الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 79 |  |  |
| | | from | 79 | | |
Abstract
The present study was aimed to evaluate of fecal and serum levels of activin - A as a biomarker for early diagnosis of UC and correlate between tissue level of activin A and its fecal and serum levels in comparison with that of calprotectin in induced murine models of ulcerative colitis. The study was carried out on a total number of 20 Wistar albino female rats (3-4 months old; weight, 200±20 g) were obtained from the experimental animal house, department of Pathology, Faculty of Veterinary Medicine, Assiut University to be used for the study. Rats were maintained in an environment with a 12/12 - light/dark cycle at 21.0±2.0˚C room temperature and 60.0±5.0% humidity. Rats were kept for 2 weeks to be acclimatized on the new environment and were fed a standard rat pellet and tap water diet, with 12 h fasting employed prior to the experiment. The experiment was performed at the experimental animal house of Forensic Medicine Department in Faculty of Veterinary Medicine at Assiut University, Egypt. Rats were randomly divided into 4 groups (5 rats each) and used for induction of short and long-term UC. Animal model of ulcerative colitis was induced using 3% dextran sodium sulphate Briefly, short term model of UC was induced using 3% DSS that was added to drinking water for six successive days. Long term model of UC was induced with 3% DSS for three cycles. Each cycle consisted of 3 days on tap water contained 3% DSS followed by 12 days on tap water without DSS. The two negative control groups received tap water without treatment for 6 days and 45 days, respectively. At the end of the experiment, rats of all groups were fasted overnight and subsequently were euthanized under complete anesthesia by Isoflurane inhalation anesthesia using DROP jar method. from each rat serum and fecal samples were collected for immunoassay of activin -A and calprotectin. Furthermore, colon tissue samples were obtained for histopathological examination and quantitative gene expression.
The results of this study could be summarized in the following points:
Physical examination of fecal matter revealed no apparent changes in short term model. However, fecal matter of long term group showed changes of consistency with increased moistening and one rat showed bloody feces.
Gross examination of GIT revealed no apparent inflammatory signs in short term group. Nevertheless, some inflammatory signs were apparent on colons of long term group animals.
Histopathological findings showed that short-term acute model of UC showed ulceration of the colon mucosa with disruption of the lining epithelium and inflammatory cell infiltration was evident in the form of macrophages and lymphocytes whereas long term model showed extensive ulceration of the colon mucosa with disruption of the epithelium and hyperplasia of goblet cells and heavy lymphocytic infiltration.
There was a highly significant increase in fecal and serum activin- A in both a short and long term UC models while there was a significant increase of fecal calprotectin only in chronic long term model of UC. Evaluation of gene expression revealed significant upregulation of activin- A in short-term model but not in long-term UC model, whereas calprotectin expression showed significant upregulation in chronic long-term but not in short-term of UC model. Interestingly, Pearson correlation coefficient revealed a strong positive correlation between serum, fecal and gene expression
of activin- A in short term and long term UC while calprotectin showed strong negative correlation between serum and fecal calprotectin but serum and gene expression of calprotectin were positively correlated in short term UC.