Vascular Wall PO2 Following Carbon Monoxide Exposure
Cigarette smoking and atherosclerosis may be linked to vascular wall damage caused by carbon monoxide (CO), nocotine or exposure to other toxic substances. Vascular wall hypoxia may play an important role in this process. Schneiderman and Goldstick (1,2) have simulated the effect of CO exposure on O2 transport to the wall of the human thoracic aorta using a computer model. The wall of the thoracic aorta and other large blood vessels must depend on O2 supply from both the vessel lumen and from the microvasculature of the outer wall (vasa vasorum). A two layer tissue model was chosen to represent the vascular wall in their analysis, with the tissue properties (O2consumption rate, Q, diffusivity, D, and solubility, K) for each layer estimated from the literature. The location and value of the minimum PO2 (Pmin) in the wall will depend on these tissue properties, as well as the wall dimensions and boundary conditions at the inner endothelial and outer adventitial edges of the a vascular portion of the wall. The computer studies indicate that Pmin will decrease with increasing levels of carboxyhemoglobin (COHb) within the range experienced by heavy smokers (up to 20%). Their model predicts that the middle or inner medial layer is most susceptible to hypoxic damage.
KeywordsThoracic Aorta Vascular Wall Outer Wall Vessel Lumen Hypoxic Damage
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- 3.Buerk, D. G., Hypoxia in the walls of large blood vessies, Ph.D. Thesis, Northwestern University, Department of Chemical Engineering, Evanston, II., 1980.Google Scholar
- 4.Buerk, D. G., Goldstick, T. K., Ernest, J. T. and Dobrin, P. B., Oxygen tension profiles and oxygen consumption inhomogeneities in the arterial wall: Implications for atherogenesis, Adv. in Physiol. Sci. 25: 23–24, 1981.Google Scholar
- 5.Roughton, F. J. W. and Darling, R. C., The effect of carbon monoxide on the oxyhemoglobin dissociation curve, Am. J. Physiol 141: 17–31, 1944.Google Scholar
- 8.Severinghaus, J. W., Blood gas calculator, J. Appl. Physiol 21: 1108–1116, 1966.Google Scholar
- 12.Sylvester, J. T. et al, Hypoxic and CO hypoxia in dogs: henodynamics, carotid reflexes and catecholamines, Am. J. Physiol.236: H22–28,.979.Google Scholar
- 16.Buerk, D. G. and Goldstick, T. K., An evaluation of the importance of the vasa vasorum for oxygenation of vascular wall tissue in vivo, Microvas, Res. 21: 238, 1981.Google Scholar