Effect of long-term caloric restriction and exercise on muscle bioenergetics and force development in rats

Alena Horská, Larry J. Brant, Donald K. Ingram, Richard G. Hansford, George S. Roth, Richard G.S. Spencer

Research output: Contribution to journalArticle

Abstract

We evaluated the hypothesis that long-term caloric restriction and exercise would have beneficial effects on muscle bioenergetics and performance in the rat. By themselves, each of these interventions is known to increase longevity, and bioenergetic improvements are thought to be important in this phenomenon. Accordingly, we investigated rats that underwent long-term caloric restriction and were sedentary, ad libitum-fed rats permitted to exercise by daily spontaneous wheel running (AE), and the combination of the dietary and exercise interventions (RE). Ad libitum-fed, sedentary rats comprised the control group, 31P NMR spectra of the gastrocnemius muscle (GM) were collected in vivo at rest and during two periods of electrical stimulation. Neither caloric restriction nor exercise affected the ratio of phosphocreatine to ATP or pH at rest. During the first stimulation and after recovery, the RE group had a significantly smaller decline in pH than did the other groups (P < 0.05). During the second period of stimulation, the decrease in pH was much smaller in all groups than during the first stimulation, with no differences observed among the groups. The combination of caloric restriction and exercise resulted in a significant attenuation in the decline in developed force during the second period of stimulation (P < 0.05). A biochemical correlate of this was a significantly higher concentration of citrate synthase in the GM samples from the RE rats (32.7 ± 5.4 μmol · min-1 · g-1) compared with the AE rats (17.6 ± 5.7 μmol · min-1 · g-1; P < 0.05). Our experiments thus demonstrated a synergistic effect of long-term caloric restriction and free exercise on muscle bioenergetics during electrical stimulation.

Original languageEnglish (US)
Pages (from-to)E766-E773
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume276
Issue number4 39-4
DOIs
StatePublished - Apr 1999

Keywords

  • Energy metabolism
  • Nuclear magnetic resonance spectroscopy
  • Skeletal muscle

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Physiology (medical)

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