Physical activity and hypophysectomy on the aerobic capacity of ligaments and tendons

Abstract

Traditionally, ligaments and tendons (L and T) have been regarded as metabolically inert structures. However, sufficient biochemical evidence on the metabolism of collagen has indicated that such a concept is no longer tenable. To determine whether L and T respond to increased or decreased levels of chronic exercise, studies were undertaken to measure their aerobic capacities. For comparative purposes, similar measurements were obtained from liver and skeletal muscles secured from normal and hypophysectomized male rats. Oxygen consumption and cytochrome oxidase (CO) activity was recorded from cell suspensions that had been prepared with the inclusion of collagenase and with elastase added to the medium. The O2 results showed that L and T had values that were approximately 10 times lower than liver tissue and 7.5 times less than the means from skeletal muscles. Hypophysectomy caused marked reductions in O2 uptake of liver and muscle tissues; but had no impact on L and T. When CO activity of these connective tissues were evaluated, immobilization and hypophysectomy caused significant reductions that ranged from -36% to -59% respectively. Training, on the other hand, resulted in increases of less than 10% in the activity of this enzyme within L and T while being elevated in muscle tissue by 58%. It was concluded that the metabolic activity of L and T was lowered with decreased levels of physical activity but it was unclear why chronic exercise did not produce the opposite effect.

The Achilles Tendinopathy: Pathogenesis Review

“…Athletes performing sport activities that include running or jumping are those foot inversion and impingement; all these factors and others such as muscle weakness, decreased flexibility, joint laxity or stiffness, independently or together, may affect the way the Achilles tendon is loaded [28,61] . Blood Supply: Tendons and ligaments have 7.5 times lower oxygen consumption compared with skeletal muscle [62] . The low metabolic rate and well developed anaerobic energy generation capacity are essential to carry loads and maintain tension for long periods, reducing the risk of ischemia and subsequent necrosis [29] .…”

Chronic tendon pathology: molecular basis and therapeutic implications

“…They all possess a small protein core (36)(37)(38)(39)(40)(41)(42) The most abundant proteoglycan in tendon is decorin, although biglycan is also present in small amounts (Ref. 57).…”

Iontophoresis with or without dexamethazone in the treatment of acute Achilles tendon pain

“…Historically, it was thought that tendon tissue was metabolically inert but today it is well known that tendon cells have an active metabolism (Vailas et al, 1978). The oxygen consumption of the Achilles tendon has, however, been shown to be 7.5 times lower than that in skeletal muscle as measured in the rat (Vailas et al, 1978).…”

“…The oxygen consumption of the Achilles tendon has, however, been shown to be 7.5 times lower than that in skeletal muscle as measured in the rat (Vailas et al, 1978). Even though tendon has a lower metabolic rate when compared with muscle tissue, it is apparently adequate for the needs of the tendon tissue (Józsa and Kannus, 1997).…”