Organ models cardiac

The reasons for this are diverse and include the fact that models of cardiac cellular activity were among the first cell models ever developed. Analytical descriptions of virtually all cardiac cell types are now available. Also, the large-scale integration of cardiac organ activity is helped immensely by the high degree of spatial and temporal regularity of functionally relevant events and structures, as cells in the heart beat synchronously. 

Cardiac models are amongst the most advanced in silico tools for bio-med-icine, and the above scenario is bound to become reality rather sooner than later. Both cellular and whole organ models have aheady matured to a level where they have started to possess predictive power. We will now address some aspects of single cell model development (the cars ), and then look at how virtual cells interact to simulate the spreading wave of electrical excitation in anatomically representative, virtual hearts (the traffic ). 

The above phenomena have a bearing on various physiological processes, e.g. membrane transport, oscillatory phenomena in cells and living organism, models for sense of taste and smell and flow system associated with cardiac rhythms. 

Physiologically Based Phamiacokinetic (PBPK) Model—Comprised of a series of compartments representing organs or tissue groups with realistic weights and blood flows. These models require a variety of physiological information tissue volumes, blood flow rates to tissues, cardiac output, alveolar ventilation rates and, possibly membrane permeabilities. The models also utilize biochemical information such as air/blood partition coefficients, and metabolic parameters. PBPK models are also called biologically based tissue dosimetry models. 

These may be produced by grouping together multiple cell models to form virtual tissue segments, or even the whole organ. The validity of such multi-cellular constructs crucially depends on whether or not they take into account the heart s fine architecture, as cardiac structure and function are tightly interrelated. 

Ischemia-reperfusion is thought to mediate the severe organ dysfunction witnessed after shock or cardiac arrest. HSPs could play a major role in the defence against ischemia-reperfusion injury. Many in vivo experimental models of ischemia and/or ischemia-reperfusion have demonstrated HSP induction. 

There have been several studies that underscore the importance of unbound concentration in cell-based studies of receptor function. In a model study of the effect of plasma protein binding on the renal transport of organic anions using the expression of various organic anion transporters (OATPs) in Xenopus oocytes, the transport of ochratoxin A, methotrexate, and estrone sulfate was found to be strongly inhibited by the addition of human serum albumin to the culture medium [16]. Similarly, the addition of oq-acid glycoprotein was found to reverse the blockade of sodium-ion current by cocaine in a preparation of cardiac myocytes [17]. 

Aconite alkaloids Aconitine, molecular formula C34H47NO11, is an example of an aconite alkaloid. It is soluble in organic solvents, e.g. CHCI3 and CeHg, and sfightly soluble in alcohol or ether, but insoluble in water. Aconitine is an extremely toxic substance obtained from the plants of the genus Aconitum (family Ranunculaceae), commonly known as aconite or monkshood . It is a neurotoxin, and used for creating models of cardiac arrhythmia. 

The one-compartment model of distribution assumes that an administered drug is homogeneously distributed throughout the tissue fluids of the body. For instance, ethyl alcohol distributes uniformly throughout the body, and therefore any body fluid may be used to assess its concentration. The two-compartment model of distribution involves two or multiple central or peripheral compartments. The central compartment includes the blood and extracellular fluid volumes of the highly perfused organs (i.e., the brain, heart, liver, and kidney, which receive three fourths of the cardiac output) the peripheral compartment consists of relatively less perfused tissues such as muscle, skin, and fat deposits. When distributive equilibrium has occurred completely, the concentration of drug in the body will be uniform. 

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