage and clinical presentation of the disease.