Abstract
The responsiveness of the smallest blood vessels of the human skin was measured in systemic anoxemia, hypercapnia, acidosis, and alkalosis. A method was used which measured quantitatively the reactive hyperemia produced by a standardized period of local ischemia of these fine vessels. By timing the clearing period of the threshold hyperemia response a direct indication of blood flow in these fine vessels was obtained. The following conclusions were reached concerning the responses of the smallest blood vessels of the skin. 1. Systemic anoxemia causes a decrease in sensitivity to local ischemia and a slowing of the blood flow. 2. Hypercapnia prevents the changes resulting from anoxemia. 3. These changes in the smallest blood vessels of the skin occur independently of changes in pulse rate, blood pressure, and respiratory rate and depth. 4. With systemic acidosis there is a decrease in sensitivity to local ischemia and a slowing of blood flow. The exact opposite takes place in systemic alkalosis. 5. The view is advanced, after due consideration of the facts, that the carbon dioxide concentration of the blood, or something directly associated with it, is the most important factor determining the sensitivity of these vessels, rather than oxygen saturation or changes in blood pH.
Full Text
The Full Text of this article is available as a PDF (573.9 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Di Palma J. R., Reynolds S. R., Foster F. I. MEASUREMENT OF THE SENSITIVITY OF THE SMALLEST BLOOD VESSELS IN HUMAN SKIN: RESPONSES TO GRADED MECHANICAL STIMULATION IN NORMAL MEN. J Clin Invest. 1941 Jul;20(4):333–343. doi: 10.1172/JCI101227. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hemingway A., McDowall R. J. The chemical regulation of capillary tone. J Physiol. 1926 Dec 10;62(2):166–173. doi: 10.1113/jphysiol.1926.sp002348. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McConnell F. S., Weaver W. K., Alexander H. L. OBSERVATIONS ON THE FORMATION OF WHEALS: V. The Effects of Variation of the CO(2) Combining Power of the Blood on Histamine Wheals. J Clin Invest. 1932 Jan;11(1):205–209. doi: 10.1172/JCI100402. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rous P., Drury D. R. OUTLYING ACIDOSIS DUE TO FUNCTIONAL ISCHEMIA. J Exp Med. 1929 Feb 28;49(3):435–460. doi: 10.1084/jem.49.3.435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roy C. S., Brown J. G. The Blood-Pressure and its Variations in the Arterioles, Capillaries and Smaller Veins. J Physiol. 1880 Jul;2(5-6):323–446.1. doi: 10.1113/jphysiol.1880.sp000068. [DOI] [PMC free article] [PubMed] [Google Scholar]