Plasma and Erythrocyte Glutathione Peroxidase Activity, Serum Selenium Concentration, and Plasma Total Antioxidant Capacity in Cats with IRIS Stages I–IV Chronic Kidney Disease

Abstract

BackgroundSerum selenium concentrations and the activity of plasma glutathione peroxidase (GPx) decrease with the progression of chronic kidney disease (CKD) in human patients. Selenium is considered a limiting factor for plasma GPx synthesis. Plasma total antioxidant capacity (TAC) is decreased in CKD cats in comparison to healthy cats.HypothesisSerum selenium concentrations and plasma and erythrocyte GPx activity in cats with CKD are lower than in healthy cats. Serum selenium concentrations, the activity of enzymes, and plasma TAC progressively decrease with the progression of kidney disease according to IRIS (International Renal Interest Society) classification.AnimalsTwenty‐six client‐owned cats in IRIS stages I–IV of CKD were compared with 19 client‐owned healthy cats.MethodsA CBC, serum biochemical profile, urinalysis, plasma and erythrocyte GPx activity, serum selenium concentration, and plasma TAC were measured in each cat.ResultsCats in IRIS stage IV CKD had a significantly higher (P = .025) activity of plasma GPx (23.44 ± 6.28 U/mL) than cats in the control group (17.51 ± 3.75 U/mL). There were no significant differences in erythrocyte GPx, serum selenium concentration, and plasma TAC, either among IRIS stages I–IV CKD cats or between CKD cats and healthy cats.Conclusions and Clinical ImportanceErythrocyte GPx activity, serum selenium concentration, and plasma TAC do not change in CKD cats compared with healthy cats. Selenium is not a limiting factor in feline CKD. Increased plasma GPx activity in cats with stage IV CKD suggests induction of antioxidant defense mechanisms. Antioxidant defense systems might not be exhausted in CKD in cats.

Partial replacement of dietary buffalo meat on the bone with chicken carcass improves serum antioxidant profile of zoo‐housed Indian leopards (Panthera pardus fusca)

“…Very few studies report values of these parameters in felids. Serum concentrations of TAC ranged from 1.29 to 2.21 mmol/L (Krofič et al, ; Kayar et al, ) in domestic cats and from 0.93 to 1.27 mmol/L in dogs (Nemec et al, ). Serum concentration of SOD ranged from 56 to 80 U/ml in cats (Webb, Lehman, & McCord, ).…”

Urinary F2‐Isoprostanes in Cats with International Renal Interest Society Stage 1–4 Chronic Kidney Disease

“…For example, humans with advanced CKD show lower plasma activities of glutathione peroxidase (GPx), lower concentrations of its cofactor selenium, and lower reduced‐to‐oxidized glutathione (GSH:GSSG) ratios 6, 8, 35, 36. In contrast, cats with stage 4 CKD show a modest but significant increase in plasma GPx activities, with no decreases in serum selenium concentrations, and higher GSH:GSSG ratios 26, 37. In addition, humans with CKD often die of cardiovascular complications (related to systemic inflammation and oxidative stress), rather than of direct metabolic complications of uremia,38, 39 but this has not been observed in cats.…”

Acute phase proteins and biomarkers of oxidative status in feline spontaneous malignant mammary tumours

“…Serum PON1 concentrations were determined by spectrophotometry, using p‐nitrophenylacetate as substrate through a method previously validated for cats . Serum GPox concentrations were determined by a commercial kit (Ransel, Randox Laboratories Limited, Crumlin, UK) previously validated for use in cats . Total serum thiol concentrations were determined by a method that uses aromatic disulfides as reagents, previously validated for use in cats .…”

“…The CUPRAC was determined by a method that uses bathocuproinedisulfonic acid disodium salt as chelating agent, previously validated for use in feline serum . The TEAC was determined by two different methodologies, namely TEAC using an acidic medium (TEAC1) and TEAC using the horse radish peroxidase (TEAC2), both methods previously validated for cats …”