Laboratório de Fisiologia Cardiovascular, Departamento de Ciências Biológicas, Instituto de Ciências Biológicas, Universidade Federal de Ouro Preto, Morro do Cruzeiro, 35400000 Ouro Preto, Minas Gerais, Brazil; Programa de Pós-graduação em Ciências Biológicas - NUPEB, Universidade Federal de Ouro Preto, Campus Universitário, Morro do Cruzeiro, 35400000 Ouro Preto, Minas Gerais, Brazil.
Toxicon. 2013 Dec 15;76:343-9. doi: 10.1016/j.toxicon.2013.09.015. Epub 2013 Sep 21.
Scorpion envenoming and malnutrition are considered two important public health problems in Brazil, involving mainly children. Both these conditions are more common among the economically stratified lower income portion of the population, thus suggesting that these factors should be analyzed concomitantly. It is known that cardiorespiratory manifestations, as cardiac arrhythmias, arterial hypertension and hypotension, pulmonary edema and circulatory failure are the main "causa mortis" of scorpion envenomation. Additionally, there are evidences in the literature that deficiencies in dietary intake endanger the CNS and modify the cardiovascular homeostasis. Then, the objective of this work is to evaluate the protein malnourished effect on cardiovascular responses induced by tityustoxin (TsTX, an α-type toxin extracted from the Tityus serrulatus scorpion venom). Fischer rats (n = 20) were injected i.c.v. with TsTX and divided in control and malnorished groups, which were, respectively, submitted to a control and a low-protein diet. Arterial pressure recordings were done until death of the animals. Although both groups presented an increased mean arterial pressure after TsTX injection, this increase was smaller and delayed in malnourished rats, when compared to control rats. In addition, heart rate increased only in rats from the control group. Finally, malnourished rats had an increase in survival time (9:9/13.5 vs. 15.5:10.5/18 min; p = 0.0009). In summary, our results suggest that the protein restriction attenuates the cardiovascular manifestations resulting from TsTX action on CNS.
蝎螫伤和营养不良被认为是巴西的两个重要公共卫生问题，主要涉及儿童。这两种情况在经济上处于较低收入阶层的人群中更为常见，因此表明这些因素应该同时进行分析。众所周知，心血管表现，如心律失常、动脉高血压和低血压、肺水肿和循环衰竭是蝎螫伤的主要“死因”。此外，文献中有证据表明，膳食摄入不足会危及中枢神经系统并改变心血管稳态。因此，这项工作的目的是评估蛋白质营养不良对 tityustoxin（TsTX，从 Tityus serrulatus 蝎毒液中提取的一种α型毒素）引起的心血管反应的影响。Fischer 大鼠（n=20）经脑室内注射 TsTX，并分为对照组和营养不良组，分别给予对照饮食和低蛋白饮食。记录动脉压，直至动物死亡。尽管两组在 TsTX 注射后均出现平均动脉压升高，但与对照组相比，营养不良组的这种升高幅度较小且延迟。此外，只有对照组的大鼠心率增加。最后，营养不良组的存活时间延长（9:9/13.5 对 15.5:10.5/18 分钟；p=0.0009）。综上所述，我们的结果表明，蛋白质限制可减轻 TsTX 对中枢神经系统作用引起的心血管表现。
