ABSTRACT
Pulmonary arterial hypertension (PAH) is characterized by right ventricular failure and diminished cardiac output, potentially leading to renal and bone impairments. In contrast, resistance exercise training (RT) offers cardiovascular and bone health benefits. This study aimed to assess the impacts of stable PAH induced by monocrotaline (MCT) and RT on renal morphometry, as well as bone morphometry and biomechanical properties in male Wistar rats. Four experimental groups, untrained control (UC, n=7), trained control (TC, n=7), untrained hypertensive (UH, n=7), trained hypertensive (TH, n=7), were defined. After the first MCT or saline injection (20 mg/kg), trained rats were submitted to a RT program (i.e., Ladder climbing), 5 times/week. Seven days later the rats received the second MCT or saline dose. After euthanasia, renal and femoral histomorphometry and femoral biomechanical properties were assessed. PAH reduced renal glomerular area and volume, which was prevented by the RT. While PAH did not harm the femoral morphometry, structural and mechanical properties, RT improved the femoral parameters (e.g., length, percentage of trabeculae and bone marrow, ultimte and yield loads). Experimental stable PAH promotes renal but not bone damages, whereas RT prevents renal deteriorations and improves the femoral morphological and biomechanical properties.
Subject(s)
Disease Models, Animal , Kidney , Monocrotaline , Physical Conditioning, Animal , Rats, Wistar , Resistance Training , Animals , Male , Physical Conditioning, Animal/physiology , Rats , Kidney/physiopathology , Kidney/pathology , Resistance Training/methods , Pulmonary Arterial Hypertension/physiopathology , Femur/pathology , Femur/physiopathology , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/chemically inducedABSTRACT
The aim of this study was to verify the effects of moderate-intensity continuous (MICT) and high-intensity interval (HIIT) aerobic training on cardiac morphology and function and the mechanical properties of single cardiomyocytes in spontaneously hypertensive rats (SHR) in the compensated phase of hypertension. Sixteen-week-old male SHR and normotensive Wistar (WIS) rats were allocated to six groups of six animals each: SHR CONT or WIS CONT (control); SHR MICT or WIS MICT (underwent MICT, 30 min/day, five days per week for eight weeks); and SHR HIIT or WIS HIIT (underwent HIIT, 30 min/day, five days per week for eight weeks). Total exercise time until fatigue and maximum running speed were determined using a maximal running test before and after the experimental period. Systolic (SAP), diastolic (DAP), and mean (MAP) blood pressures were measured using tail plethysmography before and after the experimental period. Echocardiographic evaluations were performed at the end of the experimental period. The rats were euthanized after in vivo assessments, and left ventricular myocytes were isolated to evaluate global intracellular Ca2+ transient ([Ca2+]i) and contractile function. Cellular measurements were performed at basal temperature (~37°C) at 3, 5, and 7 Hz. The results showed that both training programs increased total exercise time until fatigue and, consequently, maximum running speed. In hypertensive rats, MICT decreased SAP, DAP, MAP, interventricular septal thickness during systole and diastole, and the contraction amplitude at 5 Hz. HIIT increased heart weight and left ventricular wall thickness during systole and diastole and reduced SAP, MAP, and the time to peak [Ca2+]i at all pacing frequencies. In conclusion, both aerobic training protocols promoted beneficial adaptations to cardiac morphology, function, and mechanical properties of single cardiomyocytes in SHR.
Subject(s)
Hypertension , Physical Conditioning, Animal , Male , Animals , Rats , Rats, Inbred SHR , Physical Conditioning, Animal/physiology , Rats, Wistar , Hypertension/therapy , Myocytes, Cardiac/physiology , FatigueABSTRACT
Objectives: Verify the validity of electrical bioimpedance (BIA) and the skinfold method in estimating the percentage ofbody fat (% BF) in middle-aged and elderly women, using dual emission X-ray absorptiometry (DXA) as a reference method.Material and methods: The sample consisted of 106 volunteers (middle age, n = 58 [51.3 ± 4.9 years] and elderly, n = 48[67.2 ± 5.8 years]). The volunteers were submitted to anthropometric assessments and the % BF was subsequently calculatedusing the Jackson and Pollock 7 skinfold protocol (7SF). The % BF was also measured using BIA and DXA. Pearsons correlation,Bland and Altman method, effect size and repeated-measure t-test were used to test the hypotheses.Results: Although there is a moderate positive relationship between the methods evaluated for middle-aged women (DXAvs 7SF, r = 0.67; DXA vs BIA, r = 0.62) and moderate to strong for the elderly (DXA vs 7SF, r = 0.57; DXA vs BIA, r = 0.75) (p ≤ 0.05in all analyzes), the agreement between the methods was weak (limits of agreement > ± 3.5%). Additionally, when assessingthe % BF mean using each method within the groups, it was observed that there was no significant difference between theestimates only between DXA and Pollock 7SF in the elderly group.Conclusion: Therefore, both the 7SF method and the BIA are not valid for estimating body fat in the sample evaluated. It isnecessary to develop equations for specific skinfolds to estimate the % BF of middle-aged and elderly women and reviewthe equations used by the BIA.(AU)
Objetivo: Verificar la validez de la bioimpedancia eléctrica (BIA) y el método del pliegue cutáneo en la estimación delporcentaje de grasa corporal (% GC) en mujeres de mediana edad y ancianas, mediante la doble emisión de rayos X (DXA )como método de referencia.Material y método: La muestra estuvo formada por 106 voluntarias (mediana edad, n = 58 [51,3 ± 4,9 años] y ancianas, n= 48 [67,2 ± 5,8 años]). Las voluntarias fueron sometidas a evaluaciones antropométricas y, posteriormente, se calculó el %GC utilizando el protocolo de pliegues cutáneos Jackson y Pollock 7 (7PC). El% de GC también se midió usando BIA y DXA.La correlación de Pearson, el método de Bland y Altman, el tamaño del efecto y la prueba t de medida repetida se utilizaronpara probar las hipótesis.Resultados: Aunque existe una relación positiva moderada entre los métodos evaluados para mujeres de mediana edad (DXAvs 7PC, r = 0,67; DXA vs BIA, r = 0,62) y moderada a fuerte para las ancianas (DXA vs 7PC, r = 0,57 ; DXA vs BIA, r = 0,75) (p ≤ 0,05en todos los análisis), la concordancia entre los métodos fue débil (límites de acuerdo > ± 3,5%). Además, al evaluar la mediade % GC usando cada método dentro de los grupos, se observó que no hubo diferencia significativa entre las estimacionessolo entre DXA y Pollock 7PC en el grupo de ancianas.Conclusiones: Por tanto, tanto el método 7PC como el BIA no son válidos para estimar la grasa corporal en la muestra eva-luada. Es necesario desarrollar ecuaciones para pliegues cutáneos específicos para estimar el % GC de mujeres de medianaedad y ancianas y revisar las ecuaciones utilizadas por el BIA.(AU)
