[Adequate hepatic circulation during induced hypotension].

The effects of prostaglandin E1 (PGE1) on the hepatic circulation was investigated in an extreme situation during acute hemorrhagic hypotension. Eighteen mongrel dogs were divided into two groups of those who received intravenous injection of PGE1 (PGE1 group, n = 9) and those who received control solution (non-PGE1 group n = 9). After anesthetizing dogs with 50% nitrous oxide in oxygen and 0.5% halothane, surgical procedure was carried out. Mean arterial pressure decreased to 50 mmHg by acute exsanguination, and this pressure was maintained by either saline (2.4 ml.kg-1 x h-1) or PGE1 (0.2 microgram.kg-1 x min-1) infused continuously for 2 hours. In dogs, PGE1 maintained the total hepatic blood flow with increased cardiac index and decreased splanchnic vascular resistance, in spite of the decreased mean arterial blood pressure during hemorrhagic hypotension. The result suggests that, in a hypotensive condition PGE1 may be useful in maintaining adequate hepatic circulation.