Muscle contraction, analysis

Piascik MT, Hrometz SL, Edelmann SE, Guarino RD, Hadley RW, Brown RD. Immunocytochemical localization of the a1B adrenergic receptor and the contribution of this and the other subtypes to vascular smooth muscle contraction analysis with selective ligands and antisense oligonucleotides. J Pharmacol Exp Ther 1997 283 854-868. 

Description of Method. Creatine is an organic acid found in muscle tissue that supplies energy for muscle contractions. One of its metabolic products is creatinine, which is excreted in urine. Because the concentration of creatinine in urine and serum is an important indication of renal function, rapid methods for its analysis are clinically important. In this method the rate of reaction between creatinine and picrate in an alkaline medium is used to determine the concentration of creatinine in urine. Under the conditions of the analysis, the reaction is first-order in picrate, creatinine, and hydroxide. 

Parry, D. A. D., and Squire, J. M. (1973). The structural role of tropomyosin in muscle regulation Analysis of the X-ray diffraction patterns from relaxed and contracting muscles. /. Mol. Biol. 37, 33—55. 

Eight members of the myosin gene family have been Identified by genomic analysis (Chapter 9). Three family members—myosin I, myosin II, and myosin V—are present In nearly all eukaryotic cells and are the best understood. Although the specific activities of these myosins differ, they all function as motor proteins. As already noted, myosin II powers muscle contraction, as well as cytokinesis. Myosins I and V take part In c rt oskeleton-membrane interactions, such as the transport of membrane vesicles. 

The specific system that we use to explore these questions is the conventional myosin, also termed myosin 11, which plays key physiological functions in muscle contraction and cell division. It is an ideal system for in-depth theoretical and computational analysis because its structural and kinetic properties have been characterized by a large body of diverse experimental techniques." For example, at the time our research was initiated, myosin 11 was one of the few motor systems for which high-resolution x-ray structures are available for multiple functional states " since then, multiple high-resolution x-ray structures have also been obtained for myosin V and VI, two other widely studied members of the myosin superfamily that are more processive in nature compared to myosin 11. The functional cycle of myosin 11 is best described by the celebrated Lymn-Taylor schane (Figure 2.1a)," in which... 

Description of muscle contraction has essentially evolved into two separate approaches — lumped whole muscle models and specialized crossbridge models of the sarcomere. The former seek to interpret muscle s complex mechanical properties with a single set of model elements. Muscle experiments measure muscle force and length subjected to isometric (fixed length) conditions, isotonic (fixed load) conditions, and transient analysis where either length or load is rapidly changed. 

Palladino, J.L. and Noordergraaf, A. 1998. Muscle contraction mechanics from ultrastructural dynamics. In Analysis and Assessment of Cardiovascular Function, G.M. Drzewiecki and J.K.-J. Li, Eds., Springer-Verlag, New York, chap. 3, pp. 53-57. 

Raman spectroscopy is equally suitable for the analysis of gases, liquids, fibres, single crystals, surface features, etc. Intact measurements permit one to investigate the native molecular structure in biopolymers, living and other systems. It permits studies of eye lenses, the end processes of muscle contraction, components of living cells, and of ancient manuscripts and art objects, etc. The crystallinity of polymeric materials and orientation effects in fibres, monitored by FT-Raman spectra, could be very useful in technological control and in forensic science. 

Thromboxanes, TX derivatives of the Prostaglandins (see). T. induce aggregation of platelets, formation of clots and smooth muscle contraction. TXA2 is more active than TXBj, but it decays so rapidly (Fig.) that experimental analysis is difficult. TXB2 does not cause an increase in platelet cAMP levels (in contrast to the prostaglandins), while TXAj inhibits the increase of platelet cAMP caused by prostaglandins. 

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