TY - JOUR
T1 - Neonatal intestinal oxygen consumption during arterial hypoxemia
AU - Edelstone, D. I.
AU - Lattanzi, D. R.
AU - Paulone, M. E.
AU - Holzman, I. R.
PY - 1983
Y1 - 1983
N2 - In 12 chronicaly catheterized neonatal lambs, we determined intestinal tract blood flow (Q̇(i)) and O2 consumption (V̇O2(i) at O2 contents of arterial blood (Ca(O2)) ranging from 15.3 to 3.2 ml O2/dl blood. We measured Q̇(i) with the radioactive microsphere technique and computed intestinal O2 delivery (DO2(i), V̇O2(i) and O2 extraction (V̇O2(i)/DO2(i) using the Fick principle. In lambs breathing air, mean Q̇(i) = 214 ml.min-1.100 g intestine-1, DO2(i) = 27.0 ml O2.min-1.100 g-1, O2 extraction = 21%, and V̇O2(i) = 5.6 ml O2.min-1.100 g-1. During reductions in Ca(O2), Q̇(i) and DO2(i) decreased. Intestinal O2 extraction increased sufficiently, however, so that V̇O2(i) was maintained over the range of CaO2 from 15.3 to about 6.5 ml O2/dl blood. V̇O2(i) was independent of Q̇(i) at Q̇(i) > 160 ml.min-1.100 g-1. When CaO2 was reduced below values of 6.5 ml O2/dl blood, corresponding to Q̇(i) < 160 ml.min-1.100 g-1, V̇O2(i) fell in association with increases in the H+ concentration difference between mesenteric venous and arterial blood. These data indicate that the intestinal tract of the neonatal lamb can meet its oxygen requirements when O2 supply varies over a wide range. When O2 availability reaches a critically low level, intestinal anaerobic metabolism develops as the O2 supply to the neonatal intestinal tract becomes inadequate for the O2 demand.
AB - In 12 chronicaly catheterized neonatal lambs, we determined intestinal tract blood flow (Q̇(i)) and O2 consumption (V̇O2(i) at O2 contents of arterial blood (Ca(O2)) ranging from 15.3 to 3.2 ml O2/dl blood. We measured Q̇(i) with the radioactive microsphere technique and computed intestinal O2 delivery (DO2(i), V̇O2(i) and O2 extraction (V̇O2(i)/DO2(i) using the Fick principle. In lambs breathing air, mean Q̇(i) = 214 ml.min-1.100 g intestine-1, DO2(i) = 27.0 ml O2.min-1.100 g-1, O2 extraction = 21%, and V̇O2(i) = 5.6 ml O2.min-1.100 g-1. During reductions in Ca(O2), Q̇(i) and DO2(i) decreased. Intestinal O2 extraction increased sufficiently, however, so that V̇O2(i) was maintained over the range of CaO2 from 15.3 to about 6.5 ml O2/dl blood. V̇O2(i) was independent of Q̇(i) at Q̇(i) > 160 ml.min-1.100 g-1. When CaO2 was reduced below values of 6.5 ml O2/dl blood, corresponding to Q̇(i) < 160 ml.min-1.100 g-1, V̇O2(i) fell in association with increases in the H+ concentration difference between mesenteric venous and arterial blood. These data indicate that the intestinal tract of the neonatal lamb can meet its oxygen requirements when O2 supply varies over a wide range. When O2 availability reaches a critically low level, intestinal anaerobic metabolism develops as the O2 supply to the neonatal intestinal tract becomes inadequate for the O2 demand.
UR - http://www.scopus.com/inward/record.url?scp=17644446766&partnerID=8YFLogxK
U2 - 10.1152/ajpgi.1983.244.3.g278
DO - 10.1152/ajpgi.1983.244.3.g278
M3 - Article
C2 - 6829768
AN - SCOPUS:17644446766
SN - 0193-1857
VL - 7
SP - G278-G283
JO - American Journal of Physiology - Gastrointestinal and Liver Physiology
JF - American Journal of Physiology - Gastrointestinal and Liver Physiology
IS - 3
ER -