The effects of thy rotropin-releasing hormone (TRH) on survival time, hemodynamics, acid-base balance and subcellular structure of liver cells in canine severe hemorrhagic shock were studied. The results showed that: (1) TRH significantly elevated and maintained mean arterial pressure (MAP) of dogs during shock (MAP was 13.99 ? 0.62 kPa at 4 h after treatment vs 5.09? 105 kPa in control); (2) TRH significantly prolonged the survival time of dogs (alive/total = 4/5 vs 1/5); (3) TRH effectively maintained acid-base balance; and (4) TRH maintained the integrity of subcellular structure of the liver cells. These results suggest that TRH may reverse severe hemorrhagic shock.