Teores de cobre, ferro, manganês e zinco no fígado e pâncreas de caprinos semi-confinados e confinados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphofunctional changes in Leydig cells throughout the continuous spermatogenesis of the freshwater teleost fish, Serrasalmus spilopleura (Characiformes, Characidae): an ultrastructural and enzyme study

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

ENDOCRINE INTERACTION BETWEEN ZINC AND PROLACTIN - AN INTERPRETATIVE REVIEW

Zinc plays a very important role in animal and human metabolism. Nowadays, it is one of the most extensively studied trace element, since its sphere of action has been demonstrated to be very broad. From the biochemical standpoint, it controls more than 300 different enzymes, many of them involved with intermediary metabolism, DNA and RNA synthesis, gene expression, and immunocompetence. It also plays a significant role in hormonal homeostasis, since it can interact with almost all hormones. Zn2+ is closely related to the thyroid and steroid hormones, insulin, parathormone, and pituitary hormones, particularly prolactin (PRL). Zn2+ can inhibit PRL secretion within a range of physiologically and pharmacologically relevant concentrations. This property has raised the possibility of clinical applications of zinc. In this article, we review the Literature on the subject in an attempt to provide a comprehensible general view.

Midazolam and ketamine induction before halothane anaesthesia in ponies: cardiorespiratory, endocrine and metabolic changes

Six Welsh gelding ponies were premedicated with 0.03 mg/kg of acepromazine intravenously (i.v.) prior to induction of anaesthesia with midazolam at 0.2 mg/kg and ketamine at 2 mg/kg i.v.. Anaesthesia was maintained for 2 h using 1.2% halothane concentration in oxygen. Heart rate, electrocardiograph (EGG), arterial blood pressure, respiratory rate, blood gases, temperature, haematocrit, plasma arginine vasopressin (AVP), dynorphin, beta-endorphin, adrenocorticotropic hormone (ACTH), cortisol, dopamine, noradrenaline, adrenaline, glucose and lactate concentrations were measured before and after premedication, immediately after induction, every 20 min during anaesthesia, and at 20 and 120 min after disconnection. Induction was rapid, excitement-free and good muscle relaxation was observed. There were no changes in heart and respiratory rates, Decrease in temperature, hyperoxia and respiratory acidosis developed during anaesthesia and slight hypotension was observed (minimum value 76 +/- 10 mm Hg at 40 mins), No changes were observed in dynorphin, beta-endorphin, ACTH, catecholamines and glucose, Plasma cortisol concentration increased from 220 +/- 17 basal to 354 +/- 22 nmol/L at 120 min during anaesthesia; plasma AVP concentration increased from 3 +/- 1 basal to 346 +/- 64 pmol/L at 100 min during anaesthesia and plasma lactate concentration increased from 1.22 +/- 0.08 basal to 1.76 +/- 0.13 mmol/L at 80 min during anaesthesia, Recovery was rapid and uneventful with ponies taking 46 +/- 6 min to stand. When midazolam/ketamine was compared with thiopentone or detomidine/ketamine for induction before halothane anaesthesia using an otherwise similar protocol in the same ponies, it caused slightly more respiratory depression, but less hypotension. Additionally, midazolam reduced the hormonal stress response commonly observed during halothane anaesthesia and appears to have a good potential for use in horses.

PARTICIPATION OF OPIOID RECEPTORS IN THE MODULATION OF THE ANALGESIC RESPONSE BY ADRENAL AND GONADAL GLANDS

The involvement of opioid receptors in the analgesic response was evaluated by the tail-immersion test in simultaneously adrenalectomized and ovariectomized female Wistar rats (210-250 g). The reaction time (mean +/- SEM) for tail withdrawal from hot water decreased significantly 2 weeks after surgery (3.52 +/- 0.20 s) when compared to intact animals (6.09 +/- 0.23 s). Hormonal replacement with dexamethasone (50-mu-g/day) did not affect reaction time (3.38 +/- 0.19 s). However, this response was restored by combined adrenal and gonadal steroid substitution (estradiol 5-mu-g/day and progesterone 1.5-mu-g 6 h before the tests) therapy (5.11 +/- 0.45 s in animals treated with dexamethasone plus estradiol and 5.04 +/- 0.43 s in animals treated with dexamethasone plus estradiol plus progesterone). Naloxone (2 mg/kg) decreased the reaction time of animals treated with adrenal and gonadal steroids (5.11 +/- 0.45 vs 4.15 +/- 0.44 s and 5.04 +/- 0.43 vs 3.87 +/- 0.28 s, respectively, before and after naloxone) but failed to decrease it in rats treated with dexamethasone only (3.88 +/- 0.18 vs 4.34 +/- 0.25 s, before and after naloxone). These observations indicate that gonadal steroids are the most important steroid factors involved in the reaction time to tail immersion in hot water and confirm other reports that the opioid pathways modulating the neuronal circuitry require the presence of these hormones.

Myxedema ascites with elevated serum CA 125 concentration

We report a case of myxedema ascites and markedly elevated serum CA 125 concentration. The cause of ascites and elevated tumor markers in hypothyroidism remains unknown. Diagnosis was characterized by no evidence of malignancy seen by transvaginal ultrasonography or abdominal computed tomography and ascites resolution with serum CA 125 normalization after adequate hormonal treatment. Our data suggest that hypothyroidism should be considered in patients with ascites and elevated serum CA 125.

Cellular recruitment and cytokine generation in a rat model of allergic lung inflammation are differentially modulated by progesterone and estradiol

We evaluated the role of estradiol and progesterone in allergic lung inflammation. Rats were ovariectomized (Ovx) and, 7 days later, were sensitized with ovalbumin (OA) and challenged after 2 wk with inhaled OA; experiments were performed 1 day thereafter. Ovx-allergic rats showed reduced cell recruitment into the bronchoalveolar lavage (BAL) fluid relative to sham-Ovx allergic rats, as was observed in intact allergic rats treated with ICI-182,780. Estradiol increased the number of cells in the BAL of Ovx-allergic rats, whereas progesterone induced an additional reduction. Cells of BAL and bone marrow (BM) of Ovx-allergic rats released elevated amounts of IL-10 and reduced IL-1 beta and TNF-alpha. BM cells of Ovx-allergic rats released increased amounts of IL-10 and lower amounts of IL-4. Estradiol treatment of Ovx-allergic rats decreased the release of IL-10 but increased that of IL-4 by BM cells. Estradiol also caused an increased release of IL-1 beta and TNF-alpha by BAL cells. Progesterone significantly increased the release of IL-10, IL-1 beta, and TNF-alpha by BAL cells and augmented that of IL-4 by BM cells. Degranulation of bronchial mast cells from Ovx rats was reduced after in vitro challenge, an effect reverted by estradiol but not by progesterone. We suggest that the serum estradiol-to-progesterone ratio might drive cellular recruitment, modulating the pulmonary allergy and profile of release of anti-inflammatory or inflammatory cytokines. The existence of such dual hormonal effects suggests that the hormone therapy of asthmatic postmenopausal women and of those suffering of premenstrual asthma should take into account the possibility of worsening the pulmonary conditions.

THE ESSENTIAL ROLE OF ZINC IN GROWTH

Zinc is known to play a relevant role in growth and development. The basic mechanisms of action of this trace element are intimately linked to the structure and action of countless enzymes involved in many different metabolic processes. In this respect, when zinc specifically acts on cartilage growth it is involved in multiple enzymatic reactions which make this a multifactorial event. Thus, we may divide the actions of zinc into three distinct types: 1) action on taste and smell acuity, appetite regulation, and food consumption and regulation; 2) action on DNA and RNA synthesis stimulating a) cell replication and differentiation of chondrocytes, osteoblasts and fibroblasts; b) cell transcription culminating in the synthesis of somatomedin-C (liver), alkaline phosphatase, collagen and osteocalcin (bone), and c) protein, carbohydrate and lipid metabolism, that is intimately related to the mechanisms of smell, taste, appetite, and food consumption and utilization; 3) action on hormonal mediation by participating in a) GH synthesis and secretion in somatomammotroph cells, b) the action of GH on liver somatomedin-C production, and c) somatomedin-C activation in bone cartilage. In addition to these multiple functions, zinc also interacts with other hormones somehow related to bone growth such as testosterone, thyroid hormones, insulin, and vitamin D-3.On the basis of the above considerations, we conclude that the integration of these mechanisms contributes to the perfect physiological functioning of bone. Tn the presence of zinc deficiency, this homeostasis is impaired, causing the weight-height deficiency detected in several species studied, the human species in particular.

A morphometric ultrastructural study of the seminal vesicle of rats submitted to experimental chronic alcoholism

The effects of chronic alcohol ingestion on the secretory epithelium of the seminal vesicle were studied in rats (Rattus norvegicus). Male adult albino Wistar rats were divided into two groups: alcoholic and control. Tips of the seminal vesicle were removed and prepared for light and electron microscopy. Ultrastructural observations on the epithelial cells of the seminal vesicle showed reduced epithelial cell size, decreased apical secretory vacuoles, irregularly shaped nuclei with deep infoldings, increased lipid droplets and dense bodies, a small number of microvilli covering the cell surface, and signs of degeneration. In addition to the hormonal effects, alcohol may act on the secretory epithelium of the seminal vesicle.

Benefits of soy germ isoflavones in postmenopausal women with contraindication for conventional hormone replacement therapy

Objective: To evaluate the effects of isoflavones on vasomotor symptoms and blood lipids in postmenopausal women with contraindication for conventional hormone replacement therapy (HRT). Methods: This prospective, double-blind and placebo-controlled study included 50 postmenopausal women randomly divided into two groups: 25 women on soy germ isoflavones (60 mg per day, capsules) and 25 women on placebo. Inclusion criteria included: non-vegetarian, non-asian women whose last menstruation dated at least 12 months prior to the beginning of the study, With FSH > 40 mIU/ml, hot flushes and contraindication for HRT, not using tamoxifen or antibiotic and no disease of the gastrointestinal tract. For 6 months, the Kupperman menopausal index (KMI), the vaginal cytological maturation value (MV) and both hormonal and lipid profiles were assessed. The t-test and analysis of variance (ANOVA) were employed to compare the two groups. Results: In both groups, a decreased KI rate was observed. However, isoflavone was significantly superior to placebo in reducing hot flushes (44% versus 10%, respectively) (P < 0.05). After 6 months, the isoflavone group showed increased estradiol levels with unchanged FSH, LH, and vaginal cytology, and a reduction of 11.8% in LDL and an increase of 27.3% in HDL (P < 0.05). In the placebo group, just a reduction in MV was observed after 6 months (P < 0.05). Conclusions: Soy germ isoflavone exerted favorable effects on vasomotor symptoms and lipid profile, showing itself to be an interesting alternative therapy for the postmenopausal women with contraindication for conventional HRT. (C) 2003 Elsevier B.V.. All rights reserved.

Self-medication in children and adolescents

Objective: To determine the prevalence of self-medication in children and adolescents in the municipalities of Limeira and Piracicaba, state of S (a) over tildeo Paulo, and to correlate results with sociodemographic indicators and with the use of health care services (public or private).Methods: Descriptive population-based study of a simple random sample from the two municipalities, comprised of 772 inhabitants from 85 urban census sectors selected through cluster sampling. Inclusion criteria: age <= 18 years; interview with one parent/tutor; consumption of at least one drug in the previous 15 days. Subjects were divided into two study groups according to their pattern of drug use: self-medication (lay advice) and medical prescription. Linear association tests, descriptive analysis of variables and multiple logistic regression tests were carried out to analyze data.Results: the prevalence of self-medication was 56.6%. Mothers (51%) and drugstore employees (20.1%) were most frequently responsible for self-medication. The main groups of self-prescribed drugs were: analgesic/antipyretic and non-hormonal anti-inflammatory drugs (52.9%); drugs acting on the respiratory tract (15.4%) and gastrointestinal drugs (9.6%); and systemic antibiotics (8.6%). The situation that most commonly motivated self-medication were respiratory diseases (17.2%), fever (15%), and headache (14%). Subjects in the age group of 7-18 years (odds ratio = 2.81) and public health care users (odds ratio = 1.52) showed increased risk for self-medication.Conclusions: the prevalence of self-medication in children and adolescents was high, which reinforces the need for public health interventions aiming at preventing this practice.

Signaling path of the action of AVP on distal K+ secretion

Background. Previous studies from our laboratory have shown that luminal perfusion with arginine vasopressin (AVP) stimulates distal tubule secretory potassium flux (J(K)) via V1 receptors (Am J Physiol 278: F809- F816, 2000). In the present work, we investigate the cell signaling mechanism of this process.Methods. In vivo stationary microperfusion was performed in rat cortical distal tubules and luminal K was measured using double K+ resin/reference microelectrodes.Results. In control conditions, J(K) was 0.71 +/- 0.05 nmol. cm(-2).second(-1); this process was inhibited (14%) by 10(-5) mol/L 8-bromo-cyclic adenosine monophosphate (cAMP), and increased by 35% with 10(-8) mol/L phorbol ester [phorbol 12-myristate 13-acetate (PMA), which activates protein kinase C (PKC)]. During luminal perfusion with 10(-11) mol/L AVP, J(K) increased to 0.88 +/- 0.08 nmol. cm(-2).seconds(-1). In the presence of 10(-11) mol/L AVP, J(K) was not affected by 10(-4) mol/L H89, a blocker of protein kinase A (PKA), but was inhibited (45%) by 10(-5) mol/L staurosporine, an inhibitor of PKC, and by 41% during perfusion with 5 x 10(-5) mol/L of the cell Ca2+ chelator bis (2-aminophenoxy) ethane-tetraacetic acid (BAPTA). In order to study the role of Ca2+-dependent K channels in the luminal hormonal action, the tubules were perfused with 5 mmol/L tetraethylammonium chloride (TEA) or 10(-7) mol/L iberiotoxin, in the presence of AVP, and JK was significantly reduced by both agents. Iberiotoxin reduced AVP-stimulated J(K) by 36.4%, and AVP-independent J(K) (after blocking V1 receptors) by only 16%.Conclusion. The results suggest that the luminal V1-receptor effect of AVP on J(K) was mediated by the phospholipase C (PLC)/ Ca2+/PKC signaling path and not by adenylate cyclase/cAMP/PKA, therefore probably acting on maxi-potassium channels.

Concentrações séricas de progesterona e metabólitos lipídicos em cabras mestiças alimentadas com dietas hiperlipídicas durante o ciclo estral

The serum concentration of progesterone and lipidics metabolites were studied using tallow as lipidic suplementation during the estrous cycle of 32 crossbred goats, with average age and weight of five months and 25 kg. The goats were randomlly allocated in four treatments as described: treatment 1, restricted intake; treatment 2, full feed; treatments 3 and 4, hiperlipidics diets with 2.5% and 5.0% of tallow, respectively. The female goats under restricted intake, showed the small serum progesterone level (P<0.05) at 0, 3, 6, 9 and 12 days of the estrous cycle, while the ones under hiperlipidics diets, treatments 3 and 4, showed greater levels. The same results were found for serum levels of cholesterol and HDL in the estrous cycle days 6, 9 and 21, and 12, 15 and 21, respectively, that is, the females under restricted diet showed the small level and the ones treated with hiperlipidics diets, the highest. The hiperlipidics diets were important factor in altering the serum cholesterol and HDL levels, showing that the lipidic metabolism may be effective in cyclic luteal progesterone production in the puberal female goats.

Efficacy of florfenicol and intravenous fluid therapy for treatment of experimental salmonellosis in newborn calves

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

Protein diets promote the maturation of oocytes and spawning of Piaractus mesopotamicus kept in cages

The objective of this study was to evaluate the effects of balanced diets on the maturation of oocytes and the reproductive performance of P. mesopotamicus in cages. A completely random design with 224 fish in 16 cages measuring 5 m(3) was employed for this purpose. The treatments consisted of diets containing 18, 24, 30, and 36% crude protein (CP) provided ad libitum. The external and internal morphological characteristics of the specimens were examined, as well as: the position of the germinal vesicle, the distribution of oocyte diameters, the fertilization and hatching rates, the number of oocytes released, the total number of oocytes, the remaining weight and total weight of the ovaries, the gonadosomatic index, the condition factor (K), and the histology of the oocytes and ovaries post-spawning and during ovarian regression. The diameters of the oocytes collected before the first hormonal application displayed a unimodal distribution for the lowest protein content and a polymodal distribution for the other treatments. A similar situation was seen during spawning. The lowest fertilization and hatching rates were found as a consequence of the treatment with 30% CP (P < 0.05). The greatest hatching rate occurred in the females fed 18% CP. The greatest total oocyte weight was found in the specimens that received between 30 and 36% CP. The lowest K index was found in the females fed 36% CP. In conclusion, a diet containing 18% CP satisfies the reproductive requirements of females adapted to this system.