AHEART April 47/4
نویسندگان
چکیده
Osterloh, Kurt, Peter Gaehtgens, and Axel R. Pries. Determination of microvascular flow pattern formation in vivo. Am J Physiol Heart Circ Physiol 278: H1142–H1152, 2000.—Blood flow in microvessels differs significantly from that of red blood cells (RBC) flowing through long, straight glass tubes in vitro. The in vivo situation is characterized by the presence of plasma favoring aggregation, by the irregular geometry of vessel segments, and by frequent branching points. Here, a method is presented to characterize flow patterns in microvascular blood flow during intravital microscopy based on Fourier analysis of recorded light intensity patterns. The interpretation of the resulting power spectra in terms of pattern size distribution was validated by model experiments employing artificial textures and by reverse transformation of idealized spectra. The determined size of RBC flow patterns in microvessels ranged from ,8 μm in capillaries to ,14 μm in vessels of .30 μm. With increasing shear rate above ,100 s21 pattern size increased, possibly reflecting formation of short-lived flow clusters. Below ,100 s21 an increase of pattern size with decreasing shear rate was found in experiments using local occlusion and treatment with high-molecular-weight dextran, suggesting the formation of aggregates. The dynamic process of generation and destruction of RBC flow patterns could well contribute to flow resistance in vivo in peripheral vascular beds.
منابع مشابه
AHEART April 47/4
Munzenmaier, Diane H., and David R. Harder. Cerebral microvascular endothelial cell tube formation: role of astrocytic epoxyeicosatrienoic acid release. Am J Physiol Heart Circ Physiol 278: H1163–H1167, 2000.—Cerebral microvascular endothelial cells (CMVEC) form tubes when cocultured with astrocytes (AS). Therefore, it appears that AS may be important in mediating angiogenesis in the brain. We ...
متن کاملAHEART April 47/4
Wang, Yan, and Yoram Rudy. Action potential propagation in inhomogeneous cardiac tissue: safety factor considerations and ionic mechanism. Am J Physiol Heart Circ Physiol 278: H1019–H1029, 2000.—Heterogeneity of myocardial structure and membrane excitability is accentuated by pathology and remodeling. In this study, a detailed model of the ventricular myocyte in a multicellular fiber was used t...
متن کاملAHEART February 47/2
DAVID FULTON,1 ANDREAS PAPAPETROPOULOS,1 XIAOPING ZHANG,2 JOHN D. CATRAVAS,3 THOMAS H. HINTZE,2 AND WILLIAM C. SESSA1 1Department of Pharmacology, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536-0812; 2Department of Physiology, New York Medical College, Valhalla, New York 10595; and 3Vascular Biology Center and Department of Pharmacology and...
متن کاملAHEART April 47/4
Kuoppala, Antti, Ken A. Lindstedt, Juhani Saarinen, Petri T. Kovanen, and Jorma O. Kokkonen. Inactivation of bradykinin by angiotensin-converting enzyme and by carboxypeptidase N in human plasma. Am J Physiol Heart Circ Physiol 278: H1069–H1074, 2000.—Because bradykinin (BK) appears to have cardioprotective effects ranging from improved hemodynamics to antiproliferative effects, inhibition of B...
متن کاملAHEART April 47/4
Landesberg, Amir, and Samuel Sideman. Force-velocity relationship and biochemical-to-mechanical energy conversion by the sarcomere. Am J Physiol Heart Circ Physiol 278: H1274–H1284, 2000.—The intracellular control mechanism leading to the well-known linear relationship between energy consumption by the sarcomere and the generated mechanical energy is analyzed here by coupling calcium kinetics w...
متن کاملAHEART April 47/4
Frame, Mary D. Increased flow precedes remote arteriolar dilations for some microapplied agonists. Am J Physiol Heart Circ Physiol 278: H1186–H1195, 2000.—This study asks which occurs first in time for remote responses: a dilation or a remote change in flow. Arteriolar diameter (,20 μm) and fluorescently labeled red blood cell (RBC) velocity were measured in the cremaster muscle of anesthetized...
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