AJP - Regulatory, Integrative and Comparative Physiology, Vol 237, Issue 1 52-R57, Copyright © 1979 by American Physiological Society
O2 delivery to the pregnant uterus: its relationship to O2 consumption
D. Caton, C. Crenshaw, C. J. Wilcox and D. H. Barron
Normal sheep were studied at intervals of 3-5 days during the last weeks of
pregnancy in order to evaluate variability in rate of O2 consumption (QO2)
of the uterus in relation to several variables involved in delivery of O2
to the organ. Among-animal differences of uterine QO2 were statistically
significant and directly related to birthweight of the lamb. Among-animal
differences of uterine blood flow (UBF) and uterine arteriovenous O2
content difference [C(a-v)O2] also were statistically significant, though
neither was related to birthweight, presumably since they tended to vary
inversely with one another. In a given ewe relative magnitude of UBF and of
C(a-v)O2 was related to maternal arterial O2 content (CaO2), day of
pregnancy, and whether the animal carried singlets or twins. Variability in
QO2 was most closely related to UBF, although its relations to C(a-v)O2 and
CaO2 were significant also. These data suggest there are systematic
relationships among variables involved in the delivery of O2 to the uterus
of pregnant sheep.
