Effects of Bacterial Endotoxin on Some Metabolites and Enzymes in Rat Serum

The effects of bacterial endotoxins (Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium) on glucose and blood urea nitrogen (BUN) levels and aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and lactate dehydrogenase (LDH) activities were studied. Three groups of rats were injected (1 mg/kg body weight, i.p.) with three types of bacterial endotoxins (E. coli, K. pneumoniae and S. typhimurium) as a single dose. The control group was injected i.p. (1 mg/kg) in 0.9% normal saline. Blood sampling was performed from the orbital vein plexus after 24 and 72 hr of injection. Glucose level was increased significantly after 24 hr of after each 3 solutions of endotoxin. Its level showed non-significant decrease after 72 hr post-treatment. However, endotoxins caused significant increases in BUN, ASAT and LDH at 24 and 72 hr post-treatment. On the other hand, the ALAT activity was significantly decreased after the referred observation periods of endotoxins injection. The variation in serum glucose level after 24 and 72 hr post-treatment may be referred to different reasons. On the other hand, the increase of BUN concentration may be due to the toxic effect of bacterial endotoxins resembling to that occurring in renal damage and impairment of renal function. However, the changes in serum aminotransferases and LDH activities may be due to endotoxins induced hepatic microcirculatory disturbance and to the subsequent liver injury and tissue hypoxia.