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  • Author: Chi-Yao Chang x
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Abstract

Background: Advanced glycation end-products (AGEs) due to hyperglycemia have been reported with diabetic complications. The effect of angiotensin converting enzyme (ACE) inhibition on the formation of AGEs and oxidative stress in the myocardium was explored.

Methods: Streptozocin-induced diabetic rats were randomized to three groups including untreated, treated with ACE inhibitor captopril, and treated with aminoguanidine for 24 weeks with non-diabetic rats as control.

Results: At study end, elevations of blood pressure, heart to body weight ratio, and brain natriuretic peptide levels were found in diabetic rats, indicating cardiac hypertrophy and dysfunction. Accumulation of myocardial AGEs/ receptor of AGEs (RAGEs), as determined by immunohistochemistry and Western blots were increased in diabetic animals, which were attenuated by both captopril and aminoguanidine. Staining of nitrotyrosine and 8-hydroxydeaminoguanosine, markers of oxidative stress, also increased in diabetic rats and was attenuated by both captopril and aminoguanidine treatment. The myocardial pentosidine, a marker of AGEs, increased in diabetic rats but was not significantly affected by either treatment.

Conclusion: This study has identified a relationship between the renin-angiotensin system and the accumulation of AGEs in experimental diabetic hearts that may be linked through oxidative stress.

Abstract

Previous research in badminton has associated unilateral landings following overhead strokes with the occurrence of knee injuries. Smashing involves tensing the abdomen muscles while swinging the racket rapidly and maintaining one’s balance while performing coordinated movements and steps; this process puts stress on the player’s lower limbs. However, few studies have compared the effects of different stroke training while performing various types of badminton strokes. This study investigated the influence of different stroke training on the smash action of badminton players. Three stroke training conditions were considered: shadow, target striking, and smashing. Sixteen male experienced badminton players were recruited for this study. One-way repeated-measures ANOVA with Bonferroni correction was used to identify the differences. At the initial contact with the ground, the knee flexion and knee valgus angles under the smash condition were significantly higher than target and shadow conditions. Under the smash condition, hip abduction was significantly higher than under the target and shadow conditions. Moreover, the hip abduction under the target condition was significantly higher than under the shadow condition. At the maximum knee flexion, the hip abduction under the smash and target conditions was significantly higher than under the shadow condition. Regarding the time from the moment of initial contact to the peak of vertical ground reaction force it was shorter under the smash condition than the target and shadow conditions. The vertical ground reaction force was higher under the smash condition than under the target and shadow conditions. The 50 ms impulse was higher under the smash condition than under the target and shadow conditions. The main findings of this study are that under the smash condition, the motion in the frontal plane increased, which produced higher loads on the joints in the lower limbs. Player performed the same footwork under the three conditions, but the landing strategies differed because of unique swing motions and techniques. The condition under which a player hits a shot to a target area can affect the landing. The results of this study suggest that target practice is more effective for improving the landing technique employed during actual shots than shadow practice.