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Biomedical subjects

T R Bennett

Publications and source records attributed to T R Bennett.

4 recordsLinked to original sources
PubMed1977

Survival in the fetal rabbit exposed to intermittent hypoxia.

To investigate the time course and mechanisms of fetal O2 deprivation, we exposed 93 near-term, pregnant rabbits and their fetuses in utero to intermittent hypoxia. We administered a gas mixture containing 3, 4, 5 or 6 per cent O2 in N2 to a rabbit for 0.5, 1, 2, or 3 minutes, alternately with a recovery period of air breathing of 0.5, 1, 2, or 3 minutes. A given cyclical pattern was continued for 2 hours and fetal survival recorded 1 hour thereafter. Fetal survival decreased significantly at lower O2 levels, longer durations of exposure, and shorter durations of recovery intervals between exposures. Chances for survival were significantly greater among fetuses located at either end of the uterine horn.

Animals↗
PubMed1975

Placental diffusing capacity in unanesthetized rabbits.

The purpose of this study was to determine the placental diffusing capacity of CO in unanesthetized rabbits. A standard dose of CO was administered to 18 near-term rabbits, and at time intervals varying from 5 min to 4 h maternal and fetal blood samples were analyzed for carboxyhemoglobin saturation (HbCO). Following administration of CO, the maternal HbCO rose rapidly within the 1st min and remained nearly constant for the remainder of the experiment. The fetal HbCO after CO introduction to the mother rose as CO crossed the placenta from maternal to fetal blood. After 15 min the fetal HbCO rose to equal the maternal HbCO averaging 18.5%. The fetal HbCO after 1 h averaged 33% saturation, 1.7-fold greater than the maternal HbCO at 1 h. Thereafter there was little further fetal rise and apparently equilibrium was reached. The average placental diffusing capacity for CO was 2.3 ml/(min times mmHg times kg), a value fourfold higher than has previously been reported in anesthetized sheep and dogs. Possible reasons are species difference, effects of posture, influence of anesthesia and surgery, and effects of an open versus intact uterus.

Animals↗