Avaliação cardiovascular e do tempo de mergulho em Lithobates catesbeianus após a manipulação de gases intrapulmonares

O objetivo desse estudo foi avaliar o efeito da administração de gases intrapulmonares sobre os parâmetros cardiovasculares e o tempo de submersão voluntária em rã (Lithobates catesbeianus). A importância de estudos como este é ampliar o conhecimento sobre o controle e comportamento no mergulho de anfíbios. Os experimentos foram iniciados após a L. catesbeianus ser mantida no laboratório por, no mínimo, 24 horas. Foram medidas pressão arterial média (PAM, mmHg), pressão sistólica (Psis, mmHg), pressão diastólica (Pdis, mmHg), pressão de pulso (mmHg), freqüência cardíaca (FC, bpm) e tempo de submersão voluntária. O período de emersão, submersão e pós-submersão previamente à administração dos gases intrapulmonares foram utilizados como controle. Nas submersões subseqüentesforam administrados os gases: A) mistura normóxica (21% O2 / 0,3% CO2/ N2 balanço; B) mistura hipóxica e hipercapnica (14% O2 / 7% CO2/ N2 balanço); C) gás hiperóxico (100% O2) e D) 100% N2. Dos parâmetros cardiovasculares analisados, somente a FC alterou, diminuindo em torno de 20% na submersão, no entanto essa redução ocorreu antes da administração dos gases intrapulmonares. Foi observado aumento significativo do tempo de mergulho após a administração do gás hiperóxico. Pode-se concluir dos nossos resultados que o tempo de mergulho voluntário em L. catesbeianus pode ser longo se for alta a tensão de O2 pulmonar

Antinociceptive effect of extract of Emilia sonchifolia in mice

AbstractAim of the studyEmilia sonchifolia (L.) DC. (Asteraceae) is a medicinal plant traditionally used in Brazilian folk medicine to treat asthma, fever, cuts, wounds and rheumatism. This study was conducted to establish the antinociceptive properties of hydroethanolic extract from aerial parts of Emilia sonchifolia in mice using chemical and thermal models of nociception.Materials and methodsTo evaluate the antinociceptive effect of Emilia sonchifolia hydroethanolic extract (EsHE) administered by oral route, peripheral (acetic acid-induced abdominal writhing and formalin), spinal (tail flick) and supra-spinal (hot plate) behavioral models of acute pain were used. High-performance liquid chromatography (HPLC) was used to determine the fingerprint chromatogram of the EsHE.ResultsThe EsHE at test doses of 100 and 300mg/kg, p.o. clearly demonstrated antinociceptive activity in all tests. The extract had a stronger antinociceptive effect than morphine. Administration of the opioid receptor antagonist, naloxone, completely inhibited the antinociceptive effect induced by EsHE (100mg/kg). The presence of phenolic compounds in the extract of Emilia sonchifolia was confirmed using HPLC.ConclusionThe extract of Emilia sonchifolia markedly exhibits opioid-mediated anti-nociceptive activity action in mice. Thus, may be useful in the treatment of inflammatory hyperalgesic disorders, which supports previous claims of its traditional use

Effects of different nutritional support on lung mechanics and remodelling in undernourished rats

This study investigated the impact of three different oral nutritional support regimens on lung mechanics and remodelling in young undernourished Wistar rats. In the nutritionally deprived group, rats received one-third of their usual daily food consumption for 4 weeks. Undernourished rats were divided into three groups receiving a balanced, glutamine-supplemented, or long-chain triglyceride-supplemented diet for 4 weeks. In the two control groups, rats received food ad libitum for 4 (C4) or 8 weeks. Lung viscoelastic pressure and static elastance were higher in undernourished compared to C4 rats. After refeeding, lung mechanical data remained altered except for the glutamine-supplemented group. Undernutrition led to a reduced amount of elastic and collagen fibres in the alveolar septa. Elastic fibre content returned to control with balanced and glutamine-supplemented diets, but increased with long-chain triglyceride-supplemented diet. The amount of collagen fibre augmented independent of nutritional support. In conclusion, glutamine-supplemented diet is better at reducing morphofunctional changes than other diets after 4 weeks of refeeding. (c) 2007 Elsevier B.V. All rights reserved