IMPACT OF HYPERBARIC OXYGENATION ON RENAL AMMONIA EXCRETION DURING EXPERIMENTAL LIVER RESECTION

P N Savilov,D V Molchanov

doi:10.15360/1813-9779-2015-2-56-63

Abstract

Objective: to study the impact of hyperbaric oxygenation (HBO) on renal ammonia excretion during liver resection (LR). Material and methods. Experiments were carried out on 138 pubescent rats (females). Three HBO sessions were performed at 3 ATA lasting 50 min once daily after LR (15—20% of the liver weight). The kidney, blood (aorta, v. renalis), and urine were examined. The levels of ammonia, glutamine, and urea were measured. Results. By eliminating postoperative arterial hyperammonemia, HBO stimulates urinary ammonia ion excretion. This is achieved through elimination of the inhibitory effect of LR under HBO on ammonia secretion into the renal tubules and through activation of intracellular ammoniagenesis in nephrocytes, including that uncoupled with arterial glutamine deamidation. HBO potentiates simultaneously the activating effect of LR on the glutamine cycle in the kidneys mainly through the hyperproduction of renal glutamine and its influx from them into the bloodstream. HPO enhances the stimulatory effect of LR on urea reabsorption in the kidneys, but, unlike non-oxygenated rats, there was no reduction in urine urea excretion due to increased arterial blood urea concentrations. Termination of the body's exposure to hyperoxia restores urea reabsorption in the kidneys with the persisting stimulatory impact of HBO on the formation of urea by nephrocytes and its incretion from the latter into the bloodstream.

Highlights

Цель исследования — изучение влияние гипербарической оксигенации (ГБО) на аммиакэкскретирующую функцию по чек при резекции печени (РП)
Data analysis shows that the increased ammonia ions excretion with urine, being one of the mech anisms for regulation of ammonia concentration in kid neys, does not prevent ammonia accumulation on day 3 following hepatectomy rather participating in ammonia concentration reduction by 36% on day 14 following surgery (Tablе 1)
Comparison of ammonia and glutamine kinetics in kidneys following hepatectomy makes it possible to suggest and increase in deamidation by nephrocytes of other amino acids like glutamine participating in gluconeogenesis

Summary

Introduction

Цель исследования — изучение влияние гипербарической оксигенации (ГБО) на аммиакэкскретирующую функцию по чек при резекции печени (РП). ГБО проводили в режиме 3 ата, 50 мин, трехкратно, один сеанс в сутки после РП (15—20% от массы органа). В условиях ГБО усиливается стимулирующее влияние РП на реабсорбцию в почках мочевины, но, в отли чие от неоксигенированных крыс снижения экскреции мочевины с мочой не происходит, благодаря увеличению концен трации мочевины в артериальной крови. Objective: to study the impact of hyperbaric oxygenation (HBO) on renal ammonia excretion during liver resection (LR). By eliminating postoperative arterial hyperammonemia, HBO stimulates urinary ammonia ion excretion. HPO enhances the stimulatory effect of LR on urea reabsorption in the kidneys, but, unlike non oxygenated rats, there was no reduction in urine urea excretion due to increased arterial blood urea concentra tions. 1 серия — интактные живот ные (норма); 2, 3, 4 серии — животные исследованные, соот ветственно, на 3 и, 7 е и 14 е сутки после РП. Эти серии слу жили контролем для выявления «чистого» эффекта ГБО. 5, 6, 7 серии — оксигенированные животные с РП, исследован ные соответственно на 1 е, 4 е, 11 е сутки постгипероксиче ского (3 и, 7 е, 14 е сутки послеоперационного) периода

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