Effect of acidosis and hypoxia on intestinal blood flow of sheep fetus.

In sheep fetuses 110-130 days of age acidosis (blood pH 6.95; produced by infusion with 1.1 M lactic acid) significantly lowered blood flow (ml/min/100g) to the full thickness wall of the jejunum from 135 +/- 11 to 93 +/- 14 and in the full thickness wall of the ileum from 122 +/- 13 to 95 +/- 11. The decrease was mainly due to the decline in blood flow to mucosa of the segment, where flow decreased from 182 +/- 20 to 83 +/- 14 in the jejunum and from 130 +/- 10 to 107 +/- 9 in the ileum. Fetal hypoxemia (PaO2 of 14.9 mm Hg; induced by allowing ewes to breath 11.1% O2 and 88.9% nitrogen) reduced blood flow only to the jejunal mucosa from 142 +/- 14 to 99 +/- 16. The reduction in blood flow to the full thickness wall of the jejunum and the ileum did not change significantly from the control period, when PaO2 was 25 mm Hg.