背景:关于查加斯病的研究仍然使用几种动物和大鼠,由于大小和易感性,许多作者更喜欢。
目的:建立克氏锥虫Y株接种大鼠巨结肠的实验模型。
方法:将30只雄性Wistar大鼠分为三组,分别接种不同的接种剂:A组:600000,B组:1000000和C组:1500000克氏锥虫。在零接种时间(T0)和接种后60天(T60)对动物进行肌内镇静,进行钡灌肠,以评估在获得的测量的比较研究不同部分的结肠扩张,使用数字卡尺。通过在接种后18天从动物的尾部收集的血液涂片观察血液形式,进行感染的证据。
结果:比较接种后T60天感染T0的60,0000色素动物的肠道直径,在近端之间观察到明显的扩张,内侧段和远端段(p<0.01),说明巨结肠模型的建立。此外,比较不同节段之间的肠直径,在感染的T0和接种后的T60中,观察到显著的改变(p<0.05)。
结论:所提出的模型可能用于体内研究由于T.cruzi感染引起的改变和结肠功能改变。此外,在结肠中表现出的变化与接种物的大小不成正比,但是在动物被感染的时候,因为接种了60,0000种血液的动物是表现出最显著变化的动物。
BACKGROUND: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors.
OBJECTIVE: To develop an experimental model of
megacolon in rats inoculated with the strain Y of Trypanosoma cruzi.
METHODS: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative
study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal\'s tail 18 days after inoculation with observation of blood forms.
RESULTS: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the
megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05).
CONCLUSIONS: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.