SYNTHESIS OF FIBRONECTIN BY THE ISOLATED PERFUSED-RAT-LIVER

  • 1 January 1982
    • journal article
    • research article
    • Vol. 59  (6) , 1305-1309
Abstract
The major site(s) of synthesis of plasma fibronectin is unknown. Using the isolated perfused rat liver and anti-rat fibronectin antiserum, net hepatic synthesis of fibronectin during 10-h perfusion periods was measured. The circulating plasma fibronectin pool of a 195-g rat with body surface area of 300 cm2 was calculated to be 3.3 mg; net hepatic synthesis of 3.75 .+-. 1.0 mg/300 cm2 body surface area of the rat liver donor was seen in liver perfusions of 10 h. When the hormones cortisol and insulin were added to the liver perfusate, net synthesis of 5.05 .+-. 0.82 mg/300 cm2 was seen. Synthesis of 2 known acute phase reactant proteins, fibrinogen and .alpha.-2 acute phase globin, was also substantially greater in the presence of cortisol and insulin. Plasma fibronectin levels measured in intact rats that had abscess produced by s.c. turpentine injection were 0.57 .+-. 0.05 mg/ml compared to 0.38 .+-. 0.02 mg/ml in normal control animals. Hepatic synthesis apparently contributes substantially to the plasma fibronectin pool; such synthesis is enhanced by the hormones cortisol and insulin. In the intact rat, inflammation was associated with elevated levels of plasma fibronectin.