In order to characterize ADP-ATP and creatine-creatine phosphate (Cr-CrP) shuttles a minimal mathematical model with two compartments and cyclic turnover of matter was designed. The 'mitochondrial' compartment contained 'ATP-synthase' and 'mitochondrial creatine kinase' (mitCK). The 'cytoplasmic' compartment consisted of 'ATPase', 'cytoplasmic creatine kinase' (cytCK) and an 'ADP-binding struct...

Imatinib, the treatment of choice for chronic myeloid leukemia, is generally well tolerated. We present here data from a retrospective analysis on metabolic abnormalities occurring during therapy which show increased creatine kinase, inverse creatine kinase-phosphate correlation, cholesterol and triglyceride values.

The NMR technique of magnetization transfer can be used to define intracellular reaction kinetics. In order to determine the relationship between ATP synthesis and flux through the creatine kinase reaction in the intact heart, we used this technique to measure flux through the creatine kinase reaction in the isolated, isovolumic rat heart at five levels of cardiac performance and oxygen consump...

As is well known, many animals, when deprived of vitamin E (cr-tocopherol), develop a paralysis of the voluntary muscles (1). The partly grown rabbit becomes completely helpless in 3 to 4 weeks. The progress of the disease is characterized by histological changes and alterations in chemical composition. Thus muscle creatine declines considerably (2), in rats even before any abnormality in struc...

An automated (AutoAnalyzer) method for the colorimetric determination of creatine kinase activity in serum is described. This method includes reactivation of creatine kinase with cysteine, incubation of the active enzyme with creatine phosphate and adenosine diphosphate at 3750, and subsequent inactivation of enzyme and binding of csteine by phenylmercuric borate. The enzymatically produced cre...

I have re-examined optimum reaction conditions for measurement of creatine kinase (EC 2.7.3.2). The optimum pH is 6.45, and 2,2-bis(hydroxymethyl)-2,2',2''-nitrotriethanol acetate, 200 mmol/liter, is the buffer of choice. Thioglycerol, 20 mmol/liter, is superior for both in-assay reactivation and for storage stability of sera. Fluoride, 25 mmol/liter, a broad inactivator of adenylate kinase (EC...

Ischemia-reperfusion generates peroxynitrite (ONOO-), which interacts with many of the systems altered by ischemia-reperfusion. This study examines the influence of endogenously produced ONOO- on cardiac metabolism and function. Nitro-L-arginine (an inhibitor of ONOO- biosynthesis) and urate (a scavenger of ONOO-) were utilized to investigate potential pathophysiological roles for ONOO- in a ra...

PSE, DCB and DFD meat are stress-related conditions. PSE meat occurs in pigs and turkeys. In pigs it is common in particular breeds which are known as stress-sensitive (SS) or halothane-positive (nn) genotypes. This chapter focuses on some of the key features in post-mortem muscle metabolism which lead to these meat quality problems, and so helps to explain how preslaughter stress influences me...

The effects of phosphate depletion (PD) of 4, 8, and 12 weeks on skeletal muscle energy metabolism were studied in rats fed a phosphate deficiency diet and compared with rats pairfed with a normal phosphate diet. Skeletal muscle biopsy specimens were examined for energy production, transport, and utilization. The results show that already by 4 weeks of PD, the concentration of inorganic phospho...

PURPOSE The effects of creatine supplementation on muscle metabolism and exercise performance during a simulated endurance road race was investigated. METHODS Twelve adult male (27.3 +/- 1.0 yr, 178.6 +/- 1.4 cm, 78.0 +/- 2.5 kg, 8.9 +/- 1.1 %fat) endurance-trained (53.3 +/- 2.0 ml* kg-1* min-1, cycling ~160 km/wk) cyclists completed a simulated road race on a cycle ergometer (Lode), consisti...