ABSTRACT
Trypanosoma cruzi, a flagellated protozoan, is the causative agent of Chagas disease. The parasite has developed various mechanisms to get through its intricate life cycle and adapt to different evolutionary phases. T. cruzi proliferates in the insect vector's digestive tract as an epimastigote form, encountering fluctuating nutrient availability and oxidative stress caused by the digestion of red blood cells from the mammalian host blood meal. To unravel how the parasite's metabolism adapts to these changing conditions, we conducted an analysis of the chemical species present in epimastigote forms. This involved comparing cultured parasites with those subjected to nutritional deficiency or oxidative stress using untargeted metabolomics. We looked at 21 samples: seven biological copies of parasites that were actively growing, seven samples that were put in a medium without nutrients for 3 h, and seven samples that were treated with glucose oxidase for 30 min to make H2O2 continuously. Importantly, in all conditions, parasite viability was maintained when the samples were collected. Upon nutrient removal, we observed a substantial decrease in amino acids and carbohydrate metabolites, accompanied by the accumulation of fatty acids and steroids, with the predominance of inositol and sphingolipid metabolism, along with a simultaneous decrease in the levels of H2O2. In the presence of H2O2, a significant rise in components of the pentose pathway and specific amino acids such as methionine and serine occurred, along with pathways related to an increase in antioxidant species metabolism such as ribulose 5-phosphate and glyceric acid. Conversely, fatty acid and steroid levels decrease. We found no common increase in metabolites or lipids. In contrast, eight species (succinic acid, glutamic acid, valine, 2-hydroxyisocaproic acid, alanine, indolelactic acid, proline, and lanosterol) were consumed under both stresses. These findings underscore the rapid and distinct enrichment responses in amino acids, lipids, and carbohydrates required to cope with each different environmental condition. We concluded that T. cruzi presents a flexible metabolism that rapidly adapts to variable changes in the environment.
ABSTRACT
A presente pesquisa buscou investigar o efeito de diferentes situações de estresse térmico (WBGT) sobre a frequência cardíaca (FC), gasto energético (GE), perda hídrica (PH) e consumo de água (CA) em jovens atletas de voleibol. Participaram do estudo 09 indivíduos (16,5±0,9 anos) integrantes da equipe masculina juvenil de voleibol de Umuarama. As variáveis FC, GE, PH e CA foram mensuradas durante duas sessões de treinamento (S1, S2) de volume (85min) e intensidade semelhantes, porém, com diferentes situações de estresse térmico (S1: WBGT:22,62°C; S2: WBTG: 26.55°C). O estresse térmico (WBGT) do ambiente foi determinado por um termômetro de globo modelo ITWTG2000. A FC e o GE foram mensurados por meio do equipamento Sunnto Team Pod. A PH foi calculada pela diferença entre o peso corporal no início e final das sessões de treinamento. O CA foi ?ad libitum?, porém, o volume total ingerido foi calculado usando copos descartáveis de 180ml. Para análise dos dados foi utilizado o teste T pareado (amostras dependentes). O índice de significância adotado foi de p<0,05. Após análise dos dados, observou-se similar FC (S1: 135,5±16,3bpm vs. S2: 141,5±21,5bpm), GE (S1 :994,44±267,4Kcal vs. S2: 881,2±259,6Kcal), PH (S1: 0,6±0,2Kg vs. S2: 0,4±0,3Kg) e CA (S1 :1120±345mL vs. S2: 760±429mL) nas duas sessões de treinamento. Os resultados indicam que uma pequena variação no estresse térmico do ambiente não afeta de forma marcante a FC, GE, PH e CA durante o treinamento de voleibol.
This paper sought to investigate the effect of different thermal stress situations (WBTG) on heart rate (FC), energy expenditure (GE), water loss (PH) and water intake (CA) in young volleyball players. For such, 09 young male volleyball players from Umuarama Volleyball participated of this research (16.5±0.9 years). The variables FC, GE, PH and CA were measured during two training sessions (S1, S2) with similar volume (85 min) and intensity but, with different thermal stress situations (S1: WBTG: 22.62ºC and S2 WBGT: 26.55ºC). The thermal stress (WBGT) in the training environment was determined by a globe thermometer model ITWTG2000. The FC and the GE were measured by a Suunto Team Pod. PH was calculated by the difference between the body weight at the beginning and at the end of the training sessions. The CA during the training sessions was ?ad libitum? but the total volume ingested was calculated using 180-ml plastic cups. For the data analysis, the paired T test (dependent samples) was used. The significance index adopted was p <0.05. After the analysis of the data, similar FC (S1: 135.5 ±16.3bpm vs. S2: 141.5±21.5bpm), GE (S1: 994.44±267.4 Kcal vs. S2: 881.2±259.6 Kcal), PH (S1: 0.6±0.2 Kg vs. S2: 0.4±0.3 Kg) and CA (S1: 1120±345ml vs. S2: 760±429 ml) were observed in both training sessions. The results indicate that a little variation in the environmental thermal stress does not markedly affect the FC, GE, PH and CA during volleyball training sessions.
