Tissues aorta

The data of Table 1 reveal very clearly that some tissues (aorta, trachea) show a clear distinction in sensitivity between agonist- and K+-induced responses whilst other tissues (ileum) show equisensitivity of K+-and agonist-induced responses. Similarly, marked differences in sensitivity to responses induced by the same agonist in different tissues are found (5-HT responses of rabbit saphenous and basilar arteries). 

Absorption coefficients of water and a typical human tissue (aorta) as a function of wavelength. The suitable region for optical excitation is between 650 and 1000 nm. This figure is drawn using data from the Handbook on Industrial Laser Safety, http //info.tuwien.ac.at/iflt/safety/index.htm. 

BC suspension obtained from an agitation culture system was mixed with PVA powder to fabricate PVA-BC composite by considering PVA as a matrix and BC as a reinforcement material. The composite was proposed for cardiovascular soft tissue replacement application [78], The composite could be adjusted its mechanical properties to get close to those of specific tissue [aorta and heart valve] by changing the composition of the composite and the processing parameters. 

Thus it seems possible to conclude that for the type of lipids (cholesterol, free and ester, triglycerides and phospholipids) and tissues studied (liver, adipose tissue, aorta, adrenal, intestine, nervous tissue, and macrophages) no significant translocation of the labeled lipid was observed. 

Other surgical implants are essentially plastic repair products for worn out parts of the body. It is possible to conceive of major replacements of an entire organ such as a kidney or a heart by combining the plastic skills with tissue regeneration efforts that may extend life. This is used to time the heart action. Extensively used are plastic corrugated, fiber (silicone or TP polyester) braided aortas (24). 

Another example was done by Opitz et al. They utilized P4HB scaffolds to produce viable ovine blood vessels, and then implanted the blood vessels in the systemic circulation of sheep. Enzymatically derived vascular smooth muscle cells (vSMC) were seeded on the scaffolds both under pulsatile flow and static conditions. Mechanical properties of bioreactor-cultured blood vessels which were obtained from tissue engineering approached those of native aorta. 

They also seeded autologous vSMC and ECs obtained from ovine carotid arteries to study autologous tissue-engineering blood vessels in the descending aorta of juvenile sheep. They found that after three months implantation, grafts were fully patent, without dilatation, occlusion, or intimal thickening. A continuous luminal EC layer was formed. However, after six months ... 

Shum-Tim D, Stock U, Hrkach J, Shinoka T, Lien J, Moses MA, Stamp A, Taylor G, Moran A, Landis W, Langer R, Vacanti JP, and Mayer JE Jr. Tissue engineering of autologous aorta using a new biodegradable polymer. Ann Thorac Surg, 1999, 68(6), 2298-304. 

A relationship between polyol pathway activity and reduction in endothelium-dependent relaxation in aorta from chronic STZ-diabetic rats has recently been reported (Cameron and Cotter, 1992). In agreement with several previous studies (Oyama et al., 1986 Kamata et al., 1989), endothelial-dependent relaxation was defective in the diabetic rats but the deficit was prevented by prior treatment with an AR inhibitor. The mechanism underlying the defect has been speculated to be due to decreased production of endothelium-derived relaxing factor (EDRF) or nitric oxide, NO (Hattori et al., 1991). It has been speculated that these vascular abnormalities may lead to diminished blood flow in susceptible tissues and contribute to the development of some diabetic complications. NO is synthesized from the amino-acid L-arginine by a calcium-dependent NO synthase, which requires NADPH as a cofactor. Competition for NADPH from the polyol pathway would take place during times of sustained hyperglycaemia and... 

Humans may be exposed to hydrogen sulfide both from its endogenous production or from exogenous sources. Most endogenous production apparently results from the metabolism of sulfhydryl-containing amino acids, e.g., cysteine, by bacteria present in both the intestinal tract and the mouth (Beauchamp et al. 1994 Tonzetich and Carpenter 1971) however, it is also produced in the brain and several smooth muscles, e.g., thoraic aorta, by enzymes found in these tissues (Abe and Kimura 1996 Hosoki et al. 1997). 

The primary function of the heart is to deliver a sufficient volume of blood (oxygen and nutrients, etc.) to the tissues so that they may carry out their functions effectively. As the metabolic activity of a tissue varies, so will its need for blood. An important factor involved in meeting this demand is cardiac output (CO) or the volume of blood pumped into the aorta per minute. Cardiac output is determined by heart rate multiplied by stroke volume ... 

FIGURE 8.8 H2S production in vascular tissues. IPS production by aorta homogenate (upper panel), cultured rat vascular smooth muscle cells (VSMCs middle panel), and intact rat aorta occurs after the addition of substrate L-cysteine (L-cys) and cofactor pyridoxal L-phosphate (PLP) for the enzyme CGL located in vascular tissue. H2S production is inhibited after the CGL. 3 cyano-L-alanine (BCA) is added. Ferric Lucina pectinata hemoglobin I (metHb) is added to confirm H2S production. The quantity of metHb-sulfide produced, determined spectrophotometrically, matched the levels of H2S detected by the PHSS (after [41]). 

The same group drew similar conclusions from their findings with mtALDH [99]. Cyanamide and propionaldehyde, respectively an inhibitor and a substrate of ALDH, were shown to diminish GTN-induced relaxation to the same extent in aortic tissue from tolerant and non-tolerant animals. They reasoned that inhibition of relaxation caused by cyanamide or propionaldehyde in tolerant aortae could not be via further inhibition of mtALDH and was more likely to result from non-specific inhibition of GTN-induced relaxation. 

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