Maintenance enteral electrolyte solutions for neonatal calves: sodium acetate and osmolarity effects / Soluções eletrolíticas enterais de manutenção para bezerros neonatos: efeitos do acetato de sódio e da osmolaridade

The use of hypotonic electrolytic solutions in enteral fluid therapy is still understudied in calves. The objective of the present study was to evaluate the effects of maintenance enteral electrolytic solutions with different concentrations of sodium acetate and different osmolarities in calves. For this, 18 Holstein calves, six male and 12 female, 20 days old and weighing around 52kg, were used. The animals were randomly divided into three groups and each group received one of the treatments. The three electrolytic solutions contained the same components in different concentrations, resulting in a hyposmotic, an isosmotic and a hyperosmotic solution. Each animal was maintained in enteral fluid therapy for 12 hours with infusion rate of 15mL kg-1 h-1. Abdominal circumference, body weight, feces consistency, glucose and plasma lactate, pH, pCO2, HCO- 3 and BE were measured at the following times: T0h, T6h, T12h and T24h. The hyposmotic solution did not generate the onset of diarrhea, while the isosmotic and the hyperosmotic did. Regardless of the dose used, acetate did not cause metabolic alkalosis in the evaluated animals. The results suggest that the use of hyposmotic solution in diarrheic calves, dehydrated and without metabolic acidosis, may be clinically important.(AU)

O uso de soluções eletrolíticas hipotônicas na hidratação enteral ainda é pouco estudado em bezerros. O objetivo do presente estudo foi avaliar os efeitos de soluções eletrolíticas enterais de manutenção com diferentes concentrações de acetato de sódio e diferentes osmolaridades em bezerros. Para isso, foram utilizados 18 bezerros, seis machos e 12 fêmeas, holandeses, com 20 dias de nascidos e pesando por volta dos 52kg. Os animais foram divididos aleatoriamente em três grupos e cada grupo recebeu um dos tratamentos. As três soluções eletrolíticas continham os mesmos componentes, mas em diferentes concentrações, resultando em uma solução hiposmótica, uma isosmótica e uma hiperosmótica. Cada animal foi mantido em hidratação enteral durante 12 horas com taxa de infusão de 15mL kg-1h-1. Foram aferidos perímetro abdominal, peso corporal, consistência das fezes, glicose e lactato plasmático, pH, pCO2, HCO- 3 e excesso de base nos seguintes tempos: T0h, T6h, T12h e T24h. A solução hiposmótica não gerou aparecimento de diarreia, enquanto a isosmótica e a hiperosmótica geraram. Independentemente da dose utilizada, o acetato não causou alcalose metabólica nos animais avaliados. Os resultados sugerem que o uso da solução hiposmótica em bezerros diarreicos, desidratados e sem acidose metabólica, pode ser clinicamente importante.(AU)

Enteral electrolyte solutions with different osmolarities administered in a continuous flow in newborn calves / Soluções eletrolíticas enteral com diferentes osmolaridade administradas em fluxo contínuo em bezerros recém-nascidos

ABSTRACT: This study compared the effects of enteral electrolyte solutions with different osmolarities in Holstein cattle. Eighteen newborn calves were evenly divided into three groups and administered the following treatments: hypotonic electrolyte solution (ESHYPO) containing 4g NaCl, 0.5g KCl, 1g sodium acetate, and 7.5g dextrose diluted in 1,000mL water; isotonic electrolyte solution (ESISO) containing 5g NaCl, 1g KCl, 2g sodium acetate, and 10g dextrose diluted in 1,000mL water; and hypertonic electrolyte solution (ESHYPER) containing 6g NaCl, 1g KCl, 3g sodium acetate, and 15g dextrose diluted in 1,000mL water. Solutions were administered at a rate of 15mL kg-1hr-1 for 12 hours in a continuous flow. All three solutions increased the concentration of plasma sodium, but ESHYPO did not alter the serum osmolarity. Both ESISO and ESHYPO resulted in an increase in volemia.

RESUMO: O presente estudo comparou os efeitos de soluções de eletrolíticas enterais com diferentes osmolaridades administradas em fluxo contínuo. Dezoito animais foram divididos em três grupos: Solução eletrolítica hipotônica (SEHIPO) contendo 4g de NaCl; 0,5g de KCl; 1g de acetato de sódio; 7,5g de dextrose diluídos em 1.000mL de água; Solução eletrolítica isotônica (SEISO) contendo 5g de NaCl; 1g de KCl; 2g de acetato de sódio; 10g de dextrose diluídos em 1.000mL de água; A solução eletrolítica hipertônica (SEHIPER) contendo 6g de NaCl; 1g de KCl; 3g de acetato de sódio; 15g de dextrose diluídos em 1.000mL de água. As soluções foram administradas na dose de 15mLkg-126h-1 durante 12 horas. Os tratamentos SEHIPO, SEISO e SEHIPER aumentaram a concentração plasmática de sódio, contudo apenas a SEHIPO não ocasionou alteração na osmolaridade sérica. As SEHIPO e SEISO aumentaram a volemia.

Cytotoxic, Thrombolytic and Membrane Stabilizing Activities of Swietenia mahagoni (L.) Jacq. Flower Extract.

Aims: To investigate cytotoxic, thrombolytic and membrane stabilizing activities of methanol extract and its different Kupchan partitionates of flowers of Swietenia mahagoni. Study Design: Evaluation of cytotoxic activity using brine shrimp nauplii, thrombolytic and membrane stabilizing activities on human RBCs. Place and Duration of Study: Phytochemical Research Laboratory, Department of Pharmacy, School of Health Science, State University of Bangladesh, from April to September, 2013. Methodology: The eggs of brine shrimp nauplii were hatched in artificial sea water for 24 hours. Cytotoxic activity was determined by measuring the percentage of their mortality after application of different partitionates to them. Human RBCs were obtained from 3 healthy volunteers. Thrombolytic activity was calculated by weighing the clot before and after addition of different partitionates while membrane stabilizing activity was evaluated in terms of inhibition of percentage of haemolysis of RBCs by measuring optical density in both hypotonic and heat induced conditions. Results: The highest cytotoxic activity was achieved with the crude methanol extract (LC50 = 0.10±0.01 mg/ml) among the partitionates while vincristine sulfate, the positive control, achieved an LC50 value of 0.40±0.02 mg/ml. While investigating thrombolytic activity, the petroleum ether soluble fraction achieved the highest clot lysis activity (34.30±0.78%) compared to the standard streptokinase (70.27±1.26%). While determining the membrane stabilizing activity, in hypotonic solution induced condition, the crude methanol extract inhibited 84.71±3.25% haemolysis of RBCs whereas in heat induced condition, the aqueous soluble fraction inhibited 86.30±4.98% haemolysis of human RBCs. Here, acetyl salicylic acid (0.01mg/ml) used as reference standard showed 71.91±2.29% and 45.45±4.87% inhibition of haemolysis of human RBCs in hypotonic solution and heat induced conditions, respectively. Conclusion: From our investigation, it can be suggested that, the flower extractives can further be studied extensively to find out their efficacy.

Membrane stretch increases the activity of Ca(2+)-activated K+ channels in rabbit coronary vascular smooth muscles

It has been proposed that Ca(2+)-activated K+ channels play an essential role in maintaining vascular tone during stretch of blood vessel. However, the underlying mechanism of stretch-induced change of Ca(2+)-activated K+ channel activities are still unknown. The present experiment was designed to investigate the effect of membrane stretch on these channels whose activity was measured from rabbit coronary smooth muscle cells using a patch clamp technique. Ca(2+)-activated K+ channel were identified by their Ca2+ and voltage dependencies and its large conductances as in other preparations. Perfusion of cells with a hypotonic solution, which mimics stretching the cell membrane by making a cell swelling, produced an increase in channel activity in cell-attached patch mode. The similar increase was observed when negative pressure was applied into the patch pipette for stretching the cell membrane within a patch area. In inside-out patch, stretch still increased channel activity even under the conditions which exclude the possible involvement of secondary messengers, or of transmembrane Ca2+ influx via stretch-activated cation channels. Pretreatment of arachidonic acid or albumin showed no effect on stretch-induced channel activation, excluding the possibility of fatty acids mediated channel activation during membrane stretch. These results indicate that the stretch may directly increase the activity of Ca(2+)-activated K+ channels in our experimental condition.