Cardiac and skeletal muscle

Myocardial gene expression of CK is developmentally regulated (Lamers et al., 1989 Hasselbaink et al., 1990). In the mouse BB-CK alone is expressed during prenatal development, until the last week, when MM-CK increases dramatically whilst the BB-CK isoform decreases concomitantly. Associated with the co-expression of M-CK and B-CK gene peripartum, and during the first 3 weeks postnatally, there is up to a maximum of 35 MB-CK activity (Hall and DeLuca, 1975 Ingwall, 1991). The mitochondrial...

Cardiovascular System

Creatine Phosphate in vivo Human Cardiac Metabolism Studied by Magnetic Resonance Spectroscopy 127 Michael A. Conway. Ronald Ouwerkerk. Bheeshma Rajagopalan and George K. Radda 2. The normal heart resting metabolism 128 3. The normal heart isotonic and isometric exercise 131 4. Left ventricular hypertrophy 137 5. Ischaemic heart disease 143 6. Myocarditis and dilated cardiomyopathy 148 7. Cardiac transplantation 149 8. Creatine phosphate changes in tachycardia and rhythm disorders 150 9....

Photoreceptors

Photoreceptor cells are among the most morphologically polarized cells. They subdivide into four distinct segments, each with different metabolic functions. The phototransduction events of the photic cycle occur in the outer segments. At the opposite end of the cell the highly elaborated nerve terminals synapse onto second-order neurons, between these two regions. The inner segments are packed with mitochondria and thus serve as the ATP-generating sites within the photoreceptors. In the retina...

Modulation and regulation of creatine transport

Little effect on creatine uptake rates has been observed with PCr, creatinine, ornithine, glycine, glutamic acid, histidine, alanine, arginine, leucine, methionine or cysteine (Fitch, 1988 Loike et al., 1988 M ller and Hamprecht, 1989). The sodium-dependent uptake of creatine in culture is sensitive to extracellular creatine concentration (Loike et al., 1988). Myoblasts maintained for 24 h in a medium containing 1 mM creatine exhibited one-third of the uptake activity of cells bathed for the...

Role Of Phosphagens In Clinic

Traditionally, phosphagens have been considered as a fuel available for the rapid rephosphorylation of ADP produced by the hydrolysis of ATP in processes such as muscle contraction. The significance of this role of phosphocreatine, for example to the athlete, is that, unlike ATP, it can be stored in the muscle, ready and available to rephosphorylate ADP in an instant The quantities are small though greater than the ATP (enough in leg muscle for perhaps 5 s of sprinting) but it can be used very...