Small Blood Vessels

Anthocyanins help maintain microcapillary integrity by stabilizing the capillary walls. Blocked or reduced oxygen followed by the reestablishment of normal supplies is called ischemia-reperfusion . Ischemia-reperfusion could create the oxidants which result in white blood cell adhesion to the microcapillary walls, increase the capillary wall permeability, reduce the blood flow, and often cause permanent capillary damage. 

One of the classic experiments on anthocyanins was conducted on hamsters in Italy. Ischemia-reperfusion was created in the cheeks by a brief clamping, causing the white cells to clump onto the capillary wall and damage it. The administration of the bilberry supplementation for several weeks after the reperfusion could restore the normal blood supply through the capillaries, reducing the sticking of white blood cells to the vessel walls, and the permeability [15]. 

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The bioflavanoids (vitamin P complex) are substances which maintain the small blood vessel walls. The substances are widely distributed among plants, eg, all citms fmits, and have been used medicinally to decrease capillary permeability and fragility. 

Acetylchohne is a vasodilator that acts by causing relaxation of the smooth muscle of blood vessels. However, it does not act directly on smooth muscle. A key observation was that if endothefial cells were stripped away from underlying smooth muscle cells, acetylcholine no longer exerted its vasodilator effect. This finding indicated that vasodilators such as acetylcholine initially interact with the endothelial cells of small blood vessels via receptors. The receptors are coupled to the phos-phoinositide cycle, leading to the intracellular release of... 

A third type is a disseminated fibrin deposit in very small blood vessels or capillaries. 

Once having passed through the walls of small blood vessels, the neutrophils migrate toward the highest concentrations of the chemotactic factors, encounter the invading bacteria, and attempt to attack and destroy them. The neutrophils must be activated in order... 

Air embolus An obstruction in a small blood vessel caused by air that is introduced into a blood vessel and carried through the circulation until it lodges in a smaller vessel. 

Micro vascular pulmonary emboli An obstruction in the small blood vessels in the lung caused by material (e.g., blood clot, fat, air, and foreign body) that is carried through the circulation until it lodges in another small vessel. 

Petechiae Tiny localized hemorrhages from the small blood vessels just beneath the surface of the skin. 

Telangiectasia Permanent dilation of preexisting small blood vessels (capillaries, arterioles, and venules), usually in the skin or mucous membranes, which presents as a coarse or fine red mark. 

Deletion and derangement of small blood vessels Increase permeation to water and some chemicals Decrease clearance into blood stream Decrease absorption ... 

Location Attached to bones openings of some hollow organs (sphincters) Large blood vessels eyes hair follicles Walls of hollow organs of digestive, reproductive, and urinary tracts small blood vessels... 

A widely distributed fixed tissue cell, the mast cell, is particularly prevalent in organs with a high percentage of connective tissue [20] and is most numerous in the skin and in the linings of the respiratory, gastrointestinal and reproductive tracts, tissues which interface with the external environment. In these various locations, mast cells are frequently found in close proximity to small blood vessels and nerves [20]. This prominence of the mast cell in tissues that interface with the external world is strategic to its role as the sentinel cell of the... 

Figure 3. A detailed depiction of a tiny section (C in Figure 1) of this tumo11 showing tumor cells, interstitium, a small blood vessel and the route that a drug i the chemotherapeutic treatment takes. Adapted from Jain.45...

Vascular endothelial growth factor VEGE cells suffering from hypoxia endothelial cells of small blood vessels ... 

Histamine (B). Histamine is stored in basophils and tissue mast cells. It plays a role in inflammatory and allergic reactions (p. 72, 326) and produces bronchoconstriction, increased intestinal peristalsis, and dilation and increased permeability of small blood vessels. In the gastric mucosa, it is released from enterochromaffin-like cells and stimulates acid secretion by the parietal cells. In the CNS, it acts as a neuromodulator. Two receptor subtypes (G-pro-tein-coupled), H and H2. are of therapeutic importance both mediate vascular responses. Prejunctional H3 receptors exist in brain and the periphery. 

FFeart disease, particularly clogged blood vessels, is also treated with recombinant products. Alteplase (Activase ), a human recombinant protein that breaks down fibrin, is used immediately after a stroke or heart attack to break down platelet-trapping clots in small blood vessels of the heart or brain and thus improve the patient s chances for recovery. Purified enzymes from bacteria are used for the same purposes. Abciximab (ReoPro ), a monoclonal antibody to... 

Hi-receptors mainly mediate the constriction of large and relaxation of small blood vessels, contractions of the bronchial, intestinal and uterine smooth muscle and contractions of vascular endothelial cells with the result of an increased capillary permeability. The lymphatic flow is augmented by Hi-receptor stimulation. H2-receptor stimulation induce a dilatation of pulmonary arteries, a positive inotropic and chronotropic effect on the heart and an increased glandular secretion, especially in the mucosa of the stomach. 

Stimulants may be taken orally, but some abusers crush the tablets, dissolve them in water, and then inject the mixture complications can arise from this because insoluble fillers in the tablets can block small blood vessels. Stimulants have been abused for both performance enhancement and recreational purposes (i.e., to get high). 

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