Muscle changes with high-intensity aerobic training in an animal model of renal disease

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.

Animal model of chronic kidney disease using a unilateral technique of renal ischemia and reperfusion in White New Zealand rabbits

PURPOSE: To establish a model of chronic kidney disease in White New Zealand rabbits, using an exclusive unilateral technique of renal ischemia and reperfusion. METHODS: Twenty males White New Zealand rabbits were used. All animals were subjected to the following: pre-surgical blood collection (1st collection) for creatinine and urea serum analysis, left renal ischemia and reperfusion surgery technique, another blood sample was collected after 6 weeks post surgery (2nd collection), the last blood sample (3rd collection) blood sample was taken 11 weeks post surgery (pre-euthanasia), euthanasia and withdrawal of right and left kidney for histopathological analysis. RESULTS: The creatinine levels after surgery was statistically significant higher in the 3rd collection, regarding the 1st and 2nd collection (p<0.05). A significant statistic increase for urea was showed only in the 2nd collection (p<0.05) when compared to the 1st and 3rd collections. Histopathological analysis showed bilateral lesions in the renal tissue, consistent to the process of ischemia and reperfusion. CONCLUSION: 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 .

Variação diurna de parâmetros de função pulmonar e de força muscular respiratória em pacientes com DPOC / Diurnal variations in the parameters of pulmonary function and respiratory muscle strength in patients with COPD

OBJETIVO: Avaliar a magnitude de mudanças diurnas em parâmetros de função pulmonar e de força e resistência dos músculos respiratórios em uma amostra de pacientes com DPOC. MÉTODOS: Um grupo com 7 pacientes foi submetido a espirometria e a determinação de PImáx e PEmáx em dois momentos (entre 8h00 e 8h30 e entre 16h30 e 17h00) em um único dia. Os pacientes permaneceram em repouso na área do laboratório entre as avaliações. RESULTADOS: De acordo com o sistema de estadiamento da Global Initiative for Chronic Obstructive Pulmonary Disease, a doença foi classificada em moderada, grave e muito grave em 1, 3 e 3 pacientes, respectivamente. Da primeira para a segunda avaliação, houve uma queda significativa em CVF, VEF1 e PEmáx (de 13%, 15% e 10%, respectivamente), bem como uma queda não significativa em PFE, PImáx e ventilação voluntária máxima (de 9%, 3% e 11%, respectivamente). CONCLUSÕES: Nesta amostra de pacientes com DPOC, houve variações diurnas nos parâmetros de função pulmonar e de força de músculos respiratórios. Os valores de VEF1, CVF e PEmáx foram significativamente menores à tarde do que de manhã.

OBJECTIVE: To evaluate the magnitude of diurnal changes in the parameters of pulmonary function and respiratory muscle strength/endurance in a sample of patients with COPD. METHODS: A group of 7 patients underwent spirometry, together with determination of MIP and MEP, at two distinct times (between 8:00 and 8:30 a.m. and between 4:30 and 5:00 p.m.) on a single day. Between assessments, the patients remained at rest in the laboratory. RESULTS: In accordance with the Global Initiative for Chronic Obstructive Pulmonary Disease staging system, COPD was classified as moderate, severe, and very severe in 1, 3, and 3 of the patients, respectively. From the first to the second assessment, there were significant decreases in FVC, FEV1, and MEP (of 13%, 15%, and 10%, respectively), as well as (less than significant) decreases in PEF, MIP, and maximal voluntary ventilation (of 9%, 3%, and 11%, respectively). CONCLUSIONS: In this sample of COPD patients, there were diurnal variations in the parameters of pulmonary function and respiratory muscle strength. The values of FEV1, FVC, and MEP were significantly lower in the afternoon than in the morning.