Manipulation of the periovulatory sex steroidal milieu affects endometrial but not luteal gene expression in early diestrus Nelore cows

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

P-I class metalloproteinase from Bothrops moojeni venom is a post-proline cleaving peptidase with kininogenase activity: Insights into substrate selectivity and kinetic behavior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atuação da ocitocina no processo de diferenciação osteoblástica de ratas senis

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

Antidepressivo em ratos com insuficiência aórtica pode modificar a expressão gênica de ocitocina e vasopressina centrais?

Aortic regurgitation (AR) leads to a left ventricle dilation and hypertrophy in response to a chronic volume overload. It is still very frequent in developing countries, for instance Brazil, and often as secondary to rheumatic fever. Usually, chronic AR is generally well tolerated for many years, when with the heart dilated the patient searches for treatment. Bidirectional association with depression and cardiovascular disease has been described. Selective serotonin reuptake inhibitors (SSRI) are widely prescribed to treat several affective disorders, especially for cardiovascular patients since they decrease arrhythmia probability. These SSRI improves cardiac function in rats submitted to stress protocols. Preliminary study from our laboratory showed that following 4 weeks of treatment with one SSRI (paroxetine) in subchronic AR rats there was a decreased in daily sodium intake and an improvement in systolic function. An increase in the central oxytocinergic transmission may be involved in this peripheral improvement to the heart. The investigations about the mechanisms underlying this improvement are necessary. Therefore the aims of this project is investigate the effects of 4 weeks of treatment of paroxetine, a SSRI, in rats with a subchronic AR over the central central gene expression of oxytocin and vasopressin using a reverse transcription polymerase chain reaction (RT-PCR)

Sodium intake, brain c-Fos protein and gastric emptying in cell-dehydrated rats treated with methysergide into the lateral parabrachial nucleus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hydrogen peroxide centrally attenuates hyperosmolarity-induced thirst and natriuresis

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

Avaliação da atividade eletromecânica uterina em ratas por biosusceptometria AC e eletromiografia

Pós-graduação em Biologia Geral e Aplicada - IBB

Role of alfa2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

Estudo da incorporação e liberação de peptídeos hormonais utilizando membranas de látex natural como carreador

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Atuação do interferon-tau no reconhecimento materno da gestação

Maternal recognition of pregnancy is a process by which the conceptus signals its presence to the mother in order to prolong the life of the corpus luteum (CL) thus maintaining the pregnancy. This process occurs between days 15 and 19 after fertilization and is the most important biological challenge for obtaining satisfactory reproductive indices in bovine. Interferon-tau (IFN-τ) glycoprotein -secreted in the uterus by the conceptus- has a paracrine action inhibiting the expression of estrogen receptors (ESR1) and oxytocin (OXTR) in the endometrium, thus preventing the release of luteolytic pulses of prostaglandin F2 alpha (PGF2α), hormone responsible for the onset of luteolysis. IFN-τ also increases the expression of several interferon-stimulated genes (ISGs) in the uterus, CL, and blood cells. Direct endocrine action of IFN-τ on extrauterine tissues stimulates ISGs expression, which in the corpus luteum seems to be involved with luteal resistance to luteolytic action of PGF2α. This review discusses recent findings on the luteolysis mechanism in the bovine and endocrine and paracrine mechanisms such as IFN-τ during the maternal recognition of pregnancy.

Expressão gênica diferencial em tecido muscular de bovinos Nelore divergentes para qualidade de carne

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

Moxonidine into the lateral parabrachial nucleus reduces renal and hormonal responses to cell dehydration

The deactivation of the inhibitory mechanisms with injections of moxonidine (alpha(2)-adrenoceptor/imidazoline receptor agonist) into the lateral parabrachial nucleus (LPBN) increases hypertonic NaCl intake by intra- or extracellular dehydrated rats. In the present study, we investigated the changes in the urinary sodium and volume, sodium balance, and plasma vasopressin and oxytocin in rats treated with intragastric (i.g.) 2 M NaCl load (2 ml/rat) combined with injections of moxonidine into the LPBN. Male Holtzman rats (n=5-12/group) with stainless steel cannulas implanted bilaterally into LPBN were used. Bilateral injections of moxonidine (0.5 nmol/0.2 mu l) into the LPBN decreased i.g. 2 M NaCIinduced diuresis (4.6 +/- 0.7 vs. vehicle: 7.4 +/- 0.6 ml/120 min) and natriuresis (1.65 +/- 0.29 vs. vehicle: 2.53 +/- 0.17 mEq/120 min), whereas the previous injection of the alpha(2)-adrenoceptor antagonist RX 821002 (10 nmol/0.2 mu l) into the LPBN abolished the effects of moxonidline. Moxonidine injected into the LPBN reduced i.g. 2 M NaCl-induced increase in plasma oxytocin and vasopressin (14.6 +/- 2.8 and 2.2 +/- 0.3 vs. vehicle: 25.7 +/- 7 and 4.3 +/- 0.7 pg/ml, respectively). Moxonidine injected into the LPBN combined with i.g. 2 M NaCl also increased 0.3 M NaCl intake (7.5 +/- 1.7 vs. vehicle: 0.5 +/- 0.2 mEq/2 h) and produced positive sodium balance (2.3 +/- 1.4 vs. vehicle: -1.2 +/- 0.4 mEq/2 h) in rats that had access to water and NaCl. The present results show that LPBN alpha(2)-adrenoceptor activation reduces renal and hormonal responses to intracellular dehydration and increases sodium and water intake, which facilitates sodium retention and body fluid volume expansion. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Risk factors for birth-related perineal trauma: a cross-sectional study in a birth centre

Aim and objectives. To identify maternal, newborn and obstetric factors associated with birth-related perineal trauma in one independent birth centre. Background. Risk factors for birth-related perineal trauma include episiotomy, maternal age, ethnicity, parity and interventions during labour including use of oxytocin, maternal position at time of birth and infant birth weight. Understanding more about these factors could support the management of vaginal birth to prevent spontaneous perineal trauma, in line with initiatives to reduce routine use of episiotomy. Design. Cross-sectional study. Methods. Data were retrospectively collected from one independent birth centre in Brazil, during 20062009. The dependent variable (perineal trauma) was classified as: (1) intact perineum or first-degree laceration, (2) second-degree laceration and (3) episiotomy (right mediolateral or median). Results. There were 1079 births during the study period. Parity, use of oxytocin during labour, position at time of giving birth and infant birth weight were associated with second-degree lacerations and episiotomies. After adjusting for parity, oxytocin, maternal position at the expulsive stage of labour and infant birth weight influenced perineal outcomes among primiparae only. Conclusions. Although the overall rate of episiotomies in this study was low compared with national data, it was observed that younger women were most vulnerable to this intervention. In this age group in particular, the use of oxytocin as well as semi-upright positions at the time of birth was associated with second-degree lacerations and episiotomies. Relevance to clinical practice. The use of upright alternative positions for birth and avoidance of use of oxytocin could reduce the risk of perineal trauma from lacerations and need to perform episiotomy.

Cannabinoid CB1 receptor mediates glucocorticoid effects on hormone secretion induced by volume and osmotic changes

1. The present study provides the first in vivo evidence that the cannabinoid CB1 receptor mediates the effects of dexamethasone on hormone release induced by changes in circulating volume and osmolality. Male adult rats were administered with the CB1 receptor antagonist rimonabant (10 mg/Kg, p.o.), followed or not in 1 hour by dexamethasone (1 mg/Kg, i.p.). Extracellular volume expansion (EVE, 2 mL/100 g of body weight, i.v.) was performed 2 hours after dexamethasone or vehicle treatment using either isotonic (I-EVE, 0.15 mol/L) or hypertonic (H-EVE, 0.30 mol/L) NaCl solution. Five minutes after EVE, animals were decapitated and trunk blood was collected for all plasma measurements. 2. Rimonabant potentiated oxytocin (OT) secretion induced by H-EVE and completely reversed the inhibitory effects of dexamethasone in response to the same stimulus. These data suggest that glucocorticoid modulation of OT release is mediated by the CB1 receptor. 3. Although dexamethasone did not affect vasopressin (AVP) secretion induced by H-EVE, the administration of rimonabant potentiated AVP release in response to the same stimulus, supporting the hypothesis that the CB1 receptor regulates AVP secretion independently of glucocorticoid-mediated signalling. 4. Dexamethasone alone did not affect atrial natriuretic peptide (ANP) release stimulated by I-EVE or H-EVE. However, pretreatment with rimonabant potentiated ANP secretion induced by H-EVE, suggesting a possible role for the CB1 receptor in the control of peripheral factors that modulate cardiovascular function. 5. Rimonabant also reversed the inhibitory effects of dexamethasone on H-EVE-induced corticosterone secretion, reinforcing the hypothesis that the CB1 receptor may be involved in the negative feedback exerted by glucocorticoids on the activity of the hypothalamicpituitaryadrenal axis. 6. Collectively, the results of the present study indicate that the CB1 receptor modulates neurohypophyseal hormone secretion and systemic factors, such as corticosterone and ANP, thus participating in homeostatic responses to altered extracellular volume and plasma tonicity.

Resultados maternos e neonatais em centro de parto normal peri-hospitalar e hospital

OBJETIVO: Comparar os resultados maternos e neonatais em mulheres de baixo risco atendidas em centro de parto normal peri-hospitalar e hospital. MÉTODOS: Estudo transversal com amostra representativa de mulheres de baixo risco atendidas em São Paulo, SP, de 2003 a 2006. Foram incluídas 991 mulheres que tiveram o parto no centro de parto normal e 325 que deram à luz no hospital. Os dados foram obtidos dos prontuários. A análise comparativa foi realizada para o total de mulheres e estratifi cada segundo a paridade. Foram aplicados os testes qui-quadrado e exato de Fisher. RESULTADOS: Houve distribuição homogênea das mulheres segundo a paridade (45,4% nulíparas e 54,6% mulheres com um ou mais partos anteriores). Foram encontradas diferenças estatisticamente signifi cantes em relação às seguintes intervenções: amniotomia (mais freqüente entre nulíparas do hospital); utilização de ocitocina no trabalho de parto e utilização de analgésico no pós-parto (mais freqüentes no hospital entre as mulheres de todas as paridades). A taxa de episiotomia foi maior entre as nulíparas, tanto no centro de parto como no hospital. Houve maior freqüência de intervenções com o neonato no hospital: aspiração das vias aéreas superiores, aspiração gástrica, lavagem gástrica, oxigênio por máscara aberta. Também ocorreram com mais freqüência no hospital bossa serossanguínea, desconforto respiratório e internação na unidade neonatal. Não houve diferença nos valores de Apgar no quinto minuto nem casos de morte materna ou perinatal. CONCLUSÕES: A assistência no centro de parto normal foi realizada com menos intervenções e com resultados maternos e neonatais semelhantes aos do hospital.