Compared with the 5-FU-induced diarrhea model, the castor oil-induced diarrhea model has the characteristics of faster induction of diarrhea, shorter duration of diarrhea, and more frequent watery diarrhea. These two models have different characteristics of diarrhea. We employed two types of mouse diarrhea models, the 5-FU-induced diarrhea model and the castor oil-induced diarrhea model. Experimental protocols were approved by the Jeonbuk National University Animal Care and Use Committee (JBNU 2020-047). Mice were age- and sex-matched at the onset of each experiment. Mice were maintained under a 12 h dark-light cycle at a temperature of 20-22˚C (45-70% humidity) and fed on food and water ad libitum. Specific pathogen-free BALB/c mice (6-8 weeks of age) were purchased (Damul Experimental Animal Center, Daejeon, Republic of Korea) and housed in steel wire net-covered plastic cages containing bedding chips (Damul Experimental Animal Center) (regular cage) at the Jeonbuk National University Hospital Animal Care Facility. The results can be helpful to researchers who encounter difficulties in evaluating the severity of diarrhea in experimental mouse models. More practical criteria and procedures for grading the diarrhea score on defecated stools are also proposed with clear boundaries between grades. Consequently, in this study, we aimed to propose improved methods for stool collection (paper towel methods which can collect defecated stools with little damage). In the present study, we searched the literature published in the last five years reporting the results of the mouse diarrhea score and identified the drawbacks of the previously used stool collection methods and criteria for determining the diarrhea score. Moreover, it was often difficult to determine the exact grade for the parameters employed in evaluating the diarrhea score, because of the overlapping ambiguous boundaries between grades described in many previous studies ( 2, 5, 6, 17, 22). It was also difficult to evaluate the diarrhea score on the stool stuck to the bedding chips. When we tried to collect feces during the study, we encountered difficulties in collecting intact feces by using regular mouse cages containing bedding chips, because many defecated feces were contaminated or damaged by the bedding chips or the foot and body of the moving mice. We recently evaluated the diarrhea score in a study using a mouse model of 5-fluorouracil (5-FU)-induced diarrhea ( 70). To correctly evaluate the severity of diarrhea on the stool, defecated feces should be collected without damage caused by external factors such as contamination by bedding chips or crushing by being stepped on by the mouse foot and body. Parameters frequently employed in evaluating the diarrhea score were stool consistency, stool stickiness, stool water content, stool shape, the presence of mucus or blood, diarrhea-induced fur staining, and body weight reduction ( 1- 69).Īll parameters described above, except for diarrhea-induced fur staining and body weight reduction, can only be evaluated when feces are properly collected. The diarrhea score is determined by scoring various parameters graded in 2-5 steps according to the severity of diarrhea ( 1- 69). In many studies employing mouse diarrhea models, the diarrhea score is usually determined on the defecated stool to compare the severity of diarrhea between experimental groups ( 1- 66). Mouse models have been used to study various diarrheal diseases ( 1- 69). Conclusion: These results would be helpful to researchers facing difficulties in evaluating the mouse diarrhea score. To improve the objectivity in determining diarrhea scores, practical diarrhea-scoring criteria were also proposed. When using paper towel methods, wet stools create water marks (diarrhea marks) on paper towels with strong water absorption capacity, by which diarrheal severity can be analyzed semi-quantitatively. Results: Compared to previously used methods, paper towel methods collected stools without bedding chips-induced contamination, mouse body/foot-induced damage, or sampling errors. Materials and Methods: We developed improved stool collection methods (paper towel methods) and compared them with previously used ones (stool collection using regular cages containing bedding chips or filter paper and metabolic cages). The study aimed to develop improved mouse stool collection methods and diarrhea-scoring criteria. Thus, defecated stools should be collected without damage or contamination.
Background/Aim: The mouse diarrhea score is usually determined by evaluating stool consistency and shape.
0 kommentar(er)
