Endogenous corticosteroids and insulin in acute inflammation

Carrageenin-induced inflammatory responses in the hindpaws of rats were quantitated by measuring: (1) alterations in volumes of the paws; and (2) alterations in concentration of dye, previously injected intravenously, which was recovered in perfusates from the paws. The inflammatory response in one paw was attenuated by previously inducing an inflammatory response in the contralateral paw. The effect was abolished by pretreatment with insulin. Indexes of adrenal activity were increased after the induction of the inflammatory response and they were not attenuated by pretreatment with insulin. Adrenal hyperactivity was characterized by increased serum corticosterone concentration, decreased adrenal ascorbic acid content, and reduced number of circulating eosinophils. It is concluded that inflammatory stimuli which lead to alterations in microvessels depend on a facilitatory effect of insulin. This effect is antagonized by glucocorticoids released in enhanced concentrations after the application of noxious stimuli. Therefore, endogenous insulin and glucocorticoids act as modulators of inflammatory responses.

Baseline and stress-induced plasma corticosterone concentrations of mice selectively bred for high voluntary wheel running

The hypothalamic-pituitary-adrenal (HPA) axis is important in regulating energy metabolism and in mediating responses to stressors, including increasing energy availability during physical exercise. In addition, glucocorticoids act directly on the central nervous system and influence behavior, including locomotor activity. To explore potential changes in the HPA axis as animals evolve higher voluntary activity levels, we characterized plasma corticosterone (CORT) concentrations and adrenal mass in four replicate lines of house mice that had been selectively bred for high voluntary wheel running (HR lines) for 34 generations and in four nonselected control (C) lines. We determined CORT concentrations under baseline conditions and immediately after exposure to a novel stressor (40 min of physical restraint) in mice that were housed without access to wheels. Resting daytime CORT concentrations were approximately twice as high in HR as in C mice for both sexes. Physical restraint increased CORT to similar concentrations in HR and C mice; consequently, the proportional response to restraint was smaller in HR than in C animals. Adrenal mass did not significantly differ between HR and C mice. Females had significantly higher baseline and postrestraint CORT concentrations and significantly larger adrenal glands than males in both HR and C lines. Replicate lines showed significant variation in body mass, length, baseline CORT concentrations, and postrestraint CORT concentrations in one or both sexes. Among lines, both body mass and length were significantly negatively correlated with baseline CORT concentrations, suggesting that CORT suppresses growth. Our results suggest that selection for increased locomotor activity has caused correlated changes in the HPA axis, resulting in higher baseline CORT concentrations and, possibly, reduced stress responsiveness and a lower growth rate. © 2007 by The University of Chicago. All rights reserved.

Different stress biomarkers sensitivity during acute treadmill running exercise in rats

The level of stress during acute or chronic exercise is important since higher levels of stress may impair homeostasis. The adrenal gland is an essential stress-responsive organ involved in the hypothalamic-pituitary-adrenal axis. The aim of the study was to analyze the sensitivity of different stress biomarkers of the adrenal gland during acute treadmill running at different intensities. Adult rats performed three 25 min running tests at velocities of 15, 20 and 25 m/min, for determination of maximum lactate steady state (MLSS). After obtaining individual MLSS animals were assigned to two groups: M, sacrificed after 25 minutes of exercise at MLSS, and AM, sacrificed after exercise at 25% above MLSS. For comparison, a control group C was sacrificed at rest. Blood corticosterone concentrations, as well, adrenal gland cholesterol and ascorbic acid concentrations were used as biomarkers. Serum corticosterone concentrations were higher after exercise in both M (1802,74±700,42) and AM (2027,96±724,94) groups when compared C group (467,11±262,12), but were not different as a function of exercise intensity. No difference in adrenal ascorbic acid (M=2,37±0,66; AM=2,11±0,50 and C=2,54±0,53) and cholesterol (M=1,04±0,12; AM=0,91±0,31 and C=1,15±0,40) levels were observed when the three groups were compared. Serum corticosterone concentrations showed to be sensitive to acute treadmill exercise intensity. On the other hand, ascorbic acid and cholesterol concentrations in adrenal were biomarkers not adequate to evaluate exercise stress in rats.

Polyethylene gel in the subcutaneous tissue of rats: Histopathologic and systemic evaluation

Purpose: To evaluate the histological and systemic response to subcutaneous injection of polyethylene gel in rats. Methods: Twenty-one white male rats were divided into 3 groups (G): G1 and G2 received subcutaneous polyethylene gel injection in the dorsal midline and were sacrificed at 30 and 60 postoperative days, respectively. G3 was not exposed to the polyethylene gel and was sacrificed after 60 days. Blood levels of lactate dehydrogenase (LDH), creatine kinase (CK), and alkaline phosphatase (ALP) were evaluated. The heart, kidney, liver, adrenal gland, injection site, and adjacent tissues were histologically examined. The results were submitted to statistical analysis. Results: There was no clinical evidence of extrusion, reduction of the injected volume, or abnormalities in the adjacent tissues. Blood levels of CK and LDH were normal and similar in all groups. ALP levels were significantly lower in G2 than in G1 and G3. The systemic organs were normal on histological examination in the 3 groups evaluated. Microscopically, the polyethylene gel was surrounded by a thin pseudocapsule formation and minimal inflammatory cell response, which decreased from G1 to G2. Conclusion: The subcutaneous injection of polyethylene gel in rats elicited minimal local inflammatory response and no systemic side effects. Copyright © 2008 Informa Healthcare USA, Inc.

Spatio-temporal distribution of fatty acid-binding protein 6 (fabp6) gene transcripts in the developing and adult zebrafish (Danio rerio)

We have determined the structure of the fatty acid-binding protein 6 (fabp6) gene and the tissue-specific distribution of its transcripts in embryos, larvae and adult zebrafish (Danio rerio). Like most members of the vertebrate FABP multigene family, the zebrafish fabp6 gene contains four exons separated by three introns. The coding region of the gene and expressed sequence tags code for a polypeptide of 131 amino acids (14 kDa, pI 6.59). The putative zebrafish Fabp6 protein shared greatest sequence identity with human FABP6 (55.3%) compared to other orthologous mammalian FABPs and paralogous zebrafish Fabps. Phylogenetic analysis showed that the zebrafish Fabp6 formed a distinct clade with the mammalian FABP6s. The zebrafish fabp6 gene was assigned to linkage group (chromosome) 21 by radiation hybrid mapping. Conserved gene synteny was evident between the zebrafish fabp6 gene on chromosome 21 and the FABP6/Fabp6 genes on human chromosome 5, rat chromosome 10 and mouse chromosome 11. Zebrafish fabp6 transcripts were first detected in the distal region of the intestine of embryos at 72 h postfertilization. This spatial distribution remained constant to 7-day-old larvae, the last stage assayed during larval development. In adult zebrafish, fabp6 transcripts were detected by RT-PCR in RNA extracted from liver, heart, intestine, ovary and kidney (most likely adrenal tissue), but not in RNA from skin, brain, gill, eye or muscle. In situ hybridization of a fabp6 riboprobe to adult zebrafish sections revealed intense hybridization signals in the adrenal homolog of the kidney and the distal region of the intestine, and to a lesser extent in ovary and liver, a transcript distribution that is similar, but not identical, to that seen for the mammalian FABP6/Fabp6 gene. © 2008 The Authors.

Ultrassonografia abdominal de cães e gatos hígidos, adultos e filhotes

Pós-graduação em Medicina Veterinária - FMVZ

Emprego da tomografia computadorizada na detecção de alterações das adrenais em doentes com tuberculose

Pós-graduação em Doenças Tropicais - FMB

Papel do zinco sobe a fertilidade e função testicular de ratos expostos ao tabaco

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação das características e medidas ultrassonográficas das glândulas adrenais de cães e gatos filhotes saudáveis

The aim of the study was to analyze and compare the ultrasound characteristics of adrenal glands between healthy puppies and kittens by establishing standards of normality and references. Fifteen healthy crossbred puppies with mean weight of 3 kg and fifteen healthy crossbred kittens with mean weight of 2 kg, aged between five and six months, participated in the study. The animals were submitted to ultrasound exam of adrenal glands for visualization of their internal characteristics. The frequency of visualization of adrenal glands was 100% in kittens. In puppies the frequency was 75% for the right gland and 100% for the left gland. The puppy's adrenal gland, both right and left, were bigger in length (1.08 ± 0.01 cm, 1.11 ± 0.01 cm) and width (0.42 ± 0.02 cm, 0.45 ± 0.01 cm) in relation to kittens' adrenal gland length (0.64 ± 0.01 cm, 0.63 ± 0.01 cm) and width (0.30 ± 0.02 cm, 0.34 ± 0.01 cm). The adrenal gland of puppies and kittens was hypoechogenic to the surrounded fat, delimited by a hyperechogenic line and without distinction of the cortical and medullar region. The ultrasound dimensions of length and width of the adrenal glands, both right and left, were the same in puppies and kittens. The right and left puppies' adrenal glands were longer and wider than the kittens' glands.

Hiperadrenocorticismo atípico em cães

The endocrine diseases, notably Cushing's disease, are of great importance from the morbid pictures that affect the canine species. Due to the imprecision of the standard tests, the HAC can be a diagnosis difficult to confirm. Often, the clinical manifestations and biochemical and hematological findings support the diagnosis of HAC, but endocrine tests are normal or inconclusive. The excessive production of ACTH may, in the adrenals, not only stimulate the increase of glucocorticoids, but also of sex hormones. In recent studies, the concentrations of sex hormones were used as parameters to check the adrenal gland function in animals with suspected Cushing's disease, suggesting that high serum concentrations of 17 hydroxyprogesterone (17OHP) and other sex steroid hormones would be the cause of the so called atypical hyperadrenocorticism

Molecular detection of Leishmania spp. in road-killed wild mammals in the Central Western area of the State of São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assistência cirúrgico-odontológica a pacientes imunodeprimidos por uso crônico de corticoides

Objective: The objective of this work, and review concepts on the physiology of hormones Adrenals to enhance pre, trans and post-operative care to dentists facing surgical, dental care of immunosuppressed patients. Literature review: The corticosteroids are among the most used drugs in medicine in recent times due to its anti-inflammatory and immunosuppressive activities, especially in transplant patients and patients with chronic autoimmune diseases. However, the continuing use of these drugs leads to a decrease in endogenous production of cortisol by the adrenal. Besides depressing the patient’s immune system, it may generate many parallel undesirable effects like blocking the production of the natural hormone of adrenal cortex, or steroid called cortisol, which may be the cause of a malfunctioning of the adrenal gland, causing hypofunction or hyperfunction of the gland. Final considerations: This fact will lead to changes in the planning of dental surgery, where it will be necessary special actions towards the patients who have this condition.

O temperamento de bovinos confinados em diferentes disponibilidades de espaço e suas relações com o desempenho e a qualidade da carcaça e da carne

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hiperadrenocorticismo em cães: revisão

Hyperadrenocorticism is a relatively common endocrinopathy in dogs, which is associated to an excessive production or administration of cortisol. The most affected breeds are Poodles, Teckels, Boxers, Boston Terriers and Beagles. The clinical signs most commonly observed are polyuria, polydipsia, polyfagia, panting, distended abdomen, endocrine alopecia, muscular weakness and lethargy. Laboratorial abnormalities include stress leukogram, increase in alkaline phosphatase and alanine aminotransferase activities, hypercholesterolemia, lipemia, hyperglycemia and hyposthenuria. The preferred essay to evaluate adrenal gland function is the low-dose dexamethasone suppression test, whereas the most used treatments include mitotane and trilostane. The objective of this paper is to review hyperadrenocorticism in dogs, because this disease is relatively common in small animal clinics and has many long-term complications.

Influence of N-methyl-D-aspartate receptors on ouabain activation of nuclear factor-kappa B in the rat hippocampus

It has been shown that ouabain (OUA) can activate the Na,K-ATPase complex and mediate intracellular signaling in the central nervous system (CNS). Inflammatory stimulus increases glutamatergic transmission, especially at N-methyl-D-aspartate (NMDA) receptors, which are usually coupled to the activation of nitric oxide synthase (NOS). Nuclear factor-kappa B (NF-kappa B) activation modulates the expression of genes involved in development, plasticity, and inflammation. The present work investigated the effects of OUA on NF-kappa B binding activity in rat hippocampus and the influence of this OUA-Na,K-ATPase signaling cascade in NMDA-mediated NF-kappa B activation. The findings presented here are the first report indicating that intrahippocampal administration of OUA, in a concentration that did not alter Na,K-ATPase or NOS activity, induced an activation of NF-kappa B, leading to increases in brain-derived neurotrophic factor (Bdnf), inducible NOS (iNos), tumor necrosis factor-alpha (Tnf-alpha), and B-cell leukemia/lymphoma 2 (Bcl2) mRNA levels. This response was not linked to any significant signs of neurodegeneration as showed via Fluoro-Jade B and Nissl stain. Intrahippocampal administration of NMDA induced NF alpha B activation and increased NOS and alpha 2/3-Na,K-ATPase activities. NMDA treatment further increased OUA-induced NF-kappa B activation, which was partially blocked by MK-801, an antagonist of NMDA receptor. These results suggest that OUA-induced NF-kappa B activation is at least in part dependent on Na,K-ATPase modulatory action of NMDA receptor in hippocampus. The interaction of these signaling pathways could be associated with biological mechanisms that may underlie the basal homeostatic state linked to the inflammatory signaling cascade in the brain. (c) 2011 Wiley Periodicals, Inc.