[Subcutaneous transplants of juvenile rat testicular tissues continue to develop and secret androgen in adult rats].

Objective To explore the effects of subcutaneous microenvironment of adult rats on survival, development and androgen secretion of Leydig cells of transplanted juvenile rat testis. Methods Healthy adult SD rats were randomly divided into control group, sham group, castrated group and non-castrated group. Rats in the control group were kept intact, no testis was transplanted subcutaneously after adult recipients were castrated in the sham group; 5-7-day juvenile rat testes were transplanted subcutaneously in the castrated group, with one testis per side; Testes resected from juvenile rats were directly transplanted subcutaneously on both sides of the recipients in the non-castrated group. The grafts were obtained and weighed 4 weeks later. Then the histological features of the grafts were examined by HE staining; the expression and distribution of hydroxysteroid 17-beta dehydrogenase 1 (HSD-17ß1) were investigated by immunohistochemistry; and the serum androgen level was determined by ELISA. Results The average mass of grafts obtained from the castrated group was significantly higher than that of the non-castrated group. Immunohistochemistry indicated that Leydig cells were visible in the tissues from both the castrated and non-castrated groups, but the number of HSD-17ß1-posotive cells in the castrated group was larger than that in the non-castrated group. ELISA results showed that the serum androgen level was higher in the control group and non-castrated group than in the sham group and castrated group, and compared with the sham group, the serum androgen level in the castrated group was significantly higher. Conclusion The juvenile rat testis subcutaneously transplanted could further develop under the adult recipient rat skin, and the Leydig cells of grafts harbored the ability to produce and secret androgen.

Stromal markers AKR1C1 and AKR1C2 are prognostic factors in primary human breast cancer.

BACKGROUND: Stromal fibroblasts influence tumor growth and progression. We evaluated two aldo-keto reductases, AKR1C1 and AKR1C2, in stromal fibroblasts and carcinoma cells as prognostic factors in primary human breast cancer. They are involved in intratumoral progesterone metabolism. METHODS: Immunohistochemistry was performed on tissue microarrays from 504 core biopsies from breast cancer patients. Primary endpoints were disease-free (DFS) and overall (OS) survival. RESULTS: AKR1C1 and AKR1C2 expression in fibroblasts and tumor cells correlated with favorable tumor characteristics, such as small tumor size and negative nodal status. In univariate analysis, AKR1C1 expression in carcinoma cells correlated positively with DFS und OS; AKR1C2 expression in both fibroblasts and tumor cells also showed a positive correlation with DFS and OS. In multivariate analysis, AKR1C1 expression in carcinoma cells was an independent prognostic marker. CONCLUSION: It can be assumed that our observations are due to the independent regulatory function of AKR1C1/2 in progesterone metabolism and therefore provide a basis for new hormone-based therapy options for breast cancer patients, independent of classic hormone receptor status.

Neurological examination: pioneering authors and their books / Exame neurológico: autores pioneiros e seus livros

The objective of this article is to highlight some of the most important pioneering books specifically focused on the neurological examination and their authors. During the XIX Century, Alexander Hammond, William Gowers and Charles Mills pioneered the neurological literature, followed in the XX Century by Aloysio de Castro, Monrad-Krohn, Derek Denny-Brown, Robert Wartenberg, Gordon Holmes, and Russel DeJong. With determination and a marked sense of observation and research, they competently developed and spread the technique and art of the neurological exam.

O objetivo deste artigo é destacar alguns dos primeiros e mais importantes livros-texto interessados em difundir o ensino do exame neurológico e seus autores. Durante o século XIX, Alexander Hammond, William Gowers e Charles Mills foram pioneiros na literatura neurológica, seguidos por Aloysio de Castro, Monrad-Krohn, Derek Denny-Brown, Robert Wartenberg, Gordon Holmes e Russel DeJong no século XX. Com determinação, grande senso de observação e pesquisa, eles competentemente disseminaram a técnica e a arte de se realizar o exame neurológico.

The corticosteroid metabolic profile of the mouse.

Data are presented on the urinary corticosteroid metabolic profile of the mouse strain 129/svJ. Through the use of GC/MS we have characterized, or tentatively identified corticosterone (Kendall's compound B) metabolites of both the 11beta-hydroxy and 11-carbonyl (compound A) series in urine. Full mass spectra of the methyloxime-trimethylether derivatives of 15 metabolites are included in the paper as an aid to other researchers in the field. Metabolites ranged in polarity from tetrahydrocorticosterone (THB) to dihydroxy-corticosterone with dominance of highly polar steroids. We found that prior to excretion corticosterone can undergo oxidation at position 11beta, reduction at position 20 and A-ring reduction. Metabolites retaining the 3-oxo-4-ene structure can be hydroxylated at position 6beta- as well as at an unidentified position, probably 16alpha-. Saturated steroids can be hydroxylated at positions 1beta-, 6alpha-, 15alpha- and 16alpha. A pair of hydroxy-20-dihydro-corticosterone metabolites (OH-DHB) were the most important excretory products accounting for about 40% of the total. One metabolite of this type was identified as 6beta-hydroxy-DHB; the other, of similar quantitative importance was probably 16alpha-hydroxy-DHB. The ratio of metabolites of corticosterone (B) to those of 11-dehydro-corticosterone (A) was greater than 9:1, considerably higher than that for the equivalent "human" ratio of 1:1 for cortisol to cortisone metabolites. Results from this study allowed the evaluation of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) activity in mice with deleted glucose-6-phosphate transporter (G6PT). These mice had attenuated back-conversion of A to B resulting in an increased ratio of A-metabolites to B-metabolites [Walker EA, Ahmed A, Lavery GG, Tomlinson JW, Kim SY, Cooper MS, Stewart PM, 11beta-Hydroxysteroid dehydrogenase type 1 regulation by intracellular glucose-6-phosphate, provides evidence for a novel link between glucose metabolism and HPA axis function. J Biol Chem 2007;282:27030-6]. We believe this study is currently the most comprehensive on the urinary steroid metabolic profile of the mouse. Quantitatively less steroid is excreted in urine than in feces by this species but urine analysis is more straightforward and the hepatic metabolites are less subject to microbial degradation than if feces was analyzed.

Fluorogenic metabolic probes for direct activity readout of redox enzymes: Selective measurement of human AKR1C2 in living cells.

The current arsenal of tools and methods for the continuous monitoring and imaging of redox metabolic pathways in the context of intact cells is limited. Fluorogenic substrates allow for direct measurement of enzyme activity in situ; however, in contrast to proteases and exo-glycosidases, there are no simple guidelines for the design of selective probes for redox metabolic enzymes. Here, we introduce redox probe 1 and demonstrate its high selectivity in living cells for human hydroxysteroid dehydrogenases (HSDs) of the aldo-keto reductase (AKR) superfamily. AKR1C isoforms perform multiple functions among which the metabolism of potent steroid hormones is well documented. Moreover, expression of these enzymes is responsive to cellular stress and pathogenesis, including cancer. Our probe design is based on redox-sensitive optical switches, which couple a ketone-alcohol redox event to a profound change in fluorescence. The high selectivity of phenyl ketone 1 for AKR1C2 over the many endogenous reductases present in mammalian cells was established by a quantitative comparison of the metabolic rates between null control cells (COS-1) and AKR1C2-transfected cells. Phenyl ketone 1 is a cell-permeable fluorogenic probe that permits a direct, real-time, and operationally simple readout of AKR1C2 enzyme activity in intact mammalian cells. Furthermore, it was demonstrated that probe 1 enables the quantitative examination of physiological substrate 5alpha-dihydrotestosterone ("dark substrate") in situ by means of a two-substrate competitive assay. Similarly, inhibitor potency of physiological (ursodeoxycholate) and synthetic inhibitors (flufenamic acid, ibuprofen, and naproxen) was also readily evaluated.

Analysis of C-3 epimerization in (24R)-24,25-dihydroxyvitamin D3 catalyzed by hydroxysteroid dehydrogenase.

Studies on the C-3 epimerization in (24R)-24,25-dihydroxyvitamin D(3) [24R,25(OH)(2)D(3)] were performed using hydroxysteroid dehydrogenases (HSDs). 3-Epi-24R,25(OH)(2)D(3) was formed from 24R,25(OH)(2)D(3) by the catalysis of 3alpha- or beta-HSD. These HSDs also catalyzed the C-3 epimerization in 3-epi-24R,25(OH)(2)D(3) to form 24R,25(OH)(2)D(3). 24R,25(OH)(2)D(3) and its C-3 epimer were separated by inclusion high-performance liquid chromatography using gamma-cyclodextrin (gamma-CD) as the mobile phase additive or a gamma-CD bonded chiral column. The product derived from the intermediate during the C-3 epimerization was isolated from the incubation specimens and identified as (7Z)-(24R)-24,25-dihydroxy-9,10-secocholesta-4,7,10(19)-trien-3-one by several instrumental analyses including (1)H-nuclear magnetic resonance spectrometry. The occurrence of this compound strongly proves that the formation of the C-3 epimer by HSD involves a dehydrogenation process. The present study suggests that HSDs may catalyze the C-3 epimerization of vitamin D compounds and modulate their concentrations and biological activities in animals and humans.

Expression of estrogen receptors and enzymes involved in sex steroid metabolism in the rat tibia during sexual maturation.

Estrogens are essential for bone mass accrual but their role before sexual maturation has remained elusive. Using in situ hybridization and immunohistochemistry, we investigated the expression of both estrogen receptor (ER) alpha and beta mRNA and protein as well as several mRNAs coding for enzymes involved in sex steroid metabolism (aromatase, type I and II 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD), steroid sulfatase (STS) and type I 5 alpha-reductase) on sections of tibial metaphyses before (1- and 4-week-old), during (7-week-old) and after (16-week-old) sexual maturation in female and male rats. ER alpha and ER beta mRNA and protein were detected in metaphyseal bone in lining cells, osteoblasts, osteoclasts and some osteocytes with no apparent differences in expression during development or between the sexes. In contrast, aromatase, type I and II 17 beta-HSD and type I 5 alpha-reductase mRNAs were first detected in osteoblasts, osteoclasts and occasionally in osteocytes from sexual maturation (7-week-old rat) and onwards. Only STS was present before sexual maturation. To study the significance of ER alpha and beta expression in bone before sexual maturation when circulating sex steroid levels are low, 26-day-old female and male rats underwent gonadectomy or 17 beta-estradiol (E(2)) supplementation (0.5 mg/21 days) during 3 weeks. Following gonadectomy, trabecular bone volume (TBV) was lower in males (P=0.03) and there was a trend towards reduction in females (P=0.057). E(2) supplementation increased tibial TBV compared with controls in both genders as assessed by Masson-Goldner staining. These data suggest that the presence of ERs in bone cells before sex maturation might be of significance for bone mass accrual. Furthermore, based on the mRNA expression of the crucial enzymes aromatase and type I 17 beta-HSD, we suggest that bone cells in the tibial metaphysis acquire the intrinsic capacity to metabolize sex steroids from sexual maturation onwards. This process may contribute to the beneficial effects of estrogen on bone mass accrual, possibly by intracrinology.

11beta-hydroxysteroid dehydrogenase type 2 in mouse aorta: localization and influence on response to glucocorticoids.

Both isozymes of 11beta-hydroxysteroid dehydrogenase, which interconvert active and inactive glucocorticoids, are expressed in the mouse aortic wall. Mice deficient in 11HSD type 2 (which converts active corticosterone into inert 11-dehydrocorticosterone) have hypertension and impaired endothelial nitric oxide activity. It has been suggested that 11HSD2 influences vascular function directly by limiting glucocorticoid-mediated inhibition of endothelium-derived nitric oxide. This study sought to determine (1) the cellular distribution of the 11HSD isozymes within the mouse aortic wall and (2) the influence of 11HSD2 on direct glucocorticoid-mediated changes in aortic function. Mouse aortas were separated into their component layers and RNA extracted for RT-PCR. Both types of corticosteroid (mineralocorticoid and glucocorticoid) receptors and both 11HSD isozymes were expressed in the aortic wall. 11HSD1 expression colocalized with alpha-smooth muscle actin (a marker for smooth muscle cells), whereas 11HSD2 colocalized with TIE-2 (a marker for endothelial cells). Functional relaxation responses of mouse aortic rings were unaltered after exposure to glucocorticoids for 24 hours. In the presence of l-arginine, glucocorticoids produced an endothelium-independent reduction of contraction; similar results were obtained with aortas from mice with genetic inactivation of 11HSD2. Incubation in medium containing l-arginine reversed the endothelial cell dysfunction associated with 11HSD2 inactivation. Thus, 11HSD2 is appropriately sited to modulate endothelial cell function, but endothelial dysfunction in 11HSD2 knockout mice cannot be explained simply by increased access of corticosterone to endothelial cell corticosteroid receptors. Therefore, additional mechanisms, possibly involving indirect effects of enhanced corticosterone action in the kidney and the resultant hypertension, must be involved.

Expression of 11beta-hydroxysteroid dehydrogenase (11betaHSD) proteins in luteinizing human granulosa-lutein cells.

In a range of tIssues, cortisol is inter-converted with cortisone by 11beta-hydroxysteroid dehydrogenase (11betaHSD). To date, two isoforms of 11betaHSD have been cloned. Previous studies have shown that human granulosa cells express type 2 11betaHSD mRNA during the follicular phase of the ovarian cycle, switching to type 1 11betaHSD mRNA expression as luteinization occurs. However, it is not known whether protein expression, and 11betaHSD enzyme activities reflect this reported pattern of mRNA expression. Hence, the aims of the current study were to investigate the expression and activities of 11betaHSD proteins in luteinizing human granulosa-lutein (hGL) cells. Luteinizing hGL cells were cultured for up to 3 days with enzyme activities (11beta-dehydrogenase (11betaDH) and 11-ketosteroid reductase (11 KSR)) and protein expression (type 1 and type 2 11betaHSD) assessed on each day of culture. In Western blots, an immunopurified type 1 11betaHSD antibody recognized a band of 38 kDa in hGL cells and in human embryonic kidney (HEK) cells stably transfected with human type 1 11betaHSD. The type 2 11betaHSD antibody recognized a band of 48 kDa in HEK cells transfected with human type 2 11betaHSD cDNA but the type 2 protein was not expressed in hGL cells throughout the 3 days of culture. While the expression of type 1 11betaHSD protein increased progressively by 2.7-fold over 3 days as hGL cells luteinized, both 11betaDH and reductase activities declined (by 52.9% and 34.2%; P<0.05) over this same period. Changes in enzyme expression and activity were unaffected by the suppression of ovarian steroid synthesis.

Localization of 11beta-hydroxysteroid dehydrogenase types 1 and 2 in the male reproductive tract.

The action of glucocorticoids in target tissues is dependent on the local expression of glucocorticoid receptors and two 11beta-hydroxysteroid dehydrogenase (11beta-HSD) enzymes, 11beta-HSD1 and 11beta-HSD2, which interconvert active and inactive glucocorticoids. This study examined expression of the 11beta-HSD enzymes in the male reproductive tract of the adult rat. 11beta-HSD1 was immunolocalized to the apical region of principal epithelial cells of the caput epididymis, with the less numerous clear cells devoid of signal. Epididymal 11beta-HSD1 expression was confirmed by Western blot analysis, with immunoreactive species identified at 34 kDa (the expected size for 11beta-HSD1) and at approximately 48 kDa. 11beta-HSD bioactivity was readily detectable in the epididymis, with 11-oxoreductase activity clearly the favored reaction (as observed in liver), consistent with 11beta-HSD1 expression. The epithelium of the vas deferens, seminal vesicle, and penile urethra were also immunopositive for 11beta-HSD1, as were smooth muscle cells of the vas deferens and penile blood vessels. 11beta-HSD2 was also immunolocalized to the epididymal epithelium, but its distribution was complementary to that of 11beta-HSD1 (i.e. clear cells showing intense 11beta-HSD2 staining but principal cells devoid of signal). 11beta-HSD2 was also present in the corpora cavernosa of the penis but not in other tissues. In conclusion, the differential expression of 11beta-HSD1 and 11beta-HSD2 throughout the male reproductive tract suggests that these enzymes locally modulate glucocorticoid and mineralocorticoid actions, particularly in the epididymis and penile vasculature.

Expression of 11beta-hydroxysteroid dehydrogenases in bovine follicle and corpus luteum.

In glucocorticoid target organs, local concentrations of active glucocorticoid are determined by the relative expression of two 11beta-hydroxysteroid dehydrogenases (HSDs): bi-directional 11beta-HSD type1 (11HSD1) that mainly activates cortisone to cortisol, and dehydrogenase 11beta-HSD type2 (11HSD2) that inactivates cortisol to cortisone. In this study, we examined the expression of mRNA encoding these two 11beta-HSDs in bovine granulosa cells harvested from preovulatory follicles and corpora lutea (CL). Ovaries were obtained from Holstein cows at a local slaughterhouse. Follicles larger than 10 mm in diameter and CL were dissected and follicular fluid and granulosa cells were taken. Corpora lutea were weighed and their stages were morphologically assessed (stage I, days 1-4; stage II, days 5-10; stage III, days 11-17; stage IV, days 8-20). Follicles were classified into four groups according to their hormonal status (oestradiol (E(2)): progesterone (P(4))>1: oestrogen active; E(2):P(4)<1: oestrogen inactive) and stage of the oestrous cycle (luteal or follicular phase). Total RNA was extracted with phenol-chloroform and subjected to a semi-quantitative RT-PCR for 11HSD1, 11HSD2 and beta-actin. Concentrations of steroids in follicular fluid were determined by an enzyme immunoassay. In granulosa cells, only 11HSD1 mRNA was detected. There was a negative correlation between the expression of 11HSD1 and the concentration of cortisol in follicular fluid (P<0.05), indicating 11HSD1 may act as a dehydrogenase in the bovine follicle. Both types of 11beta-HSDs were expressed in CL. The levels of mRNA for both isozymes were high in stage I and II, and were decreased in stage III CL. In stage IV CL, the expression of 11HSD2 but not 11HSD1 mRNA increased. These results indicate that the bovine granulosa cells and CL express 11HSD1 and 11HSD2, and they may play an important physiological role in the bovine ovary through modulating the local glucocorticoid environment.

Regulation of 11 beta-hydroxysteroid dehydrogenase enzymes in the rat kidney by estradiol.

The 11beta-hydroxysteroid dehydrogenase (11betaHSD) type 1 (11betaHSD1) enzyme is an NADP+-dependent oxidoreductase, usually reductase, of major glucocorticoids. The NAD+-dependent type 2 (11betaHSD2) enzyme is an oxidase that inactivates cortisol and corticosterone, conferring extrinsic specificity of the mineralocorticoid receptor for aldosterone. We reported that addition of a reducing agent to renal homogenates results in the monomerization of 11betaHSD2 dimers and a significant increase in NAD+-dependent corticosterone conversion. Estrogenic effects on expression, dimerization, and activity of the kidney 11betaHSD1 and -2 enzymes are described herein. Renal 11betaHSD1 mRNA and protein expressions were decreased to very low levels by estradiol (E2) treatment of both intact and castrated male rats; testosterone had no effect. NADP+-dependent enzymatic activity of renal homogenates from E2-treated rats measured under nonreducing conditions was less than that of homogenates from intact animals. Addition of 10 mM DTT to aliquots from these same homogenates abrogated the difference in NADP+-dependent activity between E2-treated and control rats. In contrast, 11betaHSD2 mRNA and protein expressions were significantly increased by E2 treatment. There was a marked increase in the number of juxtamedullary proximal tubules stained by the antibody against 11betaHSD2 after the administration of E2. Notwithstanding, neither the total corticosterone and 11-dehydrocorticosterone excreted in the urine nor their ratio differed between E2- and vehicle-treated rats. NAD+-dependent enzymatic activity in the absence or presence of a reducing agent demonstrated that the increase in 11betaHSD2 protein was not associated with an increase in in vitro activity unless the dimers were reduced to monomers.

[Lectin of Yersinia pestis vaccine strain EV and its immunological properties]. / Lektin vaktsinnogo shtamma Yersinia pestis EV i izuchenie ego immunobiologicheskikh svoistv.

As the result of the chromatographic separation of Y. pestis EV membrane proteins, a protein fraction with hemagglutinating activity was obtained. The isolated preparation was glycoprotein with a molecular weight of 22 kD, contained 16% of carbohydrates and exhibited thermolabile properties. The determination of the carbohydrate specificity of this glycoprotein revealed that it belonged to the class of lectins. Changes in the content of 11 corticosteroids and the population composition of lymphocytes, as well as the detection of specific antibodies in the blood serum of guinea pigs immunized with lectin, were indicative of the fact that the preparation was sufficiently immunogenic and induced the activation of the processes of proliferation and activation of lymphocytes during immunogenesis. The lectin isolated from Y. pestis EV outer membrane may be regarded as an additional factor ensuring the contact of the pathogen with the cells of the body and as a promising component of combined plague vaccine.

Role of local 11 beta-hydroxysteroid dehydrogenase type 2 expression in determining the phenotype of adrenal adenomas.

It is not understood why some adrenal adenomas are nonfunctional and others with similar histopathology cause preclinical or overt Cushing's syndrome. Two isozymes of 11 beta-hydroxysteroid dehydrogenase, types 1 and 2 (HSD11B1 and HSD11B2), are known to modulate glucocorticoid levels in other tissues and might influence circulating levels of active and inactive glucocorticoids if they were expressed in adrenal adenomas. We determined levels of expression of these isozymes in normal adrenals and 61 adrenal adenomas by quantitative competitive RT-PCR and immunohistochemistry. There were no differences in HSD11B1 mRNA levels among adrenal tumor groups. HSD11B2 mRNA levels were high in nonfunctioning adenomas and preclinical Cushing's adenomas compared with levels in control adrenals or in adenomas causing overt Cushing's syndrome. HSD11B2 immunoreactivity was not detected in control adrenals, but was observed in more than half of these tumors. When nonfunctioning adenomas and those causing preclinical and overt Cushing's syndrome were considered as a single group, HSD11B2 mRNA levels were strongly correlated with the ratio of plasma cortisone to cortisol, and a simple model incorporating adrenal HSD11B2 expression and tumor size as variables could predict more than 50% of the interindividual variation in plasma cortisol levels (r(2) = 0.54; P < 0.0001). Adrenal HSD11B2 may regulate levels of active and inactive glucocorticoids in the systemic circulation under these conditions, presumably by acting in an autocrine or paracrine manner. Nonfunctioning adenomas and those causing preclinical and overt Cushing's syndrome may represent a continuum with clinical manifestations depending mainly on tumor size and HSD11B2 expression levels.

Effects of cortisol and oestradiol on hepatic 11beta-hydroxysteroid dehydrogenase type 1 and glucocorticoid receptor proteins in late-gestation sheep fetus.

In the late-gestation sheep, increased fetal plasma cortisol concentration and placental oestradiol (E(2)) output contribute to fetal organ maturation, in addition to the onset of parturition. Both cortisol and E(2) are believed to regulate the enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), which interconverts bioactive 11-hydroxy glucocorticoids and their inactive 11-keto metabolites. 11beta-HSD1, abundantly expressed in fetal liver, operates primarily as a reductase enzyme to produce bioactive cortisol and thus regulates local hepatic glucocorticoid concentrations. Cortisol acts through the glucocorticoid receptor (GR) present in the liver. In this study, we examined the effects of cortisol and E(2) on hepatic 11beta-HSD1 and GR in the liver of chronically catheterized sheep fetuses treated with saline (n=5), cortisol (1.35 mg/h; n=5), saline+4-hydroxyandrostendione, a P450 aromatase inhibitor (4-OHA; 1.44 mg/h; n=5), or cortisol+4-OHA (n=5). Cortisol infusion resulted in increased plasma concentrations of fetal cortisol and E(2); concurrent administration of 4-OHA attenuated the increase in plasma E(2) concentrations. Using immunohistochemistry, we showed that fetal hepatocytes expressed both 11beta-HSD1 and GR proteins. Cortisol treatment increased GR in both cytosol and nuclei of hepatocytes; concurrent administration of 4-OHA was associated with distinct nuclear GR staining. Western blot revealed that cortisol, in the absence of increased E(2) concentrations, significantly increased concentrations of 11beta-HSD1 (34 kDa) and GR (95 kDa) proteins. 11beta-HSD1 enzyme activity was measured in the liver microsomal fraction in the presence of [(3)H]cortisone (10(-)(6) M) or [(3)H]cortisol (10(-)(6) M) and NADPH (reductase activity) or NADP(+) (dehydrogenase activity) respectively. 11beta-HSD1 reductase activity was significantly greater in the presence of cortisol. In summary, we found that, in sheep during late gestation, cortisol increased both 11beta-HSD1 and GR in the fetal liver, and these effects were accentuated in the absence of increased E(2).

Gestation-related and betamethasone-induced changes in 11beta-hydroxysteroid dehydrogenase types 1 and 2 in the baboon placenta.

OBJECTIVE: We determined developmental and labor-related changes in 11beta-hydroxysteroid (HSD) 1 and 2 expression in baboon placentas during the final third of gestation and labor. We examined whether maternal glucocorticoid administration alters placental 11beta-HSD 2 expression. STUDY DESIGN: Maternal and fetal plasma cortisol concentrations were measured in five animals. Types 1 and 2 11beta-HSD messenger RNA (mRNA) and protein in placentas obtained at 121 to 185 days' gestation (dGA, term approximately 185 dGA, n = 16), during labor between 141 and 193 dGA (n = 8), and after maternal administration of four doses of 87.5 microg/kg betamethasone (n = 5) at 12-hour intervals at 121 to 135 dGA were analyzed by Northern and Western blot. RESULTS: Cortisol levels were higher in maternal plasma than fetal (4-fold, P <.mob031). Placental 11beta-HSD 2 mRNA and protein decreased after 0.9 gestation (P <.001). 11beta-HSD 1 mRNA remained unchanged. There was no effect of labor on placental 11beta-HSD 1 and 2 mRNA and protein levels. Maternal betamethasone administration dramatically increased (P <.05) 11beta-HSD 2 mRNA as well as protein without effect on 11beta-HSD 1 mRNA and protein expression. CONCLUSIONS: The late-gestation baboon maternal plasma cortisol concentration is four times the fetal plasma concentration. Decreased placental 11beta-HSD 2 may enhance maternal cortisol passage to the fetus at the end of gestation, thereby contributing to cortisol-mediated changes within the placenta and cortisol in fetal plasma at this stage of fetal development. The positive effect of betamethasone on placental 11beta-HSD 2 induction further suggests an ability of the placenta to regulate glucocorticoid transfer in the presence of elevated maternal glucocorticoid.

11Beta-hydroxysteroid dehydrogenase 1 expression in squamous cell carcinomas of the head and neck.

11Beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) has been identified as a major detoxification enzyme of one of the most potent tobacco smoke-derived carcinogens, NNK. If not metabolized by 11beta-HSD1, activation of NNK by cytochrome p450 mono-oxidase 2D6 (CYP2D6) results in an electrophile intermediate responsible for DNA damage. Interindividual variability in the expression of 11beta-HSD1 and CYP2D6 has been found to influence the susceptibility to lung cancer. The aim of this study was to compare 11beta-HSD1 mRNA expression and CYP2D6 metabolizer status in pharyngeal tissues of patients with oropharyngeal carcinoma and controls. In 20 patients with oropharyngeal cancer and 15 non-smoking controls, the 11beta-HSD1 mRNA expression was assessed with RT-PCR. The frequency of genetic polymorphisms of the CYP2D6 gene was assessed using RFLP. It was found that 11beta-HSD1 mRNA is expressed in human pharyngeal mucosa. It is upregulated in mucosa exposed to tobacco smoke. In tumour tissues, 11beta-HSD1 expression was significantly lower than in non-affected mucosa. The frequency distribution of CYP2D6 gene polymorphisms was similar in patients and controls. Chronic tobacco abuse results in 11beta-HSD1 enzyme induction. A reduction of 11beta-HSD1 expression in tumour tissues could be a consequence of malignantly transformed cells. It remains unclear if the lower 11beta-HSD1 expression gives rise to an increased rate of additional mutations.

Trends of reproductive hormones in male rats during psychosocial stress: role of glucocorticoid metabolism in behavioral dominance.

Stress in socially subordinate male rats, associated with aggressive attacks by dominant males, was studied in a group-housing context called the visible burrow system (VBS). It has been established that subordinate males have reduced serum testosterone (T) and higher corticosterone (CORT) relative to dominant and singly housed control males. The relationship of the decreased circulating T levels in subordinate males to changes in serum LH concentrations has not been evaluated previously. Since decreases in LH during stress may cause reductions in Leydig cell steroidogenic activity, the present study defined the temporal profiles of serum LH, T, and CORT in dominant and subordinate males on Days 4, 7, and 14 of a 14-day housing period in the VBS. The same parameters were followed in serum samples from single-housed control males. Leydig cells express glucocorticoid receptors and may also be targeted for direct inhibition of steroidogenesis by glucocorticoid. We hypothesize that Leydig cells are protected from inhibition by CORT at basal concentrations through oxidative inactivation of glucocorticoid by 11beta-hydroxysteroid dehydrogenase (11betaHSD). However, Leydig cell steroidogenesis is inhibited when 11betaHSD metabolizing capacity is exceeded. Therefore, 11betaHSD enzyme activity levels were measured in Leydig cells of VBS-housed males at the same time points. Significant increases in LH and T relative to control were observed in the dominant animals on Day 4, which were associated with the overt establishment of behavioral dominance as evidenced by victorious agonistic encounters. Serum LH and T were lower in subordinate males on Day 7, but T alone was lower on Day 14, suggesting that lowered LH secretion in subordinates may gradually be reversed by declines in androgen-negative feedback. Serum CORT levels were higher in subordinate males compared to control at all three time points. In contrast, oxidative 11betaHSD activity in Leydig cells of dominant males was higher relative to control and unchanged in subordinates. These results suggest the following: 1) failure of Leydig cells of subordinate males to compensate for increased glucocorticoid action during stress, by increasing 11betaHSD oxidative activity, potentiates stress-mediated reductions in T secretion; and 2) an inhibition of the reproductive axis in subordinate males at the level of the pituitary.

Repeated maternal glucocorticoid administration and the developing liver in fetal sheep.

Prenatal glucocorticoid exposure has been associated with a reduction in birth weight and postnatal alterations in glucose homeostasis and hypothalamic-pituitary-adrenal (HPA) axis function. The mechanisms underlying these responses are unknown, although changes in fetal hepatic development may play an important role. The fetal liver produces key regulators of fuel metabolism and of the developing HPA axis that are altered by glucocorticoids. The local availability of glucocorticoids is regulated, in part, by corticosteroid-binding protein (CBG), glucocorticoid receptors (GR) and by the enzyme 11beta-hydroxysteroid dehydrogenase (11betaHSD), but the effects of maternal glucocorticoid administration on the expression of these genes in the fetal liver are unknown. 11betaHSD1 is the predominant form of this enzyme present in the liver and is responsible for the conversion of cortisone to cortisol. To determine if prenatal glucocorticoid exposure alters fetal hepatic regulation of CBG, 11betaHSD1 and GRs, we treated pregnant ewes with betamethasone (0.5 mg/kg) intramuscularly at 104, 111 and 118 days of gestation (term 150 days). Animals were killed at 125 or 146 days of gestation. Maternal betamethasone administration did not alter mean cord plasma glucose but significantly decreased cord plasma insulin levels (P<0.05) at 125 days of gestation. At 146 days of gestation, cord plasma glucose levels were significantly increased without alterations in insulin levels following maternal betamethasone treatment (P<0.05). Maternal betamethasone administration resulted in a significant increase in fetal hepatic 11betaHSD1 mRNA and protein levels at 125 days of gestation (P<0.05). CBG mRNA levels were significantly elevated over control at 125 days although levels of CBG protein were not significantly different. GR protein levels were not statistically different at either 125 or 146 days of gestation following glucocorticoid administration. These data suggest that prenatal betamethasone exposure in the ovine fetus results in alterations in cord glucose and insulin levels as well as alterations in hepatic 11betaHSD1 mRNA and protein expression. These changes in 11betaHSD1 increase the potential to generate local cortisol from circulating cortisone. We speculate that this could affect expression of glucocorticoid-dependent hepatic enzymes involved with the regulation of glucose production and HPA responsiveness.