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participating readily in reactions; "sodium is a reactive metal"; "free radicals are very reactive"
reacting to a stimulus; "the skin of old persons is less reactive than that of younger persons" (同)responsive
increased blood in an organ or other body part (同)hyperaemia

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/03/20 18:32:32」(JST)

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Hyperaemia or hyperemia is the increase of blood flow to different tissues in the body. It can have medical implications, but is also a regulatory response, allowing change in blood supply to different tissues through vasodilation. Clinically, hyperaemia in tissues manifest as erythema, because of the engorgement of vessels with oxygenated blood.^[1] Hyperaemia can also occur due to a fall in atmospheric pressure outside the body.

Hyperaemia and the regulation of blood flow[edit]

Functional hyperaemia is an increase in blood flow to a tissue due to the presence of metabolites and a change in general conditions. When a tissue increases activity there is a well-characterized fall in the partial pressure of oxygen and pH, an increase in partial pressure of carbon dioxide, and a rise in temperature and the concentration of potassium ions. The mechanism for vasodilation is unclear, but it may have something to do with the opening of precapillary sphincter.

Functional hyperaemia[edit]

Functional hyperaemia, metabolic hyperemia or active hyperaemia, is the increased blood flow that occurs when tissue is active.

When cells within the body are active in one way or another, they use more oxygen and fuel, such as glucose or fatty acids, than when they are not. Increased metabolic processes create more metabolic waste. The byproducts of metabolism are vasodilators. (Vasodilating metabolites: CO2, H+, K+, lactate, adenosine) Local arterioles respond to metabolism by dilatating, allowing more blood to reach the tissue. This prevents deprivation of the tissue.

Conversely, when a tissue is less metabolically active, it produces fewer metabolites which are simply washed away in blood flow.

Since most of the common nutrients in the body are converted to carbon dioxide when they are metabolized, smooth muscle around blood vessels relax in response to increased concentrations of carbon dioxide within the blood and surrounding interstitial fluid. The relaxation of this smooth muscle results in vascular dilation and increased blood flow.

Some tissues require oxygen and fuel more quickly or in greater quantities. Examples of tissues and organs that are known to have specialized mechanisms for functional hyperaemia include:

The brain through the neuron-dependent haemodynamic response.
Penile erection tissue by release of nitric oxide.

Reactive hyperaemia[edit]

Reactive hyperaemia is the transient increase in organ blood flow that occurs following a brief period of ischaemia. Following ischaemia there will be a shortage of oxygen and a build-up of metabolic waste.

This is commonly tested in the legs using Buerger's test.

Reactive hyperaemia often occurs as a consequence of Raynaud's phenomenon, where the vasospasm in the vasculature leads to ischaemia and necrosis of tissue and thus a subsequent increase in blood flow to remove the waste products and clear up cell debris.

External links[edit]

Active and reactive hyperemia. Richard E. Klabunde, Ph.D. Cardiovascular Physiology Concepts. Accessed on 27 February 2006.

References[edit]

^ Jon Aster, Vinay Kumar, Abul K. Abbas; Nelson Fausto (2009). Robbins & Cotran Pathologic Basis of Disease (8th ed.). Philadelphia: Saunders. p. 113. ISBN 1-4160-3121-9.

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English Journal

Mineral intake independent from gastric irritation or pica by cell-dehydrated rats.

Constancio J, Pereira-Derderian DT, Menani JV, De Luca LA Jr.AbstractGavage of 2M NaCl (IG 2M NaCl), a procedure to induce cell-dehydration-and water and 0.15M NaCl intake in a two-bottle choice test-is also a potential gastric irritant. In this study, we assessed whether mineral intake induced by IG 2M NaCl is associated with gastric irritation or production of pica in the rat. We first determined the amount of mineral solution (0.15M NaCl, 0.15M NaHCO(3), 0.01M KCl and 0.05mM CaCl(2)) and water ingested in response to IG 2M NaCl in a five-bottle test. Then, we used mineral solutions (0.01M KCl and 0.15M NaHCO(3)), whose intakes were significantly increased compared to controls, and water in three-bottle tests to test the gastric irritation hypothesis. The IG 2M NaCl induced KCl and NaHCO(3) intake that was not inhibited by gavage with gastric protectors Al(OH)(3) or NaHCO(3). IG 2M NaCl or gavage of 0.6N acetic acid induced mild irritation, hyperemia, of the glandular part of the stomach. A gavage of 50% ethanol induced strong irritation seen as pinpoint ulcerations. Neither ethanol nor acetic acid induced any fluid intake. Neither IG 2M NaCl nor acetic acid induced kaolin intake, a marker of pica in laboratory rats. Ethanol did induce kaolin intake. These results suggest that IG 2M NaCl induced a mineral fluid intake not selective for sodium and independent from gastric irritation or pica.
Physiology & behavior.Physiol Behav.2011 Oct 24;104(5):659-65. Epub 2011 Jul 18.
Gavage of 2M NaCl (IG 2M NaCl), a procedure to induce cell-dehydration-and water and 0.15M NaCl intake in a two-bottle choice test-is also a potential gastric irritant. In this study, we assessed whether mineral intake induced by IG 2M NaCl is associated with gastric irritation or production of pica
PMID 21781982

Japanese Journal

乳酸菌生成ペプチドの血圧降下・血管機能改善作用

中村康則,大木浩司
腸内細菌学雑誌 = Journal of intestinal microbiology 24(4), 259-264, 2010-10-01
乳酸菌Lactobacillus helveticusは，発酵中に乳蛋白質を分解し，潜在するペプチドvalyl-prolyl-proline，isoleucyl-prolyl-prolineを産生する．両ペプチドは，アンジオテンシン変換酵素阻害活性を有する．この酵素は，アンジオテンシンIに作用し，強力な血圧上昇物質アンジオテンシンIIを産生することで知られる．動物実験および in vitro試験の …
NAID 10027792789