Abstract Purpose: To analyze the muscle changes with high-intensity aerobic training (HIAT) in an animal model of renal disease (RD). Methods: Twenty one adult Wistar rats were divided into 3 groups: healthy sedentary (HS), RD sedentary (RDS), RD aerobic training (RDAT). RDS and RDAT were subjected to unilateral renal ischemia-reperfusion (10 min) and 21days after that, RDAT was subjected to 6 weeks HIAT (swimming). Serum creatinine (Cr) and muscle morphometry (cross-sectional area = CSA) of gastrocnemius were analyzed. Results: Cr was higher (p = 0.0053) in RDS (0.82 ± 0.04) than in the others (RDAT 0.55 ± 0.04; HS 0.55 ± 0.04). Morphometric analysis (class interval of CSA in μm2/absolute frequency of muscle fibers in each class) indicated that 50th percentile occurred in: HS 7th class (3000.00-3499.00/515), RDS, 8th class (3500.00-3999.00/484), RDAT 5th class (2000.00-2499.00/856). CSA of largest fibers in RDS, RDAT, HS was 9953.00 μm2, 9969.00 μm2,11228.00 μm2, respectively. High frequency of fibers with lower CSA occurred in 4th, 5th, 6th and 7th class in RDA, absence of fibers into 22nd, 23rd classes (RDS and RDAT). Conclusion: HIAT in an animal model of RD resulted in increased the number of muscle fibers with smaller CSA.
<sec><title>PURPOSE:</title><p>To establish a model of chronic kidney disease in White New Zealand rabbits, using an exclusive unilateral technique of renal ischemia and reperfusion.</p></sec><sec><title>METHODS:</title><p>Twenty males White New Zealand rabbits were used. All animals were subjected to the following: pre-surgical blood collection (1<sup>st</sup> collection) for creatinine and urea serum analysis, left renal ischemia and reperfusion surgery technique, another blood sample was collected after 6 weeks post surgery (2<sup>nd</sup> collection), the last blood sample (3<sup>rd</sup>collection) blood sample was taken 11 weeks post surgery (pre-euthanasia), euthanasia and withdrawal of right and left kidney for histopathological analysis.</p></sec><sec><title>RESULTS:</title><p>The creatinine levels after surgery was statistically significant higher in the 3<sup>rd</sup> collection, regarding the 1<sup>st</sup> and 2<sup>nd</sup>collection (p<0.05). A significant statistic increase for urea was showed only in the 2<sup>nd</sup> collection (p<0.05) when compared to the 1<sup>st</sup>and 3<sup>rd</sup> collections. Histopathological analysis showed bilateral lesions in the renal tissue, consistent to the process of ischemia and reperfusion.</p></sec><sec><title>CONCLUSION:</title><p> This exclusive unilateral technique of renal ischemia and reperfusion without nephrectomy in White New Zealand rabbits, showed effectiveness in getting an animal model of chronic kidney disease</p></sec>