Metabolic Adaptations of Skeletal Muscle to Voluntary Wheel Running Exercise in Hypertensive Heart Failure Rats

Abstract

The Spontaneously Hypertensive Heart Failure (SHHF) rat mimics the human progression of hypertension from hypertrophy to heart failure. However, it is unknown whether SHHF animals can exercise at sufficient levels to observe beneficial biochemical adaptations in skeletal muscle. Thirty-seven female SHHF and Wistar-Furth (WF) rats were randomized to sedentary (SHHFsed and WFsed) and exercise groups (SHHFex and WFex). The exercise groups had access to running wheels from 6-22 months of age. Hindlimb muscles were obtained for metabolic measures that included mitochondrial enzyme function and expression, and glycogen utilization. The SHHFex rats ran a greater distance and duration as compared to the WFex rats (P<0.05), but the WFex rats ran at a faster speed (P<0.05). Skeletal muscle citrate synthase and β-hydroxyacyl-CoA dehydrogenase enzyme activity was not altered in the SHHFex group, but was increased (P<0.05) in the WFex animals. Citrate synthase protein and gene expression were unchanged in SHHFex animals, but were increased in WFex rats (P<0.05). In the WFex animals muscle glycogen was significantly depleted after exercise (P<0.05), but not in the SHHFex group. We conclude that despite robust amounts of aerobic activity, voluntary wheel running exercise was not sufficiently intense to improve the oxidative capacity of skeletal muscle in adult SHHF animals, indicating an inability to compensate for declining heart function by improving peripheral oxidative adaptations in the skeletal muscle.

Voluntary wheel exercise training affects locomotor muscle, but not the diaphragm in the rat

“…Probably, the speed of voluntary wheel running may be an indicator of the functional state of the organism. For example, wheel running speed in heart failure rats is one and a half times lower than in healthy rats ( Schultz et al, 2013 ).…”

Low‐intensity aerobic exercise improves cardiac remodelling of adult spontaneously hypertensive rats

“…Spontaneously, hypertensive rats (SHR) subjected to long‐term voluntary wheel running have presented worse cardiac remodelling than sedentary SHR. In voluntary, wheel running SHR usually perform short series of relatively high‐intensity stints reaching many kilometres a day . It is therefore possible that a high‐intensity exercise programme produces deleterious cardiac effects when performed under increased afterload.…”

İstemli Egzersizin Sıçanlarda Fruktozdan Zengin Beslenmeyle Uyarılan Böbrek Fonksiyon Bozukluğu ve Oksidan Durumu Düzeltici Etkisi

“…Günlük tekerlek devirleri saat yönü, saat yönünün tersi ve toplam tur sayısı olarak kayıt edilerek kat edilen mesafe km/gün olarak belirlendi. Uygulamaya başlamadan önce aktivite gruplarındaki tüm sıçanlara bir hafta boyunca dönen tekerlekli kafeslerde tekerleği tanımaları ve kullanabilmeleri için alıştırma yaptırıldı 12 . Doku-kan örneklerinin alınması ve analizler: Çalışmanın sonunda sıçanlara anestezi için ketamin (60 mg/kg) ve ksilazin (5 mg/kg) intraperitoneal uygulandı.…”