Lack of Response of Brain and Adrenal Blood Flow to Hypoxemia in the Fetal Llama

Abstract

The fetus of sheep a species that evolved in lowlands, responds to hypoxemia (H) by maintaining cardiac output and umbilical-blood flow, increasing heart, brain and adrenal blood flow and decreasingittoother organs. The response to H of the fetus of the llama, thas has evolved in high altitudes, is not fully understood. We postulate that the systemic responses to H in the fetal llama are less marked and that the main adaptation occurs at the cellular and tissue levels. Our aim was to compare cardiac output and its distribution at 0 min (B) and after 20 min of fetal H (22-27% Sathb and 3-6 m102/dl in descending aorta) in-8 fetal sheep and 8 fetal llamas at 0.8 gestation. The results (x t SEM) were: Fetal Llama Fetal Sheep Basal Hypoxernia Basal Hyp~xemia Cardiac output (ml/minxkg)