Rhabdomyolysis and myohemoglobinuric acute renal failure.

Increased serum enzyme activity after exercise was first reported in 1958; subsequent studies have established that many factors determine the degree to which the serum activities of a variety of enzymes increase during and after exercise. The serum activities of those enzymes found especially in muscle, particularly creatine kinase, increase in proportion to the intensity and duration of the preceding exercise, peaking 24 hours after exercise; the effect of duration is dominant, so that the highest postexercise serum enzyme activities are found after very prolonged competitive exercise such as ultradistance marathon running or triathlon events. Weight-bearing exercises which include eccentric muscular contractions such as bench stepping and downhill running induce the greatest increases in serum enzyme activities; serum enzyme activities increase very little even after prolonged participation in those non-weight-bearing activities such as swimming and cycling which do not include eccentric muscular contractions. Prolonged (greater than 2 hours) daily training or competition in weight-bearing activities produces chronically elevated serum enzyme activities. Serum enzyme activities increase more with exercise in males, Blacks and the untrained than they do in females, Whites and the trained, respectively; age does not appear to influence the degree to which serum enzyme activities increase with exercise. There is a remarkable individual variability in the degree to which serum enzyme activities increase with exercise; a 50-fold difference in post-race serum creatine kinase activities has been found in healthy and equally trained athletes completing the same 90km ultramarathon footrace. The biochemical explanation for this degree of individual variability is not currently understood; possibly persons who show abnormally large increases in serum enzyme activities with exercise may have as yet unrecognised subclinical myopathies. No circadian rhythms have been identified for serum enzyme activities; activities rise during the day because of increased physical activity. The rise in serum enzyme activities is greater after exercise at altitude or in the heat than after equivalent exercise at sea level or in the cold. The most likely explanation for the increased serum enzyme activities that follow prolonged weight-bearing activities that also cause marked muscle soreness, is myofibrillar damage in particular sarcomeric Z-disk disruption.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of exercise on serum enzyme activities in humans.

Reactive oxygen metabolites, in particular hydroxyl radical, have been shown to be important mediators of tissue injury in several models of acute renal failure. The aim of the present study was to examine the role of hydroxyl radical in glycerol-induced acute renal failure, a model for myoglobinuric renal injury. Rats injected with glycerol alone (8 mg/kg im following dehydration for 24 h) developed significant renal failure compared with dehydrated controls. Rats treated with glycerol and a hydroxyl radical scavenger, dimethylthiourea (DMTU), had significantly lower blood urea nitrogen (BUN) and creatinine. In contrast, urea, which is chemically similar to DMTU but is not a hydroxyl radical scavenger, provided no protection. In addition, DMTU prevented the glycerol-induced rise in renal cortical malondialdehyde content (a measure of lipid peroxidation that serves as a marker of free radical-mediated tissue injury). A second hydroxyl radical scavenger, sodium benzoate, had a similar protective effect on renal function (as measured by both BUN and creatinine). Because the generation of hydroxyl radical in biological systems requires the presence of a trace metal such as iron, we also examined the effect of the iron chelator, deferoxamine on glycerol-induced renal failure. Deferoxamine was also protective. The interventional agents were also associated with a marked reduction in histological evidence of renal damage. The protective effects of two hydroxyl radical scavengers as well as an iron chelator implicate a role for hydroxyl radical in glycerol-induced acute renal failure.

Evidence suggesting a role for hydroxyl radical in glycerol-induced acute renal failure

https://www.annemergmed.com/article/S0196-0644(94)70356-6/pdf

Exercise-Induced Rhabdomyolysis

We investigated whether there is a break point of creatine kinase (CK) release after daily endurance exercise and whether CK response depends on individual physical characteristics. Fifteen healthy young men performed 90 min of bicycle exercise for 3 consecutive days. Body composition, properties of the quadriceps femoris muscle (QFM), and aerobic and anaerobic capacities were estimated before the test. Blood samples were obtained 22 times during the experimental period. Endurance exercise significantly elevated serum CK from 3 h after the first exercise session (P 500 IU/l of CK) and low responders (LR; <300 IU/l of CK). Peak CK values during the experimental period correlated (P < 0.01) with workload/cross-sectional area of the QFM (r = 0.658), workload/volume of the QFM (r = 0.648), and knee extensor strength/body mass (r = -0.634); however, the HR and LR groups were separated in each variable. Thus the break point of CK release after endurance exercise under these conditions is 300-500 IU/l, two or three times higher than in the resting condition, and is associated with properties of the QFM.

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.01270.2001

Break point of serum creatine kinase release after endurance exercise

This study was conducted to determine, on a prospective basis, the incidence of acute exertional rhabdomyolysis (AER) among recruits at the Marine Corps Recruit Depot, San Diego, Calif. Blood samples were taken from each of 337 volunteer recruits on each of their first six days of regularly scheduled training. Serum myoglobin, serum creatine phosphokinase, lactic dehydrogenase, and serum glutamic oxaloacetic transaminase values were used as indicators of muscle injury. Substantial elevations of serum enzyme activity were observed throughout the study population. Of the study population, 39.2% had serum myoglobin levels that ranged from 0.37 mug/ml to 21.9 mug/ml during the study interval. Six subjects had serum myoglobin levels consistent with those reported in clinical cases of AER. It is concluded that, in a recruit population, large numbers of men may have myoglobinemia but not be seen initially as clinical cases.

Incidence of acute exertional rhabdomyolysis. Serum myoglobin and enzyme levels as indicators of muscle injury.

MYOGLOBINURIA is generally considered uncommon, although it has been reported in a wide variety of clinical conditions.1 The potential for acute tubular necrosis and renal failure associated with m...

John E. Olerud

Papers

Incidence of acute exertional rhabdomyolysis. Serum myoglobin and enzyme levels as indicators of muscle injury.

Serum myoglobin levels predicted from serum enzyme values.

Serum myoglobin levels associated with severe exercise.