Leukocyte emigration

Springer TA. Traffic signals for lymphocyte recirculation and leukocyte emigration the multistep paradigm. Cell 1994 76 301-314. 

Springer, T. A. (1995). Traffic signals on endothelium for lymphocyte recirculation and leukocyte emigration. Traffic signals for lymphocyte recirculation and leukocyte emigration The multistep paradigm. Annu. Rev. Physiol. 57, 827-872. 

Chemokines A large family of cytokines having a wide variety of biological actions that are generally associated with inducing mobilization and activation of immune cells a contraction of chemotactic cytokines. See Atkins, PC. and Wasserman, S.I., Chemotactic mediators, Clin. Rev. Allergy 1, 385-395, 1983 Hayashi, H., Honda, M., Shimokawa, Y., and Hirashima, M., Chemotactic factors associated with leukocyte emigration in immune tissue injury their separation, characterization, and functional specificity. 

T. A. Springer, Traffic Signals for Lymphocyte Recirculation and Leukocyte Emigration the Multistep Paradigm, Cell 76 (1994) 301-314. 

Hurley, J.V. (1963). An electron microscopic study of leukocytic emigration and vascular permeability in rat skin. Aust. J. Exp. Biol. 41, 171-186. 

Springer, T. A. (1994) Traffic signak for lymphocytes recirculation and leukocytes emigration the multistep paradigm. G //76, 301-314. 

Springer TA Traffic signals on endothelium for lymphocyte recirculation and leukocyte emigration. Annu Rev Physiol 1995 57 827-872. 

Soderberg-Naucler C, Fish KN, Nelson JA (1997) Reactivation of latent cytomegalovirus by allogeneic stimulation of blood cells from healthy donors. Cell 91 119-126 Springer TA (1994) Traffic signals for lymphocyte recirculation and leukocyte emigration the multistep paradigm. Cell 76 301-314... 

Under in vivo conditions, an acute reduction of the inspired POj initiates a rapid microvascular response characterized by increased leukocyte-endothelial interactions, followed by leukocyte emigration into the interstitium and increased vascular permeability. An alteration in the balance between... 

ROS and NO appears to play a critical role in this phenomenon.In support, microvascular ROS levels (as assessed using oxidant-sensitive fluorescent probes) increased during hypoxia. Antioxidants attenuated the hypoxia-induced increase in ROS formation, leukocyte adherence, vascular permeability, and leukocyte emigration. Interventions designed to increase tissue levels of NO also attenuated these microvascular inflammatory responses during hypoxia. ... 

If hypoxia is maintained, the initial microvascular responses described previously eventually resolve. In the mesenteric and cremasteric microcirculations of rats exposed to a hypoxic environment for 3 weeks, measurements of leukocyte adherence, leukocyte emigration, and vascular permeabflity are not significantly different from values obtained in animals maintained in a normal oxygen environment (i.e., normoxic animals). The mechanisms responsible for the acclimatization of vascular endothelial function during sustained hypoxia are not yet clear. However, it is well known that chronic hypoxia leads to an increase in red blood cell mass in response to increased erythropoietin secretion. It is possible that the elevated hemoglobin concentration resulting from the increased red blood cells could improve oxygen delivery to tissues and attenuate the severity of hypoxia at the venular level. However, systemic hypoxia did not result in leukocyte adherence to mesenteric venules of acclimatized rats, even after the red blood cell concentration was reduced to normal values. ... 

In summary, exposure to environmental hypoxia promotes increased leukocyte-endothelial interactions characterized by increased leukocyte rolling and adherence to the vascular endotheKum, followed by leukocyte emigration and increased vascular permeability. This response is observed in several micro-circulatory beds, suggesting that it represents a generalized response to systemic hypoxia. After 3 weeks of continuous hypoxic exposure, the microvascular inflammatory response resolves, and the vascular endothelium is resistant to even lower POj levels. The initial microvascular response to hypoxia is... 

Wood, J.G., Johnson, J.S., Mattioli, L.E, and Gonzalez, N.C., Systemic hypoxia increases leukocyte emigration and vascular permeability in conscious rats, /. Appl Physiol, 89,1561, 2000. 

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