The kidney of chicken adapts to chronic metabolic acidosis: In vivo and in vitro studies
| Autor: | André G. Craan, Guy Lemieux, Patrick Vinay, André Gougoux, with the technical assistance of Andrée Quenneville |
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| Rok vydání: | 1982 |
| Předmět: |
medicine.medical_specialty
Glutamine In Vitro Techniques Biology Kidney Kidney Function Tests Ammonium Chloride Excretion Feces Ammonia Internal medicine Glutamine synthetase medicine Animals Infusions Parenteral Acidosis Alanine Glutamate dehydrogenase Feces analysis Chronic metabolic acidosis Kidney metabolism Acidosis Renal Tubular beta-Galactosidase Uric Acid Kidney Tubules Endocrinology Liver Nephrology medicine.symptom Chickens |
| Zdroj: | Kidney International. 22:103-111 |
| ISSN: | 0085-2538 |
| Popis: | The kidney of chicken adapts to chronic metabolic acidosis: In vivo and in vitro studies. Renal adaptation to chronic metabolic acidosis was studied in Arbor Acre hens receiving ammonium chloride by stomach tube 0.75 g/kg/day during 6 days. During a 14-day study, it was shown that the animals could excrete as much as 60% of the acid load during ammonium chloride administration. At the same time urate excretion fell markedly but the renal contribution to urate excretion (14%) did not change. During acidosis, blood glutamine increased twofold and the tissue concentration of glutamine rose in both liver and kidney. Infusion of L-glutamine led to increased ammonia excretion and more so in acidotic animals. Glutaminase I, glutamate dehydrogenase, alanine aminotransferase (GPT), and malic enzyme activities increased in the kidney during acidosis but phosphoenolpyruvate carboxykinase (PEPCK) activity did not change. Glutaminase I was not found in the liver, but hepatic glutamine synthetase rose markedly during acidosis. Glutamine synthetase was not found in the kidney. Renal tubules incubated with glutamine and alanine were ammoniagenic and gluconeogenic to the same degree as rat tubules with the same increments in acidosis. Lactate was gluconeogenic without increment during acidosis. The present study indicates that the avian kidney adapts to chronic metabolic acidosis with similarities and differences when compared to dog and rat. Glutamine originating from the liver appears to be the major ammoniagenic substrate. Our data also support the hypothesis that hepatic urate synthesis is decreased during acidosis. Le rein de poulet s'adapte a l'acidose metabolique chronique: Etudes in vivo et in vitro. L'adaptation renale a l'acidose metabolique chronique a ete etudiee chez des poulets Arbor Acre recevant 0,75 g/kg/j pendant 6 jours de chlorure d'ammonium par une sonde gastrique. Sur 14 jours, il a ete montre que les animaux pouvaient excreter jusqu'a 60% de la charge acide pendant l'administration du chlorure d'ammonium. En meme temps, l'excretion d'urates s'abaissait de facon marquee bien que la contribution du rein a l'excretion d'urates (14%) n'ait pas change. Pendant l'acidose, la glutaminemie a double et la concentration tissulaire de glutamine a augmente dans le foie et le rein. La perfusion de Lglutamine a augmente l'excretion d'ammoniaque surtout chez les animaux acidotiques. Les activites glutaminase I, glutamate deshydrogenase, alanine aminotransferase (GPT) et celle de l'enzyme malique se sont elevees dans le rein pendant l'acidose alors que l'activite phosphoenolpyruvate carboxykinase (PEPCK) ne s'est pas modifiee. Pendant l'acidose, il n'a pas ete trouve de glutaminase I dans le foie, mais la glutamine synthetase hepatique s'est considerablement elevee. Il n'a pas ete trouve de glutamine synthetase dans le rein. Des tubules renaux incubes avec de la glutamine et de l'alanine etaient capables d'ammoniogenese et de neoglucogenese avec la meme intensite que des tubules de rat avec une acidose identique. Le lactate etait neoglucogenique sans augmentation au cours de l'acidose. Cette etude indique que le rein aviaire s'adapte a l'acidose metabolique chronique avec des similitudes et des differences par rapport au chien ou au rat. La glutamine provenant du foie parait etre le principal substrat ammoniogene. Nos donnees confirment egalement l'hypothese que la synthese hepatique d'urates est diminuee au cours de l'acidose. |
| Databáze: | OpenAIRE |
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