Antioxidant effects of piperine on steroid-induced hepatotoxicity.

OBJECTIVE: Glucocorticoids (GCs) are steroids that play an essential role in physiological processes and are valuable therapeutic agents against various diseases. The aim of our study was to evaluate the antioxidant effects of piperine (PIP) on steroid-induced oxidative stress in liver tissue. MATERIALS AND METHODS: We used 36 fertilized specific-pathogen-free (SPF) chicken eggs that were divided into the following 6 groups: group 1 (n=6), phosphate buffered saline (PBS) (pH 7.4 saline solution [0.9%] isotonic); group 2 (n=6), 0.50 µmol hydrocortisone succinate sodium (HC); group 3 (n=6), 0.50 µmol HC and 100 mg/kg piperine (PIP); group 4 (n=6), 0.50 µmol HC and 50 mg/kg PIP; group 5 (n=6), 0.50 µmol HC and 25 mg/kg PIP; and group 6 (n=6), 0.50 µmol HC and 10 mg/kg PIP. Chick embryos were removed from the eggs and the livers dissected from the embryos. The total antioxidant status (TAS), total oxidant status (TOS), reduced glutathione (GSH), and lipid peroxidation (malondialdehyde [MDA]) levels were measured. RESULTS: The highest levels of GSH and TAS in the liver tissues were observed in group 3, with a significant difference from those in group 2 (p <0.001 and p =0.006, respectively). The lowest levels of MDA and TOS in the liver tissues were observed in group 3, with a significant difference from those in group 2 (p <0.001 and p =0.021, respectively). CONCLUSIONS: The antioxidant and hepatoprotective properties of PIP were observed only at high doses.

Induction of aortic valve calcification by celecoxib and its COX-2 independent derivatives is glucocorticoid-dependent.

BACKGROUND: Celecoxib, a selective cyclooxygenase-2 inhibitor, was recently associated with increased incidence of aortic stenosis and found to produce a valvular calcification risk in vitro. Several cyclooxygenase-2 independent celecoxib derivatives have been developed and identified as possible therapies for inflammatory diseases due to their cadherin-11 inhibitory functions. Potential cardiovascular toxicities associated with these cyclooxygenase-2 independent celecoxib derivatives have not yet been investigated. Furthermore, the mechanism by which celecoxib produces valvular toxicity is not known. METHODS AND RESULTS: Celecoxib treatment produces a 2.8-fold increase in calcification in ex vivo porcine aortic valve leaflets and a more than 2-fold increase in calcification in porcine aortic valve interstitial cells cultured in osteogenic media. Its cyclooxygenase-2 independent derivative, 2,5-dimethylcelecoxib, produces a similar 2.5-fold increase in calcification in ex vivo leaflets and a 13-fold increase in porcine aortic valve interstitial cells cultured in osteogenic media. We elucidate that this offtarget effect depends on the presence of either of the two media components: dexamethasone, a synthetic glucocorticoid used for osteogenic induction, or cortisol, a natural glucocorticoid present at basal levels in the fetal bovine serum. In the absence of glucocorticoids, these inhibitors effectively reduce calcification. By adding glucocorticoids or hydrocortisone to a serum substitute lacking endogenous glucocorticoids, we show that dimethylcelecoxib conditionally induces a 3.5-fold increase in aortic valve calcification and osteogenic expression. Treatment with the Mitogen-activated protein kinase kinase inhibitor, U0126, rescues the offtarget effect, suggesting that celecoxib and dimethylcelecoxib conditionally augment Mitogen-activated protein kinase kinase/extracellular-signal-regulated kinase activity in the presence of glucocorticoids. CONCLUSION: Here we identify glucocorticoids as a possible source of the increased valvular calcification risk associated with celecoxib and its cyclooxygenase-2 independent derivatives. In the absence of glucocorticoids, these inhibitors effectively reduce calcification. Furthermore, the offtarget effects are not due to the drug's intrinsic properties as dual cyclooxygenase-2 and cadherin-11 inhibitors. These findings inform future design and development of celecoxib derivatives for potential clinical therapy.

Effects of the glucocorticoid clobetasol propionate and its mixture with cortisol and different class steroids in adult female zebrafish.

Ecotoxicological effects of glucocorticoids and steroid mixtures in the environment are not sufficiently known. Here we investigate effects of 11-14 days exposure of female zebrafish to the glucocorticoid clobetasol propionate (Clo), cortisol (Cs), their mixture and mixtures with five different class steroids (Clo + triamcinolone + estradiol + androstenedione + progesterone) in liver, brain and gonads. Cs showed little activity, while Clo reduced the condition factor at 0.57 and 6.35 µg/L. Clo induced differential expression of genes in the liver at 0.07-6.35 µg/L, which were related to circadian rhythm (per1, nr1d2), glucose metabolism (g6pca, pepck1), immune system response (fkbp 5, socs3, gilz), nuclear steroid receptors (pgr and pxr), steroidogeneses and steroid metabolism (hsd11b2, cyp2k22). Clo caused strong transcriptional down-regulation of vtg. Similar upregulations occurred in the brain for pepck1, fkbp5, socs3, gilz, hsd11b2, and nr1d2a, while cyp19b was down-regulated. Effects of Clo + Cs mixtures were similar to Clo alone. Transcriptional alterations were different in mixtures of five steroids with no alteration of vtg in the liver due to counteraction of Clo and estradiol. Induction of fkbp5 (brain) and sult2st3 (liver) and downregulation of cyp19a (gonads) occurred at 1 µg/L. Histological effects of the five steroids mixture in gonads were characterized by a decrease of mature oocytes. Our data indicate that effects of steroids of different classes sum up to an overall joint effect driven by the most potent steroid Clo.

Anticataractogenic effect of betaine in chick embryo hydrocortisone-induced cataract model.

Background & objectives: Cataract is one of the leading causes of blindness in the world. The aim of the present study was to investigate anticataractogenic effect of betaine in chick embryo hydrocortisone (HC)-induced cataract model. Methods: The study included 60 fertilized eggs divided into six groups each having 10 eggs: one group treated with only HC (HC group); three treated with both HC and different doses of betaine (HC/B 1.00, HC/B 0.50 and HC/B 0.25 groups) and two non-HC groups treated with only phosphate-buffered saline (PBS group) or betaine (B group). After the injections, lenses of the embryos were removed and classified into five stages according to the lens opacification. The amounts of reduced glutathione (GSH) in the removed lenses were measured. Results: All the lenses in non-HC-treated groups were clear, whereas in the HC-treated group, 90 per cent of the lenses had cataract (stages 4 and 5). The mean score of lens opacity was significantly lower in all HC/B groups compared to HC group (2.4-3.5 vs. 4.4, P<0.05). Among HC/B groups, the HC/B 0.25 group had significantly lower mean score of lens opacity compared to remaining HC/B groups treated with higher doses of betaine. In addition, the mean reduced GSH level was significantly higher in HC/B 0.25 group compared to HC, HC/B 1.00 and HC/B 0.50 groups (P<0.001). Interpretation & conclusions: The present results show beneficial anti-cataract and anti-oxidant effects of 0.25 µmol/egg betaine on HC-induced cataract in the chick embryo.

Metabolic profiling reveals therapeutic biomarkers of processed Aconitum carmichaeli Debx in treating hydrocortisone induced kidney-yang deficiency syndrome rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Kidney-yang deficiency syndrome (KYDS) is a diagnostic pattern in traditional Chinese medicine (TCM) and clinical data showed that the unbalance in adrenal cortical hormone is the key issue in KYDS patients. The processed Ranunculaceae aconitum carmichaeli debx (bai-fu-pian in Chinese, BFP) is one of the most commonly used Chinese herbs for treating KYDS. The present study was conducted to explore the therapeutic biomarkers of the BFP in treating hydrocortisone administration induced KYDS rats. MATERIALS AND METHODS: Thirty male Sprague-Dawley rats were randomly divided into five groups with six in each group. KYDS in rats was induced by i.p. injection of hydrocortisone at the dose of 10mg/kg per day for 15 days as described previously. The rats with KYDS were administered orally, starting from the day of hydrocortisone administration stopped, with BFP extract at the dose of 0.32g/kg, 0.64g/kg and 1.28g/kg per day respectively for 15 days. The blood samples were collected for the liquid chromatography quadruple time-of-flight mass spectrometry (LC-Q-TOF-MS) test, as well as radioimmunoassay to determine the concentrations of cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP) and adrenocorticotrophic hormone (ACTH). The metabolic responses to BFP administration were investigated by using the principal components analysis (PCA) and orthogonal partial least squares analysis (OPLS). Bioinformatics analyses were performed by using the Ingenuity Pathway Analysis (IPA). Variance analysis and linear regression analysis were used in this study. RESULTS: The signs and concentrations of cAMP, cGMP and ACTH in the model rats were similar to those previously described about KYDS rats and BFP treatment can reverse the changes. Seventeen significantly changed metabolites among different groups were identified. Thirteen metabolites were identified in the KYDS rats comparing to healthy rats with nine up-regulated and four down-regulated. After BFP treatment at three dosages, five up-regulated metabolites including phosphate, betaine, (4-hydroxyphenyl) acetaldehyde, 5-hydroxyindol-3-acetic acid and 5'-phosphoribosyl-N-formylglycinamide were dose-dependently reversed. The network analysis with IPA showed that four canonical pathways including superpathway of methionine degradation, purine nucleotides de novo biosynthesis II, tyrosine synthesis and serotonin receptor signaling involved the therapeutic mechanism of BFP in treating the KYDS rats. CONCLUSIONS: Five therapeutic biomarkers (phosphate, betaine, (4-hydroxyphenyl) acetaldehyde, 5-hydroxyindol-3-acetic acid and 5'-phosphoribosyl-N-formylglycinamide) and two corresponding canonical pathways (amino acid metabolism and purine nucleotide metabolism) were identified to be involved in the therapeutic mechanism of BFP treating the KYDS.

Cortisol stimulates proliferation and apoptosis in the late gestation fetal heart: differential effects of mineralocorticoid and glucocorticoid receptors.

We have previously found that modest chronic increases in maternal cortisol result in an enlarged fetal heart. To explore the mechanisms of this effect, we used intrapericardial infusions of a mineralocorticoid receptor (MR) antagonist (canrenoate) or of a glucocorticoid receptor (GR) antagonist (mifepristone) in the fetus during maternal infusion of cortisol (1 mg·kg⁻¹·day⁻¹). We have shown that the MR antagonist blocked the increase in fetal heart weight and in wall thickness resulting from maternal cortisol infusion. In the current study we extended those studies and found that cortisol increased Ki67 staining in both ventricles, indicating cell proliferation, but also increased active caspase-3 staining in cells of the conduction pathway in the septum and subendocardial layers of the left ventricle, suggesting increased apoptosis in Purkinje fibers. The MR antagonist blocked the increase in cell proliferation, whereas the GR antagonist blocked the increased apoptosis in Purkinje fibers. We also found evidence of activation of caspase-3 in c-kit-positive cells, suggesting apoptosis in stem cell populations in the ventricle. These studies suggest a potentially important role of corticosteroids in the terminal remodeling of the late gestation fetal heart and suggest a mechanism for the cardiac enlargement with excess corticosteroid exposure.

Long-term cytotoxic effects of contemporary root canal sealers

Objectives: The aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks. Material and Methods: Fibroblasts (3T3, 1×105 cells per well) were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex) and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test. Results: RoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05). All the other tested sealers exhibited severe toxicity initially (week 0). MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode.Conclusions: RoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.

Genes, environment, and orofacial clefting: N-acetyltransferase and folic acid.

Nonsyndromic orofacial clefting has been the subject of intense studies, both genetic and epidemiological. The findings have frequently been controversial because of lack of reproducibility. Mouse models provide the potential both for genetic and environmental uniformity. We have chosen to study the role of genetic susceptibility to teratogen-induced orofacial clefting, using 2 drugs (dilantin and corticosteroid) and 1 nondrug teratogen (6-aminonicotinamide). The strongest single genetic influence we have found is N-acetyltransferase 2. Our recent work and that of others suggest that the influence of this locus is mediated through alterations in folate metabolism. Our results support epidemiological findings in humans and possibly implicate altered cytosine methylation, potentially caused by environmental factors, at least in the A/J model.

Adrenal function status in patients with paracoccidioidomycosis after prolonged post-therapy follow-up.

This study assessed adrenal function in patients with paracoccididioidomycosis who had been treated to determine a possible connection between high antibody titers and adrenal dysfunction attributable to persistence of the fungus in adrenal gland. Adrenal gland function was studied in 28 previously treated patients, 2 (7.1%) of whom were shown to have adrenal insufficiency and 7 (259%) who showed a below normal response to stimuli by adrenocorticotropic hormone. Paracoccidioides brasiliensis was detected in the adrenal gland from one of the patients with adrenal insufficiency. Although the study failed to demonstrate a significant difference between high antibody titers and low cortisol levels, the proportion of adrenal insufficiency detected and the subnormal response to adrenocorticotropic hormone confirmed that adrenal damage is an important sequela of paracoccidioidomycosis. Studies with a larger number of patients should be conducted to confirm the hypothesis of persistence of P. brasiliensis in adrenal gland after therapy.

The estrogen-injected female mouse: new insight into the etiology of PCOS.

BACKGROUND: Female mice and rats injected with estrogen perinatally become anovulatory and develop follicular cysts. The current consensus is that this adverse response to estrogen involves the hypothalamus and occurs because of an estrogen-induced alteration in the GnRH delivery system. Whether or not this is true has yet to be firmly established. The present study examined an alternate possibility in which anovulation and cyst development occurs through an estrogen-induced disruption in the immune system, achieved through the intermediation of the thymus gland. METHODS, RESULTS AND CONCLUSION: A putative role for the thymus in estrogen-induced anovulation and follicular cyst formation (a model of PCOS) was examined in female mice by removing the gland prior to estrogen injection. Whereas all intact, female mice injected with 20 microg estrogen at 5-7 days of age had ovaries with follicular cysts, no cysts were observed in animals in which thymectomy at 3 days of age preceded estrogen injection. In fact, after restoring immune function by thymocyte replacement, the majority of thymectomized, estrogen-injected mice had ovaries with corpora lutea. Thus, when estrogen is unable to act on the thymus, ovulation occurs and follicular cysts do not develop. This implicates the thymus in the cysts' genesis and discounts the role of the hypothalamus. Subsequent research established that the disease is transferable by lymphocyte infusion. Transfer took place between 100-day-old estrogen-injected and 15-day-old naïve mice only when recipients were thymectomized at 3 days of age. Thus, a prerequisite for cyst formation is the absence of regulatory T cells. Their absence in donor mice was judged to be the result of an estrogen-induced increase in the thymus' vascular permeability, causing de facto circumvention of the final stages of regulatory T cell development. The human thymus has a similar vulnerability to steroid action during the fetal stage. We propose that in utero exposure to excessive levels of steroids such as estrogen has a long-term effect on the ability of the thymus to produce regulatory T cells. In female offspring this can lead to PCOS.

Low-potency glucocorticoid hydrocortisone has similar neurotoxic effects as high-potency glucocorticoid dexamethasone on neurons in the immature chicken cerebellum.

High-potency glucocorticoids (GC) are used in the prophylaxis and treatment of neonatal bronchopulmonal dysplasia, but there is concern about side effects on the developing brain. Recently, the low-potency GC hydrocortisone (HC) has been suggested as an alternative to high-potency GC. We compared the neurotoxic effects of HC with the high-potency GC dexamethasone (DEX) in chicken cerebellum. A single dose of GC was injected into the egg at embryonic day 16 and the death of granule neurons in histologic sections of the cerebellar cortex was examined 24 h later. DEX and HC showed a similar dose-dependent induction of morphological apoptosis and caspase-3 activation in the internal granular layer. A doubling of the apoptosis rate compared to the basal rate was seen for the highest dose of DEX (5 mg/kg) and medium dose of HC (1 mg/kg). In cultures of embryonic chicken cerebellar granule cells, DEX and HC increased cell death and induced rapid caspase-3 activation in a similar dose-dependent manner. Transfection of granule cells with a luciferase reporter gene revealed that the dose needed for the activation of gene transcription (classical signalling pathway) with DEX was much lower than for HC. In conclusion, HC does not present itself as a safer drug than DEX in this model. In addition, it appears that DEX and HC induce apoptosis in immature granule neurons via a non-genomic (non-classical) mechanism.

Immunotoxicity of bisphenol A to Carassius auratus lymphocytes and macrophages following in vitro exposure.

Bisphenol A (BPA) is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical (EDC). The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA (0.054-5.4 mg/L), estradiol (0.0002-2.0 mg/L) and hydrocortisone (5-50 mg/L) significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone (500-5000 mg/L) appeared to be inhibitory. BPA (0.005-50 mg/L), estradiol (0.005-800 mg/L) and hydrocortisone (0.005-500 mg/L) markedly enhanced macrophage proliferation, whereas higher doses of BPA (500-1000 mg/L) appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA (50 mg/L) and hydrocortisone (50 and 500 mg/L) suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested (0.05-500 mg/L). In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.

Effects of curcumin in treatment of experimental pulmonary fibrosis: a comparison with hydrocortisone.

To compare curcumin with hydrocortisone for treating bleomycin-induced pulmonary fibrosis (BLMPF), four groups of rats were injected with 1.5 mg/kg bleomycin intratracheally. Then the Group HC rats were treated with three injections of 2mg/kg hydrocortisone i.p.; Group CH and CL rats, respectively, were orally given 500 or 250 mg/kg curcumin daily; and Group PC rats were given deionized water alone. After 28 days of treatment, lung samples were examined by H-E staining, Masson's staining and immunohistochemical analyses and pulmonary type I collagen (Col-I), inducible nitric oxide synthetase (iNOS) and transforming growth factor-beta1 (TGF-beta1) were determined by Western blotting and real-time RT PCR analyses. The results showed that (1) Group PC rats had histopathological characteristics of BLMPF with significant increase in their protein/mRNA expressions of Col-I (+114%/+173%), iNOS (+146%/+523%) and TGF-beta1 (+476%/+527%) (P<0.01); (2) in Group HC, CH and CL rats, protein/mRNA expressions of Col-I (-39%/-52%, -31%/-57%, -33%/-58%), iNOS (-31%/-51%, -31%/-79%, -31%/-47%) and TGF-beta1 (-64%/-78%, -75%/-74%, -81%/-79%) were significantly lower than Group PC (P<0.05); (3) except for levels of TGF-beta1 protein, there was no significant difference among Group CH, CL and HC rats (P>0.05). It suggests that curcumin may play a similar role as hydrocortisone in preventing BLMPF.

In vivo comparison of the biocompatibility of two root canal sealers implanted into the subcutaneous connective tissue of rats.

OBJECTIVE: To evaluate the subcutaneous biocompatibility of 2 root canal sealers. STUDY DESIGN: The subcutaneous implant technique recommended by the Fédération Dentaire International (FDI) was used to test Endométhasone and EndoREZ root canal sealers. These materials were placed in Teflon tubes, 1 mm in diameter and 10 mm in length, and implanted into 2 pockets created in the back of 40 Calomys callosus rodents, 20 for each material. Tissue biopsies were collected and histologically examined 15, 30, 60, and 90 days after the implantation procedure. The overall level of the inflammatory tissue response was graded as none, slight, moderate, or severe on the sealer-connective tissue interface at the opening ends of the tubes. The connective tissue response along the lateral wall outside of each tube served as a negative control. RESULTS: The tissue reaction to the Endométhasone diminished with time. The EndoREZ sealer was highly toxic during all experimental periods. CONCLUSION: Endométhasone root canal sealer presented biocompatibility within the analyzed periods, whereas EndoREZ showed no biocompatible behavior and caused late hypersensitive reaction.

[Effects of AST and ASI on metabolism of free radical in senescent rats treated by HC].

OBJECTIVE: To study the effects of Astragaloside (AST) and Astragalus Saponin I (ASI) on metabolism of free radical and immune function in senescent rats treated by HC. METHOD: Hydrocorisone (HC) was used to estabilsh the aging model in rats. The content of molondialdehyde (MDA), glutathoine (GSH) and oxidized glutathoine (GSSG) in liver and brain was detected according to kit. The activity of Mn superoride dismulase (Mn-SOD) and catalase (CAT) was also surveyed by kit. Concanavalin (ConA) was used to detect the proliferation and interleukin-2 (IL-2) production of splenocytes. RESULT: Compared with HC control, AST and ASI could decrease the content of MDA, GSH and GSSG in liver and brain, increase the activity of Mn-SOD and CAT, and promote the proliferation and interleukin-2 (IL-2) activity of splenocytes. CONCLUSION: AST and ASI could delay the aging effect in rats treated by HC, and its mechanism maybe the antioxidant and regulating immunity.

Long-term outcome for men with androgen independent prostate cancer treated with ketoconazole and hydrocortisone.

PURPOSE: The combination of high dose ketoconazole and hydrocortisone (HDK) is active against androgen independent prostate cancer (AIPC). Median response times with HDK tend to be brief but a significant minority of AIPC patients benefit with extended responses. Well characterized response and survival information, especially in the cohort of patients who experience these longer, more durable, responses has not been previously reported. Characterization of this subgroup is of particular interest since men with long-term responses derive the greatest benefit from HDK therapy. MATERIALS AND METHODS: The medical records of 78 patients with AIPC treated with HDK between March 1991 and February 1999 were retrospectively reviewed. Baseline clinical and laboratory factors predictive of prolonged response and survival were identified. RESULTS: The median baseline prostate specific antigen (PSA) before the initiation of HDK was 25.1. The number of patients with zero, 1 to 3, and more than 3 lesions on bone scan were 25, 35 and 18, respectively. Median and mean time to PSA progression was 6.7 and 14.5 months. Median and mean survival time was 38.0 and 42.4 months, respectively. Response time and survival were highly correlated (r = 0.799). A total of 34 (44%) men had a greater than 75% decrease in PSA. The median survival times in men with more vs less than a 75% decrease were 60 vs 24 months, respectively. In a Cox proportional hazard regression, prolonged survival was predicted by percent PSA decrease, extent of disease on bone scan and baseline PSA. CONCLUSIONS: Ketoconazole can induce prolonged responses, occasionally lasting for years. Long responses are more likely to occur in men initiating HDK earlier in the course of disease before the cancer burden becomes excessive.

Steroid-induced short term diabetes in chick embryo: reversible effects of insulin on metabolic changes and cataract formation.

PURPOSE: To determine the reversible effect of insulin on glucocorticoid (GC)-induced cataract formation in relation to systemic metabolic changes in the developing chick embryo. METHODS: Hydrocortisone sodium succinate (HC; 0.25 micromoles) was administered to 15-day-old embryos followed by administration of long-acting recombinant human insulin, 4 and 28 hours later. At the indicated time after HC administration, the incidence of cataractous lenses and any changes in the components of the lenses, liver, and blood were determined. RESULTS: At 48 hours after HC administration, the following observations were made: opacification of lenses; an elevation of glucose and lipids in the blood and lenses; an increase in lipid peroxide (LPO) in the blood, liver, and lenses; a decrease in glutathione (GSH) in the lens and liver (at 24 hours after HC administration); and a depletion of adenosine triphosphate (ATP) in the liver. These changes in response to HC administration were reversed by a double application of insulin. CONCLUSIONS: Insulin antagonizes GC-induced gluconeogenesis, stimulates glycolysis, and ultimately leads to recovery of decreased activity in the citric acid cycle. The restoration of ATP by the recovered citric acid cycle may facilitate de novo synthesis of GSH, which in turn may diminish GC-induced elevation of LPO in the liver. Thus, the metabolic changes in response to HC-accelerated gluconeogenesis in the liver, which can be reversed by insulin, are likely to produce oxidative stress that leads to cataract formation. GC-induced metabolic changes in the liver, which are antagonized by insulin, may relate to production of one of the risk factors for cataract formation.

Spin-spin relaxation times in myocardial hypertrophy induced by endocrine agents in rat.

Magnetic resonance techniques afford a significant advantage for noninvasive diagnosis of cardiovascular pathology. The purpose of our present study was to assay the proton nuclear magnetic resonance (1H-NMR) sensitivity in the differential diagnosis of certain endocrine cardiovascular complications. In this context, we investigated the water state and content in the hypertrophied myocardium. Male and female Wistar rats were treated with different hormones (hydrocortisone acetate, testosterone, estradiol, thyroid hormones) in combination with isoproterenol (a synthetic catecholamine that induces myocardial ischemia and hypertrophy). The animals were sacrificed after 20 days of treatment and samples of integral myocardium and left ventricular myocardium were analyzed on a 1H-NMR AREMI spectrometer (0.6 T; proton resonance at 25 MHz). The estimation of T2 was made by Carr Purcell-Meiboom-Gill pulse sequence. The data were fitted to a bi-exponential curve, yielding short (T21) values for bound water and long (T22) values for free water. In order to evaluate the myocardial hypertrophy, the following ratios were calculated: integral myocardium to body weight; left ventricle to body weight; left ventricle to integral myocardium. The first two ratios were also calculated for dried tissue, in order to estimate its contribution to myocardial hypertrophy. Our findings demonstrate that myocardial hypertrophy is associated with a decrease of T22, as a consequence of the increase in the dried component (i.e. proteins) of the tissue, while the total tissue water (H2Ot%), measured by gravimetry) was not significantly modified. Nevertheless, it is reasonable that the increase in the protein content would be proportional with the increase in H2Ot%. The decrease of T21 seems to be proportional with the level of left ventricle hypertrophy in female groups. The 1H-NMR measurements were much sensitive for the differential diagnosis of myocardial hypertrophy in the case of left ventricle.

Cleft beak induced by hydrocortisone in the chick is prevented by increased cell division after experimental reduction of amniotic fluid.

Hypoplasia of the medial nasal process has been reported in chick embryos on embryonic day (ED) 5, 24 h after their exposure to hydrocortisone (HC). As a result, the cleft beak occurs in 80-100% of specimens on ED 9. In order to analyze its influence on cell proliferation, HC was injected intra-amniotically into embryos on ED 4, and the mitotic index and number of BrdU-positive cells were evaluated 24 h later, both in the epithelium and mesenchyme of the medial nasal processes, on serial frontal histological sections. Two hours after BrdU administration, there were 50% of labeled mesenchymal cells in the embryos exposed to HC and only 23% in the control group. The mitotic index of mesenchymal cells was significantly lower in the HC group than in the controls. The epithelium showed no significant difference. HC seemed to prevent the mesenchymal cells from entering mitosis. The cleft beak in the embryos exposed to HC on ED 4 was totally eliminated by tearing open the amnion (amniotomia) and allowing fluid to leak out on ED 5. In some of specimens exposed to HC, the mitotic index was investigated at six time intervals from 15 to 120 min after amniotomia. A significant increase in the mitotic index was detected in the mesenchymal cells of the medial nasal processes during the first hour after amniotomia. Such a prompt increase of the mitotic activity may be hypothetically explained by release of the HC from its receptor binding as a consequence of outflow of the amniotic fluid together with the HC pool, and freeing of the mesenchymal cells, blocked in the G2 phase, to enter mitosis. As a result, the hypoplasia of the medial nasal process might be compensated and the development of the cleft beak prevented.

Formation of free radicals from steroid hormones: possible significance in environmental carcinogenesis.

In order to clarify the mechanism of environmental carcinogenesis, steroid hormones were checked for formation of free radicals and active oxygen species. In alkaline DMSO in vitro, glucocorticoids, progestines, androgens and estrogens exhibited distinct ESR signals with characteristic hyperfine structures. Accumulated data on a great number of steroid derivatives suggest that an unpaired electron is localized at position 20 in the case of glucocorticoids, whereas it is at position 3 in other steroid hormones. Since experimental conditions include oxygenation reactions and more or less reflect enzymatic reactivity, the results obtained suggest further study on the physiological formation of free radicals from steroid hormone is warranted. Although detection of the free radicals of steroid hormones in several enzyme systems was limited to estrogens, evidence suggests that glucocorticoids as well as androgens may also share the physiological formation of free radicals. The production of active oxygen species was confirmed in certain cases.