Evaluation of Serum and Urine Amino Acids in Dogs with Chronic Kidney Disease and Healthy Dogs Fed a Renal Diet.

Marcio Antonio Brunetto,Juliana Toloi Jeremias,Bruna Ruberti,Larissa Wunsche Risolia,Cristiana Fonseca Ferreira Pontieri,Doris Pereira Halfen,Julio César De Carvalho Balieiro,Douglas Segalla Caragelasco,Thiago Henrique Annibale Vendramini,Marcia Mery Kogika,Vivian Pedrinelli

doi:10.3390/metabo11120844

Marcio Antonio Brunetto, Juliana Toloi Jeremias + Show 9 more

Open Access

https://doi.org/10.3390/metabo11120844

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Abstract

This observational study aimed to evaluate serum and urinary amino acid (AA) concentrations in healthy dogs and dogs with chronic kidney disease (CKD) fed a commercial therapeutic renal diet with reduced protein and phosphorus levels. Ten dogs with CKD stages 3 or 4 composed the study group and received the renal diet for 180 days (RG T180). A control group (CG T30) composed of seven healthy dogs was fed a renal diet for 30 days. When comparing serum AA between RG T180 and CG T30, histidine, isoleucine, leucine, lysine, phenylalanine, tryptophan, cysteine, citrulline, ornithine, taurine, branched-chain amino acids (BCAA), and total essential amino acids (EAA) were higher in RG T180. Meanwhile, arginine, asparagine, aspartate, glutamine, serine, and tyrosine were higher in CG T30. Serum phenylalanine, tryptophan, and hydroxyproline were higher in RG T0 (dogs with CKD before consuming a renal diet) when compared to RG T180. In addition, the serum ratios of arginine/citrulline, tyrosine/phenylalanine, and serine/glycine were higher in CG T30 than in RG T180. Concerning urinary AA concentrations in CKD dogs, isoleucine, phenylalanine, tryptophan, aspartate, cysteine, and BCAA were higher in RG T180. In urine, the total EAA/total non-essential AA ratio in RG T180 was higher than in CG T30 as well as tyrosine/phenylalanine ratio higher in CG T30. In conclusion, the combination of renal diet and conservative treatment over 6 months in dogs with CKD stages 3 or 4 affected the AAs metabolism when compared to healthy adult dogs.

Highlights

Serum urea, creatinine, and phosphorus were higher in the renal group (RG) than control group (CG), as expected, but serum creatinine increased between RG T0 and RG T180
There were no differences between the groups for total calcium and ionized calcium, and there were no differences in RG at T0 and T180 regarding PTH and fibroblast growth factor 23 (FGF-23)
Lower concentrations of arginine, asparagine, aspartate, glutamine, serine, and tyrosine were observed in animals with chronic kidney disease (CKD) when compared to healthy animals

Summary

Introduction

Chronic kidney disease (CKD) is characterized by renal dysfunction of one or both kidneys for an extended period, usually 3 months or longer. Its classical clinical and laboratory manifestations usually present when approximately 70% of nephrons are compromised. The renal damage is irreversible and often progressive, and it is estimated that 0.5 to 1.6%. Of dogs are affected by this condition [1,2]. More recent data suggest that about 7 to 10% of dogs between 8 and 10 years present with elevated SDMA or SDMA and creatinine concentrations, and the prevalence increases with age [3]. CKD causes a decrease in glomerular filtration rate as well as retention of various substances that are normally excreted by the kidneys, such as nitrogenous compounds (uremic toxins) and phosphorus

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