Changes in the properties of plasma fibronectin in Shigella-induced endotoxaemia and the responses to hyperbaric oxygenation and indomethacin.

: In rabbits, Shigella endotoxin causes hypoxaemia, metabolic acidosis, and hypocapnia. These changes are more marked at a dose of 1 mg kg-1 than with one of 0.5 mg kg-1 body weight. The endotoxin also reduces the plasma level and heparin-binding activity of fibronectin (FN). During convalescence, FN activity recovers at a slower rate than its level. Hyperbaric oxygenation (HBO; 2 atm for 1 h) normalizes blood gas composition and acid-base and electrolyte balance, improves the clinical picture of endotoxaemia, enhances FN activity and, to a lesser degree, its concentration, and lowers mortality. Indomethacin (IN) (5 mg kg-1 orally) has a similar action. When HBO and IN are used in combination, there is no enhancement of the therapeutic effect and mortality increases.