[Profiles next to the walls of the rat cerebral arterioles and venules in acute anemia].
Acute anemia was shown to result in increase of pO2 in the wall of radial arterioles (with lumen diameter of 14.7 +/- 0.9 microm) and in the tissue near the studied arterioles, while decreasing as compared to control values at the distance 60 urn from the vessel wall. Hypoxic tissue zones were not manifested even in severe anemia near the studied arterioles. In radial venules (with lumen diameter of 13.1 +/- 0.5 microm) acute anemia (steps 1-2) resulted in decrease in pO2 in the wall and in tissue at 40 microm from the wall, indicating substantial O2 extraction from the blood of the minute microvessels. There were no significant changes in tissue pO2 profiles near the studied venules during steps 2-3 in acute normovolemic hemodilution. The intercapillary tissue pO2 fell proportionally to hemoglobin concentration in systemic blood, while tissue hypoxia (p(t)O2 < 8--10 mm Hg) was present only in tissue microzones nearest to the microvessels with impaired responses of the blood flow to the anemic stimuli.
Vovenko
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EP
Chuĭkin
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D000208:Acute Disease; D000740:Anemia / Q000503:physiopathology*; D000818:Animals; D001160:Arterioles / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D006454:Hemoglobins / Q000502:physiology; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000502:physiology; D055806:Microvessels / Q000503:physiopathology*; D010100:Oxygen / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014699:Venules / Q000503:physiopathology*
D006454:Hemoglobins; D010100:Oxygen