Metabolismo da glutamina em caninos sadios e enfermos

Abstract

Glutamine (GLN) is produced in different tissues through the enzime glutamine synthetase (GS). Muscular tissue, due to its extensiveness, is the largest producer of this amino acid, followed by lungs, liver and placenta. Enterocytes and immune system cells are the largest consumers. During severe infections and diseases that produce catabolism, there is an elevated breakdown of GLN, which can be compensated, up to a certain point, by an increase in GS expression. To better a understanding of GLN metabolism in dogs, whether healthy or not, we envisioned this experiment which had the objective of determining the [GLN] and other blood metabolites associated with protein metabolism in healthy dogs, blood donors, with cancer or with severe diseases. Blood samples were collected from 133 animals, divided into four groups: healthy, with cancer, severe infectious disease, and blood donors. [Glutamine], [Glutamate], [Urea], [Creatinine], [Total Plasma Protein] (TPP), [Glucose], [Fibrinogen] and hematocrit were determined in each sample. The body score index (BSI) was also determined. The results were analyzed using ANOVA, with a significance level of P<0,05, and Tukey's test with post hoc, with P<0,05. The results indicate thAT was no statistical difference in BSI between the group with cancer and the healthy group (P<0,05), but there was a difference when these were compared to the blood donor and infectious disease groups (P>0,05), where the latter had lower IEC. [GLN] and [GLN+GLU] were significantly lower than in the healthy animals (P<0,05), where the groups with cancer, infectious diseases and blood donors had a reduction of ~82%, ~73% e ~88%, respectively in their [GLN]. We observed a significant elevation in [Creatinine] in the blood donors and infectious diseases groups when compared to the healthy animals (P<0,05). There were no differences in [Urea], [Fibrinogen] and [Glucose] between groups (P>0,05). The [TPP] had higher values in the group with cancer (P<0,05) and the hematocrit in the group with blood donors (P<0,05). We conclude that, in the groups with sick animals and blood donors, there is an elevated degradation of GLN, which might compromise its availability for the consumer tissues during the evolution of an illness, which in turn could make for a difficult recovery. Establishing a hygienic and dietary management through GLN supplementation can be an important nutritional support for sick animals or blood donors.