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The evolving paradigm for blood cell-endothelial cell interactions in the cerebral microcirculation.Microcirculation (New York, N.Y. : 1994) 2007Inflammation and microvascular dysfunction have been implicated in a variety of pathologic conditions affecting the brain. Features of the inflammatory response that are... (Review)
Review
Inflammation and microvascular dysfunction have been implicated in a variety of pathologic conditions affecting the brain. Features of the inflammatory response that are common to many of these pathological conditions and that are manifested in the neurovasculature include oxidative stress, diminished endothelial barrier function (increased vascular permeability), increased expression of endothelial cell adhesion molecules, and the recruitment of rolling and adherent leukocytes and platelets. The evidence implicating leukocyte-endothelial cell adhesion in cerebral microvessels as a rate-determining component of the pathophysiology associated with conditions such as ischemia-reperfusion, sickle cell disease, and gamma -irradiation is summarized. Mechanisms that have been proposed to explain the recruitment of adherent leukocytes and platelets in the diseased/injured cerebral microvasculature are also addressed, and a common paradigm for blood cell recruitment induced by seemingly unrelated pathological conditions is outlined. Although there are many structural and functional characteristics of the cerebral microvasculature that distinguish it from other regional vascular beds, the processes that underlie the recruitment of injury-causing inflammatory cells in the brain appear to closely resemble those described for other tissues.
Topics: Animals; Blood Cells; Cell Communication; Cerebrovascular Circulation; Cerebrovascular Disorders; Endothelium, Vascular; Humans; Microcirculation
PubMed: 17885993
DOI: 10.1080/10739680701404903 -
Clinical Science (London, England :... Aug 1996
Review
Topics: Animals; Cardiovascular Diseases; Endoscopy; Humans; Microcirculation
PubMed: 8795435
DOI: 10.1042/cs0910131 -
Cardiovascular Toxicology 2002Oxidative stress occurs when the production of reactive oxygen species (ROS) exceeds the capacity of the cell to detoxify these potentially injurious oxidants using... (Review)
Review
Oxidative stress occurs when the production of reactive oxygen species (ROS) exceeds the capacity of the cell to detoxify these potentially injurious oxidants using endogenous antioxidant defense systems. Conditions associated with oxidative stress include ischemia/reperfusion, hypercholesterolemia, diabetes, and hypertension. The adhesion of circulating blood cells (leukocytes, platelets) to vascular endothelium is a key element of the pro-inflammatory and prothrombogenic phenotype assumed by the vasculature in these and other disease states that are associated with an oxidative stress. There is a growing body of evidence that links the blood cell endothelial cell interactions in these conditions to the enhanced production of ROS. Potential enzymatic sources of ROS within the microcirculation include xanthine oxidase, NAD(P)H oxidase, and nitric oxide synthase. ROS can promote a pro-inflammatory/prothrombogenic phenotype within the microvasculature by a variety of mechanisms, including the inactivation of nitric oxide, the activation of redox-sensitive transcription factors (e.g., nuclear factor-kappaB) that govern the expression of endothelial cell adhesion molecules (e.g., P-selectin), and the activation of enzymes (e.g., phospholipase A(2)) that produce leukocyte-stimulating inflammatory mediators (e.g., platelet-activating factor). The extensively documented ability of different oxidant-ablating interventions to attenuate blood cell endothelial cell interactions underscores the importance of ROS in mediating the dysfunctional microvascular responses to oxidative stress.
Topics: Animals; Blood Cells; Cell Communication; Endothelium, Vascular; Humans; Microcirculation; Oxidative Stress
PubMed: 12665663
DOI: 10.1007/s12012-002-0002-7 -
Vrachebnoe Delo May 1984
Review
Topics: Arterioles; Blood Coagulation; Capillaries; Capillary Permeability; Hemodynamics; Humans; Lung; Lung Diseases; Microcirculation; Pulmonary Circulation; Respiration
PubMed: 6377698
DOI: No ID Found -
The Australian and New Zealand Journal... Jun 1977The microcirculation is an important but little understood part of the cardiovascular system. As new techniques have been developed, more accurate information has become...
The microcirculation is an important but little understood part of the cardiovascular system. As new techniques have been developed, more accurate information has become available concerning the changes in the microcirculation in both health and disease. A review has been made of some of the more important facets of the microcirculation of particular interest to surgeons. Reference is made to basic physiology, especially the mechanisms controlling flow in the microcirculation. The significance of changes in small blood vessels in hypovolaemic, septic, and progressive shock is also discussed, and the role of platelet aggregation in shock states is explored.
Topics: Animals; Arterioles; Diabetic Angiopathies; Disseminated Intravascular Coagulation; Humans; Lung; Microcirculation; Platelet Aggregation; Respiratory Distress Syndrome; Shock; Sympathetic Nervous System; Venules
PubMed: 269716
DOI: 10.1111/j.1445-2197.1977.tb04316.x -
Journal of Pharmacological Sciences Nov 2003Activity of blood cells, erythrocytes, leucocytes, and platelets, in microcirculation was observed by using an intravital microscope and confocal laser scanning... (Review)
Review
Activity of blood cells, erythrocytes, leucocytes, and platelets, in microcirculation was observed by using an intravital microscope and confocal laser scanning microscope connected with an image processing system including fluorescence and phosphorescence emission methods. Dynamic functions of the blood flow were mainly observed in mesentery, brain, and liver tissues of rats. The results are summarized as follows: Deformability of diabetic erythrocytes was significantly lower than that of healthy controls, particularly at high shear rate. The spring constant and Young's modulus of diabetic erythrocytes obviously stiffened, making them hard to deform in the capillary. During hemorrhagic shock and thrombosis, flow velocity and oxygen partial pressure of blood decreased in the brain and liver tissues that can be visualized by using FITC stained erythrocytes and Pd-porphyrin derivative as a pO(2) probe. Platelet adhesion and thrombus formation in the micro-vessels accelerated under the photodynamic reaction; diabetic platelets showed augmented adhesion and aggregation on the vessel wall which was followed by acute thromboembolism. Active oxygen radicals take part in thrombus formation, accompanied with adhesion of the activated leucocytes. Fluorescent dye probes, rhodamine G and acridine orange, are quite useful for visualization of the flow behavior of platelets and leucocytes, respectively.
Topics: Animals; Blood Flow Velocity; Diagnostic Imaging; Humans; Microcirculation; Optics and Photonics; Regional Blood Flow
PubMed: 14646237
DOI: 10.1254/jphs.93.227 -
Deutsche Medizinische Wochenschrift... Nov 2006
Review
Topics: Diagnostic Imaging; Humans; Leukocytes; Microcirculation; Monitoring, Physiologic; Multiple Organ Failure; Radiography; Regional Blood Flow; Severity of Illness Index; Shock, Septic
PubMed: 17066363
DOI: 10.1055/s-2006-955038 -
American Journal of Physiology. Heart... Nov 2004
Topics: Animals; Blood Pressure; Capillary Permeability; History, 20th Century; Microcirculation; United States
PubMed: 15475524
DOI: 10.1152/classicessays.00018.2004 -
Drugs 1999The recent arrival of new techniques for exploring the coronary microcirculation has facilitated assessment of both the incidence and consequences of disorders of this... (Review)
Review
The recent arrival of new techniques for exploring the coronary microcirculation has facilitated assessment of both the incidence and consequences of disorders of this network in a large number of cardiovascular diseases. The microcirculation is affected in numerous cardiomyopathies in the presence of different cardiovascular risk factors and also following cardiac transplantation. Dysfunction of the microcirculation may correspond to a reduction in the surface of the maximum section of coronary arterioles, which involves multiple mechanisms, although this phenomenon does not appear to play a role in ischaemic heart disease. Reduced coronary flow is most frequently related to vascular rarefaction of multifactorial origin, including greater or lesser degrees of intimal proliferation, perivascular fibrosis, hypertrophy of the media and extrinsic compression.
Topics: Cardiovascular Diseases; Coronary Circulation; Humans; Microcirculation
PubMed: 10526955
DOI: No ID Found -
Annals of the New York Academy of... 1989
Review
Topics: Animals; Cerebrovascular Circulation; Microcirculation; Regional Blood Flow; Thyrotropin-Releasing Hormone; Vasoconstriction; Vasodilation
PubMed: 2497679
DOI: 10.1111/j.1749-6632.1989.tb46657.x