Regulation of Neuronal Stem Cell Proliferation in the Hippocampus by Endothelial Ceramide.

BACKGROUND/AIMS: Major depressive disorder is one of the most common diseases in western countries. The disease is mainly defined by its psychiatric symptoms. However, the disease has also many symptoms outside the central nervous system, in particular cardiovascular symptoms. Recent studies demonstrated that the acid sphingomyelinase/ceramide system plays an important role in the development of major depressive disorder and functions as a target of antidepressants. METHODS: Here, we investigated (i) whether ceramide accumulates in endothelial cells in the neurogenetic zone of the hippocampus after glucocorticosterone-mediated stress, (ii) whether ceramide is released into the extracellular space of the hippocampus and (iii) whether extracellular ceramide inhibits neuronal proliferation. Ceramide was determined in endothelial cell culture supernatants or extracellular hippocampus extracts by a kinase assay. Endothelial ceramide in the hippocampus was analyzed by confocal microscopy of brain sections stained with Cy3-labelled anti-ceramide antibodies and FITC-Isolectin B4. Neuronal proliferation was measured by incubation of pheochromocytoma neuronal cells with culture supernatants and extracellular hippocampus extracts. RESULTS: Treatment of cultured endothelial cells with glucocorticosterone induces a release of ceramide into the supernatant. Likewise, treatment of mice with glucocorticosterone triggers a release of ceramide into the extracellular space of the hippocampus. The release of ceramide is inhibited by concomitant treatment with the antidepressant amitriptyline, which also inhibits the activity of the acid sphingomyelinase. Studies employing confocal microscopy revealed that ceramide is formed and accumulates exclusively in endothelial cells in the hippocampus of stressed mice, a process that was again prevented by co-application of amitriptyline. Ceramide released in the culture supernatant or into the extracellular space of the hippocampus reduced proliferation of neurons in vitro. CONCLUSION: The data suggest a novel model for the pathogenesis of major depressive disorder, i.e. the release of ceramide-enriched microvesicles from endothelial cells that negatively affect neuronal proliferation in the hippocampus, but may also induce cardiovascular disease and other systemic symptoms of patients with major depressive disorder.

[N-stearoylethanolamine effect on the level of 11-hydroxycorticosteroids, cytokines IL-1, IL-6 and TNFalpha in rats with nonspecific inflammation caused by thermal burn of skin].

The mechanisms of anti-inflammatory action of saturated N-acylethanolamine--N-stearoylethanolamine (NSE) were investigated on the rat model of nonspecific inflammation (thermal burns of the skin). The results showed that the NSE application in a form of aqueous suspension (10 mg/ml) on the damaged skin area during 12 days significantly accelerated the healing process of burned wounds. NSE also prevented the increase of 11-hydroxycorticosteroids content in the blood of rats with burns. There was also found a significant decrease of cytokines (IL-1beta, IL-6 and TNFalpha) levels under the NSE action. This way may be one of the mechanisms of NSE anti-inflammatory action.

Immunorehabilitating effect of ultrahigh frequency electromagnetic fields in immunocompromised animals.

We observed immunorehabilitation effects of ultrahigh frequency electromagnetic fields (microwaves) in immunocompromised animals. It was shown that microwave irradiation of the thyroid gland area could abolish actinomycin D- and colchicine-induced immunosuppression and did not affect immunosuppression caused by 5-fluorouracil. These findings suggest that changes in the hormonal profile of the organism during microwave exposure can stimulate the processes of transcription and mitotic activity of lymphoid cells.

[Characteristization of the human microencapsulated adrenal cortex tissue in long-term culture].

Microencapsulated human adrenal cortex tissue preserves the ability to secrete 11-oxycorticosteroids for 51 days of cultivation, and to react adequately in responses to stimulation with adrenocorticotrophin and inhibition with chloditane, suggesting good prospects of the use of this tissue for compensation of the hypofunctional state of adrenocorticotropin system in experimental animals.

[The modelling of N-stearoylethanolamine effect of 17beta-estradiol in the organism of male rats].

The influence of N-stearoylethanolamine (NSE) on total 11-hydroxycorticosteroids (11-HCS) and testosterone level in the blood of male rats in normal conditions and under the action of 17beta-estradiol (400 mkg/kg of body weight during 3 days) was studied. It was shown that NSE administration per os (50 mg/kg of body weight during 7 days) to intact animals did not change the level of 11-HCS and of testosterone. The administration of NSE to estrogenized male rats decreased the elevated level of 11-HCS and normalized the amount of testosterone in blood. The correction of alterated weight of adenohypophysis and testis of estrogenized male rats compared to control can be a direct evidence of NSE-mediated modelling of the effect on hypothalamic-pituitary hormone system. The effect of NSE in the testis of estrogenized male rats inhibited the process of lipid peroxidation, caused the decrease of the amount of thiobarbituric acid reactive substances and increased the activity of superoxide dismutase and catalase. The NSE showed more expressed antioxidative effect compared to vitamin E. Taking into consideration all above mentioned data we suggested that NSE administration to male rats protected Leydig cells from damage under the increase of estrogen level.

Identification of steroid biosynthetic defects in genotype-proven heterozygous individuals for 17alpha-hydroxylase/17,20-lyase deficiency.

OBJECTIVE: P450c17 deficiency (17alpha-hydroxylase/17,20-lyase deficiency, 17OHD) is a rare form of congenital adrenal hyperplasia caused by CYP17A1 gene mutations. The D487_F489 deletion in exon 8 and Y329fs in exon 6 are relatively frequent mutations of the CYP17A1 gene in China that completely abolish the enzyme activity of P450c17. However, little remains known about steroid biosynthetic functions in carriers with these mutations in a single allele of the CYP17A1 gene, who are assumed to have 50% P450c17 activity. We investigated adrenal steroidogenic function in genotype-proven heterozygotes carrying such mutations in the CYP17A1 gene in vivo. PATIENTS AND DESIGN: Eight patients and fourteen family members from five families with 17OHD were recruited. The mutations of the CYP17A1 gene in these individuals were screened by sequencing. The hormonal response to cosyntropin (ACTH) was evaluated in the 14 genotype-proven carriers and 45 age- and gender-matched normal controls. RESULTS: Fourteen carriers of the CYP17A1 mutation - seven with the D487_F489 deletion, six with Y329fs and one with H373L - were identified from the five families with 17OHD. Compared with normal controls, carriers showed lower basal and ACTH-stimulated cortisol levels but higher ACTH-stimulated corticosterone levels. The ratios of corticosterone to cortisol in the genotype-proven heterozygotes were higher than those of the normal controls at the baseline and after cosyntropin stimulation. Similarly, the progesterone levels and the ratios of progesterone to 17-hydroxyprogesterone in the male heterozygotes were also higher than those of the normal controls, both before and after ACTH stimulation. CONCLUSION: Genotype-proven carriers of the CYP17A1 mutation who lack apparent clinical symptoms exhibit decreased adrenal 17alpha-hydroxylase activity and altered adrenal gland reserve for steroid biosynthesis.

[Effect of stress on the content of free radical oxidation products in subcellular brain fractions in rats of pubertal age].

The purpose of the present work is to study the influence of immobilization stress of different intensity on the content of protein and lipid oxidation products in subcellular brain fractions in rats of different age. It has been shown that 30-minute immobilization of 1.5-month, 2-month- and 12-month-old rats was not accompanied by accumulation of protein and lipid oxidation products in subcellular brain fractions. A prolonged immobilization of 1.5-month-old rats was accompanied by manifestations of oxidative stress in subcellular brain fractions; such manifestations were not characteristic of the rats of older age groups.

[Neurohumoral mechanisms of the rat heart adaptation to overload].

The present study confirms involvement of the sympathicoadrenal system in adaptation of heart to overload. Besides, at formation of chronic heart failure (CHF) there have been revealed a rise of the histamine and serotonin levels in blood plasma and myocardium as well as glucocorticoid hyperactivation.

Comparison of different enzyme-immunoassays for assessment of adrenocortical activity in primates based on fecal analysis.

Most studies published to date that used fecal glucocorticoid measurements to assess adrenocortical activity in primate (and many nonprimate) species applied a specific cortisol or corticosterone assay. However, since these native glucocorticoids are virtually absent in the feces of most vertebrates, including primates, the validity of this approach has recently been questioned. Therefore, the overall aim of the present study was to assess the validity of four enzyme-immunoassays (EIAs) using antibodies raised against cortisol, corticosterone, and reduced cortisol metabolites (two group-specific antibodies) for assessing adrenocortical activity using fecal glucocorticoid metabolite (GCM) measurements in selected primate species (marmoset, long-tailed macaque, Barbary macaque, chimpanzee, and gorilla). Using physiological stimulation of the hypothalamo-pituitary-adrenocortical (HPA) axis by administering exogenous ACTH or anesthesia, we demonstrated that at least two assays detected the predicted increase in fecal GCM levels in response to treatment in each species. However, the magnitude of response varied between assays and species, and no one assay was applicable to all species. While the corticosterone assay generally was of only limited suitability for assessing glucocorticoid output, the specific cortisol assay was valuable for those species that (according to high-performance liquid chromatography (HPLC) analysis data) excreted clearly detectable amounts of authentic cortisol into the feces. In contrast, in species in which cortisol was virtually absent in the feces, group-specific assays provided a much stronger signal, and these assays also performed well in the other primate species tested (except the marmoset). Collectively, the data suggest that the reliability of a given fecal glucocorticoid assay in reflecting activity of the HPA axis in primates clearly depends on the species in question. Although to date there is no single assay system that can be used successfully across species, our data suggest that group-specific assays have a high potential for cross-species application. Nevertheless, regardless of which GC antibody is chosen, our study clearly reinforces the necessity of appropriately validating the respective assay system before it is used.

[Effects of estradiol on synthesis of corticosteroids, protein kinase A and C activity in the adrenal cortex of intact and orchiectomized rats].

Estradiol treatment produced significant increase of total 11-hydroxycorticosteroids level in the blood of intact and castrated rats. Activity of protein kinase A increased in the cytosol and membrane fraction of adrenocorticocytes of intact and orchiectomized rats after estradiol influence. Activity of protein kinase C significantly raised in the cytosol and membrane fraction of adrenocortical cells in all investigated groups. Our results suggest that cAMP-dependent protein kinase A and protein kinase C mediate estradiol effects in adrenal cortex.

[Optimization of hepatoprotective therapy of viral hepatitis with consideration of neuromediatory link of pathogenesis].

AIM: To study therapeutic efficacy of hepatoprotective modalities on the experimental hepatitis model and in patients with parenteral hepatitis B and C regarding neurogenic amines and their coefficients. MATERIAL AND METHODS: 38 hepatoprotectors were screened for the highest activity in 1000 white rats with toxic hepatitis. Blood catecholamines (CA), histamine (H), serotonin (S), 11-oxycorticosteroids (11-OCS) were studied in 100 patients with acute hepatitis B and C. RESULTS: The recommended hepatoprotectors optimized treatment of hepatitis, led to rapid correction of abdominal and dyspeptic syndromes, normalization of bilirubin, alkaline phosphatase, cytolysis enzymes levels, improvement of neuromediatory balance. Six-month follow-up demonstrated improvement of biochemical indices in patients given hepatoprotectors with a confirmed action. CONCLUSION: Hepatoprotectors are necessary in pathogenetic treatment of acute hepatitis B and C.

Adrenal function in 23 children with paracoccidioidomycosis.

Adrenal involvement by Paracoccidioides brasiliensis was described at necropsies and in many clinical studies, but only in adults. Therefore, the aim of this study was to evaluate adrenal function in children with paracoccidioidomycosis. Twenty-three children with the systemic form of paracoccidioidomycosis were evaluated and divided in two Groups: Group A (n = 8) included children before treatment and Group B (n = 15) children after the end of treatment. Plasma cortisol (basal and after ACTH test), ACTH, renin activity, aldosterone, sodium and potassium were measured. They were within normal range in all cases, except for renin activity and aldosterone, which were elevated in some cases. Group A patients showed basal and post-ACTH cortisol levels significantly greater than Group B patients. The results showed that adrenal function was not compromised in these children with paracoccidioidomycosis.

[Effect of 17beta-estradiol on content of cyclic nucleotides and protein kinases A and C activity in human adrenal cortex].

The influence of 17beta-estradiol on cAMP and cGMP levels, protein kinases A and C activityand corticosteroids secretion was investigated in postoperative human adrenal cortex tissue. cAMP accumulation in adrenocorticocytes increased uiider the influence of 17beta-estradiol. In vitro estradiol raised the activities of protein kinases A and C in membrane fraction of adrenal cortex tissue. Significant increasing of steroidogenesis was observed. These data support our conclusion that cAMP dependent siganling system is involved in activation of steroidogenesis by 17beta-estradiol.

[Effect of the perturbed geomagnetic field on the metabolism of the rat connective tissue during heat exposure].

The biochemical data of the researches of the perturbed geomagnetic field influence on the metabolism of the rat's connective tissue by the heating are presented. The possibility of adrenal glands reaction modification under using the perturbed geomagnetic field after high temperature is shown.

The excretion rates of stress hormones under mental work.

The aim of the study was to assess stress on the basis of the excretion rates of stress hormones in occupational groups under mental stress. The investigation includes 293 persons, working in power engineering, education, public health and information sector. The stress hormones adrenaline, noradrenaline and 11-oxycorticosteroids (11-OCS) were followed during the working day using spectrofluorimetric methods. Very high excretion rates of adrenaline, noradrenaline and/or 11-OCS were found with leading radio editors, responsible engineers and operators in nuclear power station (NPS), teachers in secondary schools, designing engineers. In conclusion our data indicate high stress in occupational groups working under high psychological demands, high responsibility, making important managing decisions, low job control and are discussed with regard to the health risk.

Incorporation of labelled N-acylethanolamine (NAE) into rat brain regions in vivo and adaptive properties of saturated NAE under x-ray irradiation.

Regional distribution of exogenous N-palmitoylethanolamine in the rat brain was investigated in the study. Possible protective and adaptive effect of N-stearoylethanolamine under 2 Gy whole-body X-irradiation and changes of brain lipid composition were also studied. It was found that after per os administration to rats N-([9,10-3H]-palmitoyl)-ethanolamine was primarily accumulated in hypothalamus, pituitary and adrenal glands and the label amount in brain was 0.95% of the oral dose. Quantities of palmitic acid in total brain phospholipids and plasmalogen form of phosphatidylcholine were increased; free cholesterol and diacyl form of phosphatidylcholine were decreased in 2 weeks after irradiation. 11-OH-corticosteroid level in the blood of exposed rats was decreased in comparison with control animals. N-stearoylethanolamine pre-treatment prevented from increasing the plasmalogen form of phosphatidylcholine and decreasing its diacyl form and restored 11-OH-corticosteroid level in the blood of irradiated rats. Recovering of brain free cholesterol level was observed when N-stearoylethanolamine was post-treated. So, the accumulation of N-([9,10-3H]-palmitoyl)ethanolamine in brain indicates its penetration through blood-brain barrier and suggests the possible role of saturated N-acylethanolamines in brain functioning, particularly, in stress response regulation of the organism by hypothalamus-pituitary-adrenal system. N-stearoylethanolamine treatment of irradiated rats causes protective effect concerning the of irradiation induced changes in the brain lipid composition and in 11-OH-corticosteroid level and modifies phospholipid fatty acid composition.

[An ACTH-like peptide immunocortin: effect on the activity of cells from the rat adrenal cortex]. / Vliianie AKTG-podobnogo peptida immunokortina na aktivnost' kletok kory nadpochechnikov krysy.

The effect of immunocortin, an ACTH-like decapeptide VKKPGSSVKV corresponding to the 11-20 sequence of the variable part of the human IgG1 heavy chain on the content of 11-hydroxycorticosteroids (CS) in rat adrenal glands and blood serum in vivo was studied. An intramuscular injection of immunocortin at a dose of 10 microg/kg was found in an hour to induce a twofold decrease in CS content in the adrenal glands and a 1.8-fold increase in the blood serum CS content. At the same time, an immunocortin dose of 100 microg/kg exerted practically no effect on the CS content and its dose of 1000 microg/kg increased the CS content both in adrenal glands and in blood serum by 1.6 and 2.2 times, respectively. Four hours after the injection of any of the three doses of immunocortin, the CS content in adrenal glands did not differ from the control value, and after 24 h the content decreased threefold. Immunocortin was shown to be bound by the ACTH receptors in the membranes of the rat adrenal cortex with a high affinity and specificity (inhibiting the specific binding of 125I-labeled ACTH-(11-24) peptide with Ki of 1.2 nM).

Elucidation and characteristics of non-opioid beta-endorphin receptors in rat adrenal cortex.

beta-Endorphin-like decapeptide immunorphin (SLTCLVKGFY), a selective agonist of non-opioid beta-endorphin receptor, was labeled with tritium to specific activity of 24 Ci/mmol. It was used for the detection and characterization of non-opioid beta-endorphin receptors on rat adrenal cortex membranes (Kd1 = 39.6 +/- 2.0 nM, Bmax1 = 40.7 +/- 2.3 pmol/mg protein; Kd2 = 0.25 +/- 0.01 micro M, Bmax2 = 187.8 +/- 9.4 pmol/mg protein). beta-Endorphin was found to inhibit the [3H]immunorphin specific binding to membranes (Ki = 70.0 +/- 9.2 nM); naloxone, [Met5]enkephalin, and alpha- and gamma-endorphins tested in parallel were inactive. Immunorphin at concentrations of 10(-9)-10(-6) M was found to inhibit the adenylate cyclase activity in adrenocortical membranes, while intramuscular injection of immunorphin at doses of 10-100 micro g/kg was found to reduce the secretion of 11-oxycorticosteroids from the adrenals to the bloodstream.