Biochemical abnormalities during the progression of hepatic fibrosis induced by dimethylnitrosamine

The pathogenesis of hepatic fibrosis is accompanied with several biochemical and metabolic abnormalities. To obtain more information about the alteration of biochemical and metabolic parameters during alcoholic liver fibrosis, we have monitored the changes of certain important biochemical compounds in experimentally induced hepatic fibrosis.

The liver injury was induced in adult male albino rats by using dimethylnitrosamine (DMN) in doses of 1 mg/100 g body weight. Total collagen, total protein, cholesterol, lipid peroxides, glucose, urea, and inorganic phosphorus were monitored in liver and blood/serum samples on Days 0, 7, 14, and 21 after the start of DMN administration. Serum insulin levels were assayed by radioimmunoassay. The serum and urinary levels of hydroxyproline, uric acid, and creatinine were also monitored.

The total collagen content in the liver was increased about 4-fold by Day 21 after the start of DMN administration. A significant increase was observed in lipid peroxide levels in both liver and blood samples. Although inorganic phosphorus level decreased in both serum and liver tissue, cholesterol was lowered only in the serum. Increased serum insulin level with impaired glucose tolerance was observed after 21 days. Serum hydroxyproline level increased throughout after the start of DMN administration. The urinary excretion of hydroxyproline was also significantly increased with a striking elevation on Day 7. Elevated uric acid levels were recorded in serum and urine samples during the latter periods of DMN treatment. No alteration was observed in blood urea and creatinine levels.

The results of the present investigation demonstrated important alterations in metabolic parameters and biochemical abnormalities during experimentally induced liver damage. All alterations are compatible with the deterioration of liver functions during the pathogenesis of hepatic fibrosis.