Salutary effects of a splenic factor in acute hemorrhagic shock

We have previously described the protective effects of a lipoidal splenic factor (SF) in mice challenged with E coli endotoxin. Whether SF would prove protective in hemorrhagic shock was the subject of the present study. Anesthetized and heparinized Sprague-Dawley rats were bled to a mean arterial pressure of 30 mm Hg. Pressure was maintained at this level for 90 minutes after which all blood was returned to the animals. Control animals received saline (1 ml) IP and the experimental animals SF (10 mg/kg) IP in an equal volume of saline as the controls one hour before bleeding. The 24-hour survival of the controls was 12% (3/25), whereas that of the SF recipients was 67% (4/6) (P less than 0.01). The exact mechanisms by which SF is protective in hemorrhagic shock remain to be determined.