Effects of temperature on ileal blood flow and oxygenation.

Arterial pressure, venous outflow pressure, blood flow, and arteriovenous oxygen difference were measured in autoperfused preparations of canine ileum while lumen temperature was altered in 1-5 degrees C increments (or decrements) between 31 and 40 degrees C. Neither blood flow nor vascular resistance was correlated to lumen temperature. However, both arteriovenous oxygen difference and oxygen uptake were linearly correlated with lumen temperature. The relation between ileal oxygen uptake and lumen temperature was consistent with a change in metabolic rate for a 10 degrees C change in temperature (Q10) for oxygen consumption of 2.7. These observations indicate that ambient temperature exerts a profound influence on intestinal oxygen consumption and that variations in temperature may explain the wide range of intestinal oxygen uptake values reported in the literature.