Excretion of Ammonia and Urea by the Kidneys after Liver Resection and Hyperbaric Oxygenation

The objective of the study is to examine the impact of hyperbaric oxygenation (HBO) on ammonia excretion by kidneys in case of hepatectomy. Materials and methods. Experiments were conducted on 138 mature (female) rats. HBO was conducted at 3 atm during 50 minutes (three times), one session daily after hepatectomy (15-20% of the organ weight). Test objects were kidneys, blood (aorta, v.renalis), urine. The concentration of ammonia, glutamine, and urea were identified. Results. By eliminating post-surgery arterial hyperammonemia, HBO stimulates ammonia ions excretion with urine. It is a result of HBO's eliminating the inhibiting impact of hepatectomy on ammonia secretion into renal tubules and intracellular ammoniogenesis activation in nephrocytes, also not associated with “arterial” glutamine deamidation. At the same time HOT improves the activating hepatectomy impact on glutamine cycle in kidneys primarily due to increase in “renal glutamine” formation and its release into the blood flow. HOT increases the stimulating activity of hepatectomy on urea reabsorbtion in kidneys, but in contrast to non-oxygenated rats there is reduction in urea excretion with urine, due to the increase in urea concentration in arterial blood. Termination of hyperoxic activity over the body restores urea reabsorbtion in kidneys, with HOT stimulating activity over urea formation by nephrocytes and its release into the blood flow being preserved.