Muscle denervation is one of the most critical pathological factors involved in muscle atrophy as a result of ageing. This study aims to investigate the chronic effect of high-intensity interval training (HIIT) on cross-sectional areas and muscle denervation genes, interpreted in the plantaris muscle atrophy of aged rats. Twenty-eight aged and young rats were divided into four different groups, including exercise and control. The training protocol included six weeks of HIIT. Animals were sacrificed 48 hours after the last training session, and the plantaris muscle was removed. To measure Gadd45a mRNA and NCAM1mRNA, we used a real-time PCR technique. The cross-sectional area was measured with photomyography using an H&E technique. The results showed that ageing significantly decreased NCAM1 mRNA in the aged control group (p=0.0001) and exercise leads to a significant increase (interaction effect) of it (p=0.003). Gadd45a mRNA was significantly increased due to ageing (p=0.009), and exercise resulted in a significant decrease in that in the aged exercise group (p=0.04). The cross-sectional area in the aged control group was significantly smaller than in the young control group (p=0.046). In contrast to young groups, exercise could increase the cross-sectional area in the aged exercise group compared with the aged control group, but it was not significant (p=0.069). It seems that HIIT could improve ageing-induced muscular atrophy, although denervation-involved gene modification leads to an increase in the muscular cross-sectional area; therefore, it improves muscular atrophy due to ageing. KEY WORDS high-intensity interval training, muscular atrophy, muscle denervation, ageing, gadd45a protein, ncam1 protein ORIGINAL SCIENTIFIC PAPER
Objective To determine the association between having simultaneously high body mass index (BMI) and high relative lean body mass (LBM) and cardio‐metabolic risk factors, metabolic syndrome (MetS), and diabetes in adults. Materials and Methods A cross‐sectional analysis was performed on 4982 adults aged 19‐85 years that participated in the National Health and Nutrition Examination Survey (cycles 1999‐2000‐2005‐2006). The primary exposure variable was categorization into four groups: (a) Low‐BMI/Low‐LBM, (b) Low‐BMI/High‐LBM, (c) High‐BMI/Low‐LBM, and (d) High‐BMI/High‐LBM. LBM was assessed using dual‐energy X‐ray absorptiometry. The primary outcome measures were cardio‐metabolic risk factors, MetS based on the ATP III definition; participants were required to have at least three of the following five criteria: high waist circumference, low HDL cholesterol, elevated triglyceride levels, high resting blood pressure, and self‐reported diabetes. Results Compared to the High‐BMI/High‐LBM, most cardio‐metabolic risk factors were significantly different among groups (P < .05) while no such differences were observed for the High‐BMI/Low‐LBM (P > .05). Exception of waist circumference (OR [95%]: 21.8 [8.84‐53.82]), there was no increased odds of having cardio‐metabolic risk factors in the High‐BMI/Low‐LBM compared with the High‐BMI/High‐LBM (P > .05). The odds of having MetS and diabetes for the High‐BMI/Low‐LBM compared with the High‐BMI/High‐LBM were OR (95% CI): 1.68 (0.84‐3.36) and 0.59 (0.26‐1.34), respectively. Conclusions Our results suggest that having a high‐BMI as well as high relative LBM levels is not associated with cardio‐metabolic risk factors, MetS, and diabetes. Therefore, maintaining a BMI below 30 kg/m2 appears to be clinically relevant, regardless of LBM levels.
Aims: To investigate the correlations between meeting the muscle-strengthening activities guideline, body fat %, and mortality for individuals living with obesity and to explore if these correlations are moderated by sex.Methods: Data from 3915 adults (51.9% women; 48.1% men) living with obesity (body fat % ≥25 for men and ≥35 for women) from two cycles of the National Health and Nutrition Examination Survey (NHANES 2003(NHANES -04/2005 were analyzed.Muscle-strengthening activities were self-reported via a questionnaire, body fat % was measured via Dual Energy X-ray, and mortality was obtained via administrative data for an average of 10 years.Results: 18.7% of men and 15.2% of women living with obesity met the musclestrengthening activities guideline (p = 0.021). Sex was correlated with body fat %;(β (SE)= 11.34 (0.18); p ≤ 0.001) and risk of mortality (hazard ratio (95% confidence interval) = 0.36 (0.24-0.54); p ≤ 0.001), once adjusted for confounders (weekly aerobic activities, ethnicity, education, household income, smoking, and the sum of chronic conditions). The interaction between sex and meeting the muscle-strengthening activities guideline was not significantly correlated with the studied outcomes. Conclusion:Performing muscle-strengthening activities a minimum of two times per week does not impact body fat % or risk of mortality (over 10 years) differently in men or women living with obesity.
Background Hamster is widely used as an experimental model in the study of reproductive system. However, pregnancy diagnosis and aging always have been a challenge. ultrasonography have been used in diagnosis of pregnancy in some small laboratory animals, such as rabbits, rats, and mice. Current study describes use of trans-abdominal ultrasonography for pregnancy diagnosis and fetal age estimation in golden hamster. Furthermore, a macroscopic examination was performed to evaluate the embryonic vesicle diameter, crown-rump length, and fetal head diameter. Ten adult female golden hamsters were selected and maintained under controlled light conditions (14 h light/10 h darkness). The estrous cycle was synchronized using eCG and hCG. During estrous (18 h after hCG injection), the hamsters were naturally mated. After seven days of mating, the hamsters were examined daily for pregnancy diagnosis and aging with an ultrasound scanner equipped with an 8.5-MHZ linear probe. On each day of the experiment, at least one of the pregnant hamsters was euthanized and dissected for macroscopic fetal measurements using a digital caliper. Results The gestational sac and crown-rump length were identified and measured by ultrasonographicly on day 7 of pregnancy and head could be visible after day 10 of gestation. Statistical analysis revealed that the ultrasound estimation of gestational age was significantly correlated with the actual age of the fetus (r = 0.98; p < 0.05). Conclusions Real-time ultrasound can be used for the diagnosis of pregnancy and estimation of fetal age in golden hamster from day 7 of gestation.
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