Plasma Activity of Muscle Enzymes: Quantification of Skeletal Muscle Damage and Relationship with Metabolic Variables

Abstract

One hundred fourteen sedentary volunteers (34 +/- 8 years) took part in an endurance training study to be completed after 18-20 months with a marathon. Ultimately, 60 males and 18 females achieved that goal. The training program, carefully supervised, was divided into three periods with a maximum of 45-, 70-, and 110-km week training volume and concluded with a performance race of 15, 25, and 42.2 km, respectively. Three days before and 3 and 5 days after each race, 35 subjects were selected to perform a progressive treadmill test and the remaining subjects participated in field tests of 400 and 1000 m. A significant decrease in half-life time of CK enzyme plasma activity after running long distances in the course of the study from 20 h to 13 h was observed. Based on plasma enzyme activity and supposing that the total enzyme content left the muscle fiber, the estimated amount of muscle damage was found to be small. A gender difference in plasma enzyme activity increase (females demonstrated a lower increase) occurred only after the marathon.

Lactacidemia e concentrações séricas de aspartato aminotransferase e creatinoquinase em equinos da raça Quarto de Milha usados em provas de laço em dupla

“…Porém, em todos os momentos de avaliação, os valores foram bem inferiores aos descritos por Janssen et al (1989), Harris et al (1998) e Aleman (2008), além do fato que clinicamente os equinos não demonstraram quaisquer alterações e seguiram bem para as fases seguintes das provas.…”

Serum alanine aminotransferase in skeletal muscle diseases†

“…However, skeletal muscle is known to contain isozymes of creatine kinase, lactate dehydrogenase (LDH), AST, and ALT, which may be released into the blood stream following muscle necrosis. 1 Although reports of elevations in AST and ALT levels in patients with isolated skeletal muscle injury exist in the literature, there is still a pervasive lack of recognition of the correlation between skeletal muscle injury and ALT elevation, which has led to the unsubstantiated conclusion that serum aminotransferase elevations are due to liver injury or that liver injury is a secondary consequence of rhabdomyolysis. 2 Therefore, we evaluated the pattern of serum aminotransferase elevation in patients with skeletal muscle injury due to various etiologies in the documented absence of liver disease.…”

Nutritional Interventions as Potential Strategy to Minimize Exercise-Induced Muscle Injuries in Sports

“…Creatine supplementation was effective in significantly attenuate the observed increase in all muscle soreness markers analyzed, unlike CK, thus pointing this nutritional intervention as an effective strategy in maintaining muscle integrity during and after intense and prolonged endurance exercise. In fact the lack of effect upon plasma CK concentration might not reflect the overall positive effect of creatine on muscle damage as a strong variability of this parameter among athletes, its dependence from the training status and the weak correlation with changes in other markers of muscle damage [151][152][153] lessen its significance in comparison with other markers of cellular death and lysis as LDH [154]. Similar effects on plasma pro inflammatory markers (Interleukin (IL) 1 beta and IL-6, TNF-α, and Interferon alpha (INF alpha) and PGE2) [155] and on plasma markers of cellular integrity (CK, LDH aldolase (ALD), glutamic oxaloacetic, acid transaminase (GOT), glutamic pyruvic acid transaminase (GPT), and C-reactive protein (CRP) [156] have been obtained in double blind trials following creatine supplementation (20gr day-1) 5 days before a half-ironman and after ironman triathlon competition respectively.…”