Adult rats were given a single retrobulbar injection of 50 microliters of 2.0% mepivacaine and the lateral rectus muscles were examined ultrastructurally at intervals from 15 min to 30 days post-injection. There were three purposes of the study: (1) to determine the extent of muscle fiber damage caused by the anesthetic; (2) to document the subsequent course of muscle fiber regeneration; and (3...

BACKGROUND Duchenne Muscular Dystrophy (DMD) is characterized by increased muscle damage and an abnormal blood flow after muscle contraction: the state of functional ischemia. Until now, however, the cause-effect relationship between the pathogenesis of DMD and functional ischemia was unclear. We examined (i) whether functional ischemia is necessary to cause contraction-induced myofiber damage ...

AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HI...

BACKGROUND Eccentric exercise-induced damage leads to reductions in muscle force, increased soreness, and impaired muscle function. Creatine monohydrate's (Cr) ergogenic potential is well established; however few studies have directly examined the effects of Cr supplementation on recovery after damage. We examined the effects of Cr supplementation on muscle proteins and force recovery after ecc...

Central core disease (CCD) is a congenital myopathy linked to mutations in the ryanodine receptor type 1 (RYR1), the sarcoplasmic reticulum Ca2+ release channel of skeletal muscle. CCD is characterized by formation of amorphous cores within muscle fibers, lacking mitochondrial activity. In skeletal muscle of RYR1Y522S/WT knock-in mice, carrying a human mutation in RYR1 linked to malignant hyper...

In laboratory rodents, caloric restriction (CR) retards several age-dependent physiological and biochemical changes in skeletal muscle, including increased steady-state levels of oxidative damage to lipids, DNA, and proteins. We used immunogold electron microscopic (EM) techniques with antibodies raised against 4-hydroxy-2-nonenal (HNE) -modified proteins, dinitrophenol, and nitrotyrosine to qu...

Hill races usually include large downhill running sections, which can induce significant degrees of muscle damage in a field setting. This study examined the link between muscle damage, oxidative stress, and immune perturbations following a 7-km mountainous hill race with 457 m of ascent and 457 m of descent. Venous blood samples were taken from 7 club level runners before, immediately after, a...