A Study of Hepatic Injury Induced by Endotoxin in Rats.
- Author:
Dong Wha LEE
1
;
Chung Sook KIM
;
Yoo Bock LEE
;
Dong Sik KIM
Author Information
- Publication Type:Original Article
- MeSH: Acid Phosphatase/metabolism; Animal; Endotoxins*; Injections, Intraperitoneal; Liver/enzymology; Liver/pathology*; Liver Diseases/chemically induced; Liver Diseases/metabolism; Liver Diseases/pathology*; Male; Necrosis; Rats
- From:Yonsei Medical Journal 1978;19(2):19-34
- CountryRepublic of Korea
- Language:English
- Abstract: To study the mechanism of endotoxin-induced hepatocellular injury in rats, a single dose of endotoxin, 15mg/kg, was injected intraperitoneally with or without dexamethasone pretreatment. Studies included light microscopic, histochemical, and electron microscopic observations with concomitant assay of free acid phosphatase activity of liver homogenateg. The results showed an increase of acid phosphatase activity as early as 30 minutes after the injection of endotoxin, and by light microscopy random focal necrosis of liver cells at 1 hour and fibrin thrombi formation in sinusoids especially within the area of necrosis at 3 hours. However, ultrastructural alteration was noted as early as 5 minutes after the injection of endotoxin characterized by marked dilatation of RER. The degree of necrosis, fibrin thrombus formation, and the elevation of free acid phosphatase activity in the liver homogenates seemed to parallel each other suggesting a possible interrelationship among these phenomena. However, the ultrastructnral changes of the hepatocytes were present far ahead of the appearance of fibrin thrombi formation. Therefore, the causal relationship of the fibrin thrombi to liver cell injury appeared unlikely. Despite the increase of free acid phosphatase activity in liver homogenates, no demonstrable structural disruption of lysosomal membrane was noted. In view of the prominent changes of RER 5 minutes after the endotoxin administration, the primary injurious effect of endotoxin affects the membrane system of all organelles including the lysosomal membrane, leading to the leakage of lysosomal enzymes into the cytoplasmic sap. Dexamethasone pretreatment alleviated necrosis and markedly inhibited fibrin thrombus formation, and the mechanism of this effect is considered to be a stabilizing effect of glucocorticoid upon membrane systems.
