Increased Serum Creatine Kinase Activity Research Articles

Hexavalent chromium inhibits myogenic differentiation and induces myotube atrophy

Hexavalent chromium [Cr(VI)] is extensively used in many industrial processes. Previous studies reported that Cr(VI) exposures during early embryonic development reduced body weight with musculoskeletal malformations in rodents while exposures in adult mice increased serum creatine kinase activity, a marker of muscle damage. However, the impacts of Cr(VI) on muscle differentiation remain largely unknown. Here, we report that acute exposures to Cr(VI) in mouse C2C12 myoblasts inhibit myogenic differentiation in a dose-dependent manner. Exposure to 2 μM of Cr(VI) resulted in delayed myotube formation, as evidenced by a significant decrease in myotube formation and expression of muscle-specific markers, such as muscle creatine kinase (Mck), Myocyte enhancer factor 2 (Mef2), Myomaker (Mymk) and Myomixer (Mymx). Interestingly, exposure to 5 μM of Cr(VI) completely abolished myotube formation in differentiating C2C12 cells. Moreover, the expression of key myogenic regulatory factors (MRFs) including myoblast determination protein 1 (MyoD), myogenin (MyoG), myogenic factor 5 (Myf5), and myogenic factor 6 (Myf6) were significantly altered in Cr(VI)-treated cells. The inhibitory effect of Cr(VI) on myogenic differentiation was further confirmed in freshly isolated mouse satellite cells, a stem cell population essential for adult skeletal muscle regeneration. Furthermore, Cr(VI) exposure to fully differentiated C2C12 myotubes resulted in a decrease in myotube diameter, which was exacerbated upon co-treatment with dexamethasone. Together, our results demonstrate that Cr(VI) inhibits myogenic differentiation and induces myotube atrophy in vitro.

Atypical myopathy in 2 Bactrian camels.

Atypical myopathy (AM) is an acute seasonal rhabdomyolysis seen primarily in equids, caused by the ingestion of sycamore maple samaras containing hypoglycin A (HGA) and methylenecyclopropyl-glycine (MCPG). Toxic metabolites inhibit acyl-CoA dehydrogenases and enoyl-CoA hydratases, causing selective hyaline degeneration of type I muscle fibers. Two zoo-kept Bactrian camels (Camelus bactrianus) with a fatal course of AM had sudden onset of muscle pain and weakness, recumbency, and dysphagia, accompanied by increased serum creatine kinase activity and detection in serum of HGA, MCPG, and metabolites. Medical treatment was ineffective. At postmortem examination, sycamore maple tree material was found within the first gastric compartment of the 2-y-old gelding. Although musculature was macroscopically normal, histologically, monophasic hyaline degeneration was marked within type I fibers of intercostal and hypoglossal muscles of the gelding, and in neck, tongue, and masticatory muscles of the cow. The ingestion of sycamore maple material can cause AM in Bactrian camels, and trees of the Sapindaceae family should be avoided in enclosures.

Loss of membrane integrity drives myofiber death in lipin1-deficient skeletal muscle.

Mutations in lipin1 are suggested to be a common cause of massive rhabdomyolysis episodes in children; however, the molecular mechanisms involved in the regulation of myofiber death caused by the absence of lipin1 are not fully understood. Loss of membrane integrity is considered as an effective inducer of cell death in muscular dystrophy. In this study, we utilized a mouse line with selective homozygous lipin1 deficiency in the skeletal muscle (Lipin1Myf5cKO) to determine the role of compromised membrane integrity in the myofiber death in lipin1‐deficient muscles. We found that Lipin1Myf5cKO muscles had significantly elevated proapoptotic factors (Bax, Bak, and cleaved caspase‐9) and necroptotic proteins such as RIPK1, RIPK3, and MLKL compared with WT mice. Moreover, Lipin1Myf5cKO muscle had significantly higher membrane disruptions, as evidenced by increased IgG staining and elevated uptake of Evans Blue Dye (EBD) and increased serum creatine kinase activity in Lipin1Myf5cKO muscle fibers. EBD‐positive fibers were strongly colocalized with apoptotic or necroptotic myofibers, suggesting an association between compromised plasma membrane integrity and cell death pathways. We further show that the absence of lipin1 leads to a significant decrease in the absolute and specific muscle force (normalized to muscle mass). Our work indicates that apoptosis and necroptosis are associated with a loss of membrane integrity in Lipin1Myf5cKO muscle and that myofiber death and dysfunction may cause a decrease in contractile force.

Synergistic effects of Ficus Carica extract and extra virgin olive oil against oxidative injury, cytokine liberation, and inflammation mediated by 5-Fluorouracil in cardiac and renal tissues of male albino rats

5-Fluorouracil (5-FU), a chemotherapeutic drug, has adverse effects on heart and kidney functions. Ficus Carica (fig) and extra virgin olive oil (EVOO) are natural sources which have antioxidant effects. This study investigated the synergistic effects of fig extract and EVOO against cardiac and renal damage induced by 5-FU. Forty rats were equally divided into five groups and treated with physiological saline (control), five intravenous injections of 5-FU (40 mg/kg b.w) (5-FU), fig (1 g/kg b.w/day, orally) with 5-FU (Fig/5-FU), EVOO (7 g/kg b.w/day, orally) with 5-FU (EVOO/5-FU), combined treatment of fig and EVOO with five 5-FU injections (Fig/EVOO/5-FU). After 30 days, blood and tissue samples (Heart and kidney) were collected to be used in the examinations. 5-FU significantly increased serum creatine kinase activity, renal biomarkers, cholesterol, triglycerides, C-reactive protein, tumor necrosis factor-α, and interleukin-1β as well as cardiac and renal lipid peroxides (malondialdehyde). Meanwhile, serum levels of immunoglobulins, interleukins (IL-10, IL-12), and antioxidants of heart and kidney tissues were significantly decreased in 5-FU group. It also downregulated cardiac and renal Bcl2, and upregulated cardiac troponin and renin gene expressions. As well, histological alterations clarified that 5-FU induced cardiac cell damage, distorted renal corpuscles and tubules, inflammatory cell infiltrations, and severe congestion and hemorrhage in the blood vessels. The treatment with fig and olive oil, especially the combined treatment, modulated the toxic effect of 5-FU on the heart and kidney. Our results revealed that fig extract and EVOO have a powerful antioxidant and many protective effects against cardiac and renal toxicity induced by 5-FU, especially when using fig and EVOO together as a combined treatment.

Effect of grinding and long-term storage on the toxicity of white snakeroot (Ageratina altissima) in goats

White snakeroot (Ageratina altissima) contains the putative toxin tremetone and can produce a disease called “trembles” or “milk sickness”. However the toxicity of tremetone has not been demonstrated in vivo. It has been reported that the plant is less toxic after drying and grinding. The objectives of these studies were to determine: 1) the toxic effect of grinding white snakeroot 4 months prior to dosing and, 2) the toxic effect of storing white snakeroot at ambient temperature for 5 years. Dried white snakeroot, ground 1 day, 1 month, and 4 months prior to dosing, was orally gavaged to goats at 2% of their body weight for up to 28 days or until they were minimally poisoned (minimal muscular weakness and increased serum creatine kinase (CK) activities). All four goats dosed with white snakeroot that had been ground 4 months previously and stored at room temperature were poisoned, became exercise intolerant, and had increased serum CK activities (>5600 U/ L). White snakeroot stored for 5 years was toxic as 3 of 5 dosed goats developed clinical disease within only 6 days of dosing even though approximately 80% of the tremetone in the plant had disappeared during the 5-year storage period. The results from this study demonstrate that previous grinding and extended storage did not significantly alter white snakeroot toxicity. The results also indicate that tremetone concentration is not the singular indicator of toxicity and that other white snakeroot toxins or toxic tremetone degradation products remain in dried, stored white snakeroot.

Prognostic markers in feline hepatic lipidosis: a retrospective study of 71 cats

Feline hepatic lipidosis (HL) is a common, potentially life-threatening disease resulting from prolonged anorexia and increased catabolism. This retrospective study included cats diagnosed with HL based on liver cytology or...

Human skeletal muscle type 1 fibre distribution and response of stress-sensing proteins along the titin molecule after submaximal exhaustive exercise.

Early responses of stress-sensing proteins, muscle LIM protein (MLP), ankyrin repeat proteins (Ankrd1/CARP and Ankrd2/Arpp) and muscle-specific RING finger proteins (MuRF1 and MuRF2), along the titin molecule were investigated in the present experiment after submaximal exhaustive exercise. Ten healthy men performed continuous drop jumping unilaterally on a sledge apparatus with a submaximal height until complete exhaustion. Five stress-sensing proteins were analysed by mRNA measurements from biopsies obtained immediately and 3h after the exercise from exercised vastus lateralis muscle while control biopsies were obtained from non-exercised legs before the exercise. Decreased maximal jump height and increased serum creatine kinase activities as indirect markers for muscle damage and HSP27 immunostainings on muscle biopsies as a direct marker for muscle damage indicated that the current exercised protocol caused muscle damage. mRNA levels for four (MLP, Ankrd1/CARP, MuRF1 and MuRF2) out of the five studied stress sensors significantly (p<0.05) increased 3h after fatiguing exercise. The magnitude of MLP and Ankrd2 responses was related to the proportion of type 1 myofibres. Our data showed that the submaximal exhaustive exercise with subject's own physical fitness level activates titin-based stretch-sensing proteins. These results suggest that both degenerative and regenerative pathways are activated in very early phase after the exercise or probably already during the exercise. Activation of these proteins represents an initial step forward adaptive remodelling of the exercised muscle and may also be involved in the initiation of myofibre repair.

Effects of traditional judo training session on muscle damage symptoms.

This study aimed to analyze the acute effects of a judo training session on muscle strength, delayed-onset muscle soreness (DOMS), and serum creatine kinase (CK) activity. Ten male judo athletes participated in this study and performed a 90-min traditional judo training session. The following measurements were performed before and 48 hours after the training: shoulder external/internal rotation isokinetic torque, countermovement jump (CMJ), DOMS, and blood draw for serum CK analysis. Student's t-test with significance level set at 5% and, effect size analysis were used. Significant reduction was found in jump height in the CMJ after the training session (2.9%; moderate effect; P=0.02). No significant differences were observed in any of the measures of shoulder external/internal rotation isokinetic torque (P>0.05). An increase of the serum CK (49.4%; moderate effect; P=0.01) and DOMS (20.6%; large effect; P=0.003) were noted after the training session when compared to baseline. Judo training session resulted in increased serum CK activity, and muscle soreness. The decrease of CMJ performance indicates impairment in the lower-limbs muscle power production. However, the lack of difference of shoulder external/internal rotation torque before and 48 hours after the training session may indicate that the interval was enough to recover the upper-limbs strength in judokas of this study. These markers of muscle damage can be used to control muscle adaptation progress and to avoid sports-related disorders of athletes with similar characteristics to those evaluated in this study.

Muscular dystrophy in a family of Labrador Retrievers with no muscle dystrophin and a mild phenotype

Animal models of dystrophin deficient muscular dystrophy, most notably canine X-linked muscular dystrophy, play an important role in developing new therapies for human Duchenne muscular dystrophy. Although the canine disease is a model of the human disease, the variable severity of clinical presentations in the canine may be problematic for pre-clinical trials, but also informative. Here we describe a family of Labrador Retrievers with three generations of male dogs having markedly increased serum creatine kinase activity, absence of membrane dystrophin, but with undetectable clinical signs of muscle weakness. Clinically normal young male Labrador Retriever puppies were evaluated prior to surgical neuter by screening laboratory blood work, including serum creatine kinase activity. Serum creatine kinase activities were markedly increased in the absence of clinical signs of muscle weakness. Evaluation of muscle biopsies confirmed a dystrophic phenotype with both degeneration and regeneration. Further evaluations by immunofluorescence and western blot analysis confirmed the absence of muscle dystrophin. Although dystrophin was not identified in the muscles, we did not find any detectable deletions or duplications in the dystrophin gene. Sequencing is now ongoing to search for point mutations. Our findings in this family of Labrador Retriever dogs lend support to the hypothesis that, in exceptional situations, muscle with no dystrophin may be functional. Unlocking the secrets that protect these dogs from a severe clinical myopathy is a great challenge which may have important implications for future treatment of human muscular dystrophies.

A retrospective evaluation of Vipera palaestinae envenomation in 18 cats: (2006-2011).

To describe the clinical signs, clinicopathologic abnormalities, treatment, complications and outcome, and to identify risk factors for death in cats envenomed by Vipera palaestinae (Vp). Retrospective study. Veterinary teaching hospital. Eighteen client-owned cats envenomed by Vp. None. All envenomations occurred during the hot season (May to October), mostly in young (<4 years, 66%) domestic shorthair, outdoor or indoor-outdoor cats. Clinical signs included tachypnea (>40/min, 100%), lameness (78%), depression (71%), fang penetration marks (55%), hypothermia (<37.5°C, 43%), hematoma at the envenomation site (27%), tachycardia (>220/min, 20%), and bradycardia (<140/min, 20%). Hematologic abnormalities included thrombocytopenia (89%), hemoconcentration (33%), and leukocytosis (33%). The activated partial thromboplastin and prothrombin times were prolonged in 100% and in 93% of the cats at presentation to a veterinarian, and remained prolonged 12-24 hours later in 92% and in 77% of the cats, respectively. Cats displayed increased serum creatine kinase activity (100%) and hyperglycemia (89%). Four cats (22%) did not survive. Median hospitalization time was 2 days. Variables associated with death included lower body weight (P = 0.01), lower initial rectal temperature (P = 0.02), lower initial hematocrit (P < 0.001) and 12-24 hours later (P = 0.001), and lower total plasma protein at 12-24 hours following presentation (P = 0.001). There was no association between death and administration of antivenom (10 mL/cat), fresh frozen plasma, or corticosteroids. Cats are at least as susceptible as dogs to Vp envenomation. Lower body weight, rectal temperature, and hematocrit at presentation were associated with nonsurvival.

Clinical spectrum of psychiatric patients with rhabdomyolysis

Objective Rhabdomyolysis is a potentially life-threatening syndrome that can develop from various causes. This study was undertaken to analyse the clinical spectrum and to evaluate the prevalence of various aetiologies in psychiatric patients with rhabdomyolysis. Methods We retrospectively analysed the medical charts of 87 patients. For them, serum creatine kinase (SCK) activity higher than 1500 IU/l was defined as rhabdomyolysis. The causes of increased SCK activity were assessed. Results The annual incidence of rhabdomyolysis during 2007–2012 was 0.8–1.45%. In 59 men and 28 women (17–87 years old; median 50.9 years), no relation was found between age and the highest value of SCK activity. Their SCK activities were 1544–186 500 IU/l (median 3566 IU/l), but 45% had SCK activity higher than 5000 IU/l. Men were at greater risk than women. Major aetiologic factors were medical drugs, excessive physical activity, and psychogenic polydipsia. Patients with psychogenic polydipsia and alcoholism had higher SCK activity. Acute kidney injury (AKI) occurred in 8 men (9.1%). Five patients died, but only one died of rhabdomyolysis. Conclusions Most psychiatric patients with rhabdomyolysis were asymptomatic. The increase in SCK activity subsided spontaneously without specific treatment.

Severe Myositis Associated with Sarcocystis spp. Infection in 2 Dogs

Dogs are definitive hosts for numerous species of the intracellular protozoan parasite Sarcocystis. Reports of sarcocysts in muscles of dogs most often represent incidental findings. To report the clinicopathologic, ultrastructural, and molecular findings in 2 dogs with myositis associated with Sarcocystis spp. infection, as well as the response to treatment with antiprotozoal drugs. Two dogs with severe myositis in association with massive sarcocystosis. Retrospective case review. Affected dogs were identified by a diagnostic laboratory. Attending clinicians were contacted, and the medical records reviewed. Immunostaining and electron microscopy were performed on muscle biopsies. Biopsies also were subjected to 18S rRNA gene PCR. Both dogs had fever, lymphopenia, thrombocytopenia, and increased serum alanine aminotransferase (ALT) activity when first evaluated. One dog developed hyperbilirubinemia. Subsequently, both dogs had increased serum creatine kinase activity and clinical signs of myositis, with reluctance to move, generalized pain, and muscle wasting. Histopathology of muscle biopsies showed severe inflammatory and necrotizing myopathy with numerous sarcocysts. Ultrastructural studies and 18S rRNA gene sequence results were consistent with infection with a Sarcocystis spp. other than Sarcocystis neurona. Both dogs initially were treated unsuccessfully with clindamycin and anti-inflammatory drugs. One dog died. The other dog subsequently responded to treatment with decoquinate. Sarcocystis spp. infection should be included in the differential diagnosis for dogs that develop fever, thrombocytopenia, increased liver enzyme activities, and clinical and biochemical evidence of myositis. Although additional studies are required, decoquinate holds promise as an effective treatment for the disease.

Tick toxicosis in a dog bitten by Ornithodoros brasiliensis

Ticks are hematophagous parasites of people and animals and are a public health hazard in several countries. They are vectors of infectious diseases; in addition, the bite of some ticks, mainly from the Ornithodoros genus, may lead to local lesions and systemic illness, referred to as tick toxicosis. In this report, we describe a dog bitten by Ornithodoros brasiliensis, popularly known as the mouro tick. The main clinical findings were disseminated skin rash, pruritus, mucosal hyperemia, lethargy, and fever. Laboratory abnormalities 48 hours after the bites occurred included mild nonregenerative anemia, eosinophilia, basophilia, increased serum creatine kinase activity, increased serum C-reactive protein concentration, and prolonged coagulation times. Tick-borne pathogens were not detected by PCR analysis or serologic testing, supporting the diagnosis of a noninfectious syndrome due to tick bite, compatible with tick toxicosis.

Dissociation in changes in EMG activation during maximal isometric and submaximal low force dynamic contractions after exercise-induced muscle damage

Exercise induced muscle damage (EIMD) is characterized by muscle pain, symptoms of swelling, muscle shortening, increased serum creatine kinase activity, decreased force output and altered neuromuscular function. The aim of this study was to determine how the symptoms of EIMD influence the neuromuscular recruitment patterns during maximal and submaximal isometric and submaximal flexion–extension movements. Twenty-five right-handed males were recruited for this study, and were allocated to a control (n=13) or experimental group (n=12). In contrast to the control group, the experimental group participated in an EIMD protocol. Subsequently, symptoms of both groups were closely monitored for 132h. After the EIMD protocol, muscle pain scores in the experimental group peaked after 36h with creatine kinase activity peaking after 108h. Twelve hours after the EIMD protocol, EMG activity had decreased by 20% during a maximal voluntary contraction in the experimental group and decreased by a further 10% until the end of the study was reached 132h after the EIMD protocol. In contrast EMG during a submaximal flexion–extension movement increased significantly until the end of the study (132h). This dissociated EMG activity at submaximal and maximal intensity, suggests that central regulation influences the neural firing patterns and motor unit activity.

Retrospective Study of Salinomycin Toxicosis in 66 Cats

We examined 66 cats with salinomycin intoxication. Salinomycin caused different LMN signs of varying degrees of severity in all cases. Changes in blood work were unspecific, with the most frequent being increased serum creatine kinase activity, leukocytosis, and increased liver enzymes. Pathological electrodiagnostic findings: fibrillation potentials and positive sharp waves were detected in 10 cases, motor nerve conductance velocity was mildly decreased in 8/12 cats, and sensory nerve conductance velocity and repetitive nerve stimulation were normal in all examined cases. In five cases the peripheral neuropathy was confirmed by pathohistology. Fluid therapy and supportive care were used as therapy and 52 cats recovered completely. The probability for complete remission was significantly different between mildly and severely affected cases. It seems that the severity of clinical signs and prognosis correlate well with the amount of toxin ingested. We conclude that early recognition and decontamination combined with supportive care results in complete recovery.

Lymphoma‐Associated Polymyositis in Dogs

Lymphoma‐Associated Polymyositis in Dogs

Hemolysis, myopathy, and cardiac disease associated with hereditary phosphofructokinase deficiency in two Whippets

Two male castrated Whippet littermates were presented at 1 year of age for pallor, tachycardia, systolic heart murmur, dark yellow to orange feces, intermittent lethargy, pigmenturia, and muscle shivering or cramping after exercise. Persistent macrocytic hypochromic anemia with marked reticulocytosis and metarubricytosis was found when CBC results were compared with reference values for Whippets. Increased serum creatine kinase activity and hyperkalemia also were sometimes present over the 4-year period of evaluation. Progressively increasing serum concentrations of N-terminal prohormone brain natriuretic peptide suggested cardiac disease. Erythrocytes from the whippets were less osmotically fragile but more alkaline fragile than those from control dogs. Erythrocyte phosphofructokinase (PFK) activities and 2,3-diphosphoglycerate concentrations were decreased. Restriction enzyme-based DNA test screening and DNA sequencing revealed the same mutation in the muscle-PFK gene of the Whippets as seen in English Springer Spaniel dogs with PFK deficiency. This is the first report of PFK deficiency in Whippet dogs. In addition to causing hemolysis and exertional myopathy, heart disease may be a prominent clinical component of PFK deficiency in this breed and has not been previously recognized in PFK-deficient English Springer Spaniels.

Prevalence of increased serum creatine kinase activity due to macro-creatine kinase and experience of screening programmes in district general hospitals

Macro creatine kinase type 1 (MCK1) may be the cause of elevated total serum CK activity, which can lead to diagnostic confusion. There is evidence that this problem is poorly recognized perhaps due to a lack of information on its prevalence. Precipitation with polyethylene glycol (PEG) has been described for the detection of MCK1 but has not been fully evaluated. We introduced a screening programme to detect elevated serum total CK due to MCK1 and determine the prevalence of this problem using PEG precipitation with confirmation by gel filtration chromatography (GFC). The results were compared with those from a laboratory which selected samples for further investigation during the clinical validation process. We also studied characteristics of the PEG precipitation test including sensitivity and specificity when compared with GFC. Over 2 years we screened 368 patients. In 17 cases the proportion of CK activity precipitated by PEG was relatively high and the presence of MCK1 was confirmed in seven by GFC. In a second laboratory, over a period of 5 years, 11 samples were selected during the clinical validation process for further study and MCK1 was the cause of the elevated CK activity in six cases. PEG precipitates a proportion of normal, uncomplexed CK and this is increased by increasing serum globulin concentration and by higher concentrations of PEG. The prevalence of elevated serum CK activity due to MCK1 was approximately 2%. Laboratories should consider introducing a systematic screening programme based on PEG precipitation.

Myotonic dystrophy in two European grey wolves ( Canis lupus )

Two related European Grey wolves (Canis lupus) with the history of muscle stiffness beginning at 2 weeks of age were examined in this study. Muscle tone and muscle mass were increased in both animals. Muscle stiffness was worsened by stress so that the animals fell into lateral recumbency. Blood chemistry revealed mildly increased serum creatine kinase activity. Abnormal potentials typical of myotonic discharges were recorded by electromyography. Cataract, first-degree atrioventricular (AV) block and inhomogeneous myocardial texture by ultrasound suggested extramuscular involvement. Myopathology demonstrated dystrophic signs in the muscle biopsy specimen. The presumptive diagnosis based on the in vivo findings was myotonic dystrophy. Immunochemistry of the striated muscles revealed focal absence of dystrophin 1 and beta-dystroglycan in both cases. Cardiac and ophthalmologic involvement suggested a disorder very similar to a human form of myotonic dystrophy. This is the first description of myotonic dystrophy in wolves.

Serum Creatine Kinase Activity Varies with Ovulatory Status in Regularly Exercising, Premenopausal Women

Background/Aims: The clinical complications associated with an unopposed estrogen environment and luteal phase defects observed in exercising women prompted the examination of the relationship of exercise and endogenous ovarian steroids with serum creatine kinase (CK) activity. Methods: Subjects (n = 34) were classified into three groups according to their exercise and menstrual status, sedentary and exercising ovulatory groups (SedOvul, ExOvul), and an exercising amenorrheic group (ExAmen). Daily urine samples were collected to assess urinary ovarian steroid exposure and menstrual status. Serum CK activity was assayed in each menstrual cycle of all subjects. Results: Exercise increased serum CK activity in all exercising subjects (p < 0.01), but the increase was greater in amenorrheic women compared to ovulatory women (SedOvul: 33.0 ± 3.4; ExOvul: 43.7 ± 4.1; ExAmen: 54.4 ± 3.6, p < 0.05). When the ovulatory women were further divided into those with normal steroid production (ExOvul subgroup) and those with a suppressed progesterone luteal phase environment (ExLPD), both the ExOvul (51.9 ± 5.4 IU/l) subgroup and ExAmen group had higher serum CK activity (p < 0.05) than the ExLPD (36.6 ± 5.2 IU/l) subjects or the sedentary controls. Conclusions: These data demonstrate the complex association between ovarian hormone status and the normal serum CK response to regular mechanical stress imposed by chronic exercise training.