RESUMEN
Some differences regarding Vitamin D metabolism are described in dogs and cats in comparison with humans, which may be explained by an evolutionary drive among these species. Similarly, vitamin D is one of the most important regulators of mineral metabolism in dogs and cats, as well as in humans. Mineral metabolism is intrinsically related to bone metabolism, thus disturbances in vitamin D have been implicated in the development of chronic kidney disease mineral and bone disorders (CKD-MBD) in people, in addition to dogs and cats. Vitamin D deficiency may be associated with Renal Secondary Hyperparathyroidism (RSHPT), which is the most common mineral disorder in later stages of CKD in dogs and cats. Herein, we review the peculiarities of vitamin D metabolism in these species in comparison with humans, and the role of vitamin D disturbances in the development of CKD-MBD among dogs, cats, and people. Comparative studies may offer some evidence to help further research about vitamin D metabolism and bone disorders in CKD.
RESUMEN
Due to the presence of receptors in the cells of numerous body tissues, vitamin D is associated with several physiological functions that go beyond calcium and phosphorus homoeostasis and control of bone metabolism in the body. In humans, several studies have associated lower vitamin D concentrations with numerous diseases, such as cancer, heart disease, autoimmune diseases and infectious diseases, and also with an increase in the total mortality rate of the population. Recently, this nutrient started to gain importance in veterinary medicine, and several articles have shown a correlation between low vitamin D status and diseases unrelated to bone metabolism. The present review aims to highlight the recent publications that investigated this relationship, bringing the evidence that exists so far in dogs and cats.
Asunto(s)
Enfermedades de los Gatos/metabolismo , Enfermedades de los Perros/metabolismo , Vitamina D/metabolismo , Animales , Huesos/metabolismo , Gatos , Perros , Deficiencia de Vitamina D/veterinariaRESUMEN
Hyperadrenocorticism is one of the most common endocrine disorders in dogs. Regarding to the kidneys, chronic hypercortisolemia can cause damage to the glomerulus, and evolve into chronic kidney disease. This study evaluated nine normotensive dogs with pituitary dependent hyperadrenocorticism, before and after therapy with trilostane, during the follow-up period of six months, in order to investigate the development of pathological proteinuria by quantitative (urinary protein-to-creatinine ratio) and qualitative (urinary protein electrophoresis) methods, and also to monitor its intensity over the course of the disease and therapy. The main renal lesion detected in dogs with hyperadrenocorticism was in the tubular segment, evidenced by the prevalence of urinary protein bands of lower molecular weight, indicating the lack absorption of these proteins in the proximal segment of the nephron. Low molecular weight proteins persisted throughout the follow-up. Regarding the future of routine veterinary medical clinic in the care of patients with hyperadrenocorticism, the assessments of proteinuria determinations by the urinary protein-to-creatinin ratio and urinary protein electrophoresis, according to the results obtained in this study, can add more information about the renal damage in these animals, and contribute to the prognosis.(AU)
Hiperadrenocorticismo (HAC) é uma das doenças endócrinas mais comuns em cães. A hipercortisolemia crônica pode causar danos glomerulares, pelo aumento da taxa de filtração glomerular, podendo levar ao desenvolvimento de doença renal crônica. Este estudo avaliou nove cães normotensos com hiperadrenocorticismo hipófise-dependente, antes e após a terapia com trilostano, durante o período de acompanhamento de seis meses, a fim de investigar o desenvolvimento de proteinúria patológica por métodos quantitativo (relação proteína e creatinina urinária) e qualitativos (eletroforese de proteínas urinárias) e também para monitorar a sua intensidade ao longo do curso da doença e terapia. A principal lesão renal detectada em cães com HAC foi no segmento tubular, evidenciada pela prevalência de bandas de proteínas urinárias de peso molecular mais baixo, indicando a falta de absorção destas proteínas no segmento proximal do néfron. A proteinúria de baixo peso molecular persistiu durante todo o acompanhamento. Em relação ao futuro da rotina clínica médica veterinária no tratamento de cães com hiperadrenocorticismo, as avaliações de proteinúria pela relação proteína e creatinina urinária e eletroforese de proteínas urinárias, de acordo com os resultados obtidos neste estudo, podem adicionar mais informações sobre a lesão renal nestes animais e contribuir para o prognóstico.(AU)
Asunto(s)
Animales , Perros , Proteinuria/veterinaria , Hidrocortisona/antagonistas & inhibidores , Hiperfunción de las Glándulas Suprarrenales/veterinaria , Electroforesis/veterinariaRESUMEN
BACKGROUND: Anemia and systemic oxidative stress may occur in dogs with chronic kidney disease (CKD). Only scarce information regarding the intraerythrocytic redox status under these conditions is available at this time. OBJECTIVE: The aim of this study was to evaluate the indicators of oxidative stress and intraerythrocytic antioxidant defense in dogs with anemia of CKD. METHODS: Thirty dogs with CKD in stages 3 or 4 with nonregenerative anemia (HCT ≤ 37%) were compared to 20 healthy dogs. Complete blood count, reticulocyte %, blood smear evaluation, intraerythrocytic concentrations of total (GSHt), reduced (GSH), and oxidized glutathione (GSSH), and activities of glutathione peroxidase, glutathione reductase and superoxide dismutase (SOD), as well as plasma concentrations of thiobarbituric acid-reactive substances (TBAR) were determined. RESULTS: Anemia of CKD dogs was nonregenerative (reticulocytes ≤ 0.2% with scarce anisocytosis and poikilocytosis). Intraerythrocytic GSSH and SOD, and plasma TBAR were higher in dogs with CKD. There was a positive correlation between the creatinine concentration and TBAR, and negative correlations between creatinine concentration and HCT, as well as between HCT and TBAR. In CKD dogs with a higher degree of anemia, SOD levels were higher and GSSH concentrations were lower. Despite the evidence of increased systemic oxidative stress, the compensatory response of SOD and the sustained intraerythrocytic concentrations of GSSH in CKD dogs with anemia indicated that the erythrocytes maintained the antioxidant defense. CONCLUSIONS: There was no strong evidence that oxidative stress was associated with higher degrees of anemia in dogs with CKD.
Asunto(s)
Anemia/veterinaria , Insuficiencia Renal Crónica/veterinaria , Anemia/fisiopatología , Animales , Antioxidantes/análisis , Perros , Eritrocitos/metabolismo , Femenino , Glutatión Peroxidasa/sangre , Glutatión Reductasa/sangre , Masculino , Estrés Oxidativo , Insuficiencia Renal Crónica/fisiopatología , Superóxido Dismutasa/sangre , Sustancias Reactivas al Ácido Tiobarbitúrico/análisisRESUMEN
O hiperadrenocorticismo é uma das endocrinopatias mais comuns em cães, sendo caracterizado pela exposição excessiva de glicocorticóides secretados pelas adrenais. A hipercortisolemia crônica pode promover várias complicações, incluindo hipertensão sistêmica e glomerulonefrite. A glomerulonefrite pode desencadear variáveis graus de proteinúria e uma tendência de evolução para doença renal crônica. A perda de proteínas na urina, principalmente da albumina, é uma característica das doenças glomerulares e a determinação de variáveis laboratoriais, como a razão proteína:creatinina urinária (RPC), albuminúria (teste de ELISA) e eletroforese das proteínas urinárias, são recomendadas para a elucidação do diagnóstico. Assim, o objetivo do estudo é avaliar a relação entre proteinúria e hipertensão arterial sistêmica em cães com hiperadrenocorticismo e verificar, pela avaliação da albuminúria e do peso molecular das proteínas urinárias, o segmento do néfron que foi comprometido ou lesado. Foram avaliados 30 cães com diagnóstico de hiperadrenocorticismo, subdivididos em 13 cães com hipertensão arterial sistêmica (grupo I) e 17 cães normotensos (grupo II). Foram determinados a RPC; a albuminúria pela avaliação da albumina normalizada e razão albumina:creatinina urinária (RAC) e a eletroforese de proteínas pela técnica em gel de poliacrilamida, contendo dodecil sulfato de sódio (SDS-PAGE). Os resultados foram comparados com os dados obtidos de 30 cães clinicamente saudáveis. Foi constatado que não houve influência da hipertensão arterial sistêmica nos cães com hiperadrenocorticismo em relação à quantificação da albuminúria, determinada pelo método ELISA, e nem na qualidade e quantidade das bandas de proteínas de baixo (<60 kDa) e de alto peso molecular (>60 kDa). No entanto foi determinado que cães com hiperadrenocorticismo podem desenvolver lesões glomerulares e tubulares, caracterizadas pela presença de albuminúria e de proteínas de alto e de baixo pesos moleculares, independentemente da presença de hipertensão arterial sistêmica. Conclui-se que a avaliação quantitativa (RPC e RAC) e qualitativa (SDS-PAGE) das proteínas urinárias traz informações adicionais que indicam os possíveis segmentos comprometidos dos néfrons que causaram as perdas de proteínas na urina.
Hyperadrenocorticism is one of the commonest endocrinopathies in dogs, and it is characterized by the excessive exposure of glucocorticoids excreted by adrenals. Chronic hypercortisolemia may promote several complications, including systemic hypertension and glomerulonephritis. Glomerulonephritis may initiate several variable degrees of proteinuria and leading to the development of chronic kidney disease. The loss of proteins through urine, mainly predominant albumin, is a characteristic of glomerular diseases and the determination of laboratorial variables, such as the urinary protein-to- creatinine ratio (UPC), urinary albumin-to-creatinine ratio (UAC; ELISA test) and electrophoresis of urinary proteins are recommended to elucidate the diagnosis. Therefore, the goal of this study is to evaluate the relationship between proteinuria and systemic arterial hypertension in dogs with hyperadrenocorticism and to determine through evaluation of albuminuria and molecular weight of urinary proteins, the segment of the nephron that could be damaged. Thirty dogs with hyperadrenocorticism were evaluated and subdivided into groups; 13 dogs with systemic arterial hypertension (group I) and 17 normotensive (group II). The UPC was determined, as well as UAC and the urine protein electrophoresis by polyacrylamide gel technique, containing dodecyl sodium sulphate (SDS-PAGE). The results were compared with data obtained from 30 clinically healthy dogs. No association between systemic arterial hypertension and albuminuria was detected in dogs with hyperadrenocorticism as well as no alterations of proteins patterns or molecular weights bands of low (<60 kDa) or high molecular weight (> 60 kDa) was found. However, dogs with hyperadrenocorticism may develop glomerular and tubular injuries that were characterized by the presence of albuminuria and proteins of low and high molecular weights, independently of systemic arterial hypertension. In conclusion, the quantitative (UPC and UAC) and qualitative (SDS-PAGE) evaluation of urinary proteins could add information to indicate the possible segments of the nephrons that caused the loss of those proteins.
Asunto(s)
Animales , Perros , Albuminuria/veterinaria , Glomerulonefritis/veterinaria , Hiperfunción de las Glándulas Suprarrenales/veterinaria , Hipertensión/veterinaria , Electroforesis en Gel de Poliacrilamida/veterinaria , Peso MolecularRESUMEN
Chronic kidney disease (CKD) is frequently observed in cats and it is characterized as a multisystemic illness, caused by several underlying metabolic changes, and secondary renal hyperparathyroidism (SRHPT) is relatively common; usually it is associated with the progression of renal disease and poor prognosis. This study aimed at determining the frequency of SRHPT, and discussing possible mechanisms that could contribute to the development of SRHPT in cats at different stages of CKD through the evaluation of calcium and phosphorus metabolism, as well as acid-base status. Forty owned cats with CKD were included and divided into three groups, according to the stages of the disease, classified according to the International Renal Interest Society (IRIS) as Stage II (n=12), Stage III (n=22) and Stage IV (n=6). Control group was composed of 21 clinically healthy cats. Increased serum intact parathyroid hormone (iPTH) concentrations were observed in most CKD cats in all stages, and mainly in Stage IV, which hyperphosphatemia and ionized hypocalcemia were detected and associated to the cause for the development of SRHPT. In Stages II and III, however, ionized hypercalcemia was noticed suggesting that the development of SRHPT might be associated with other factors, and metabolic acidosis could be involved to the increase of serum ionized calcium. Therefore, causes for the development of SRHPT seem to be multifactorial and they must be further investigated, mainly in the early stages of CKD in cats, as hyperphosphatemia and ionized hypocalcemia could not be the only factors involved.
A doença renal crônica (DRC) em gatos é frequentemente observada e caracteriza-se como alteração multissistêmica, causada por alterações metabólicas, e o hiperparatireoidismo secundário renal (HPTSR) seria o mais comum e usualmente está associada com progressão da doença renal e mau prognóstico. Esse estudo teve como objetivo determinar a frequência do HPTSR, e discutir os possíveis mecanismos que podem contribuir para o desenvolvimento de SRHPT em gatos em diferentes estágios de DRC, pela avaliação do metabolismo do cálcio e fósforo, bem como do equilíbrio ácido-base. Quarenta gatos com DRC foram divididos em três subgrupos, de acordo com a classificação proposta pela International Renal Interest Society (IRIS), Estágio II (n=12), Estágio III (n=22) e Estágio IV (n=6). O grupo-controle foi composto por 21 gatos clinicamente saudáveis. O aumento das concentrações séricas de paratormônio intacto (PTHi) foi observado na maioria dos casos, mas principalmente no Estágio IV, no qual a hiperfosfatemia e a hipocalcemia ionizada parecem estar associadas ao desenvolvimento do HPTSR. No entanto, nos Estágios II e III, observou-se hipercalcemia ionizada, sugerindo que, nestes estágios, o desenvolvimento do HPTSR possa estar associado a outros fatores, e a acidose metabólica pode estar envolvida com o desenvolvimento de hipercalcemia ionizada. Assim, outros fatores, além da hiperfosfatemia e da hipocalcemia ionizada, possam estar envolvidos com o desenvolvimento do HPTSR, principalmente nos estágios iniciais da DRC. Futuros estudos são necessários para uma melhor compreensão da fisiopatologia do HPTSR em gatos.
Asunto(s)
Animales , Gatos , Cetosis/veterinaria , Fallo Renal Crónico/veterinaria , Gatos/metabolismo , Hiperfosfatemia/veterinaria , Hiperparatiroidismo Secundario/veterinaria , Enfermedades Metabólicas/veterinaria , Hormona ParatiroideaRESUMEN
BACKGROUND: Microalbuminuria and hypertension have long been associated with a guarded prognosis in human patients with a variety of diseases. In veterinary medicine, tests for microalbuminuria have been used for detecting early kidney damage, but there is little information regarding its association with high blood pressure in dogs with chronic kidney disease (CKD). OBJECTIVE: The objective of this study was to evaluate albuminuria and its association with arterial hypertension in dogs with CKD. METHODS: Urinary albumin:creatinine (UAC) ratio, urinary protein:creatinine (UPC) ratio, and systolic blood pressure were determined in 39 clinically healthy dogs and 40 dogs with CKD. RESULTS: UAC in dogs with CKD (range, 0.002-7.99; median, 0.38) was statistically different from that of control dogs (range, 0.0005-0.01; median, 0.002). Microalbuminuria (UAC 0.03-0.3) and macroalbuminuria (UAC>0.3) were detected in 32.5% and 50% of dogs with CKD, respectively. Sixty percent (24/40) of dogs with CKD had systolic pressure > or =180 mmHg; in these dogs, UAC ratio (range, 0.006-7.99; median, 1.72) was significantly higher than in dogs with CKD and systolic pressure<180 mmHg (range, 0.002-4.83; median, 0.10). Of hypertensive dogs with CKD, those with UPC>1.0 usually had macroalbuminuria, those with UPC 0.5-1.0 usually had microalbuminuria, and those with UPC<0.5 usually lacked albuminuria. CONCLUSIONS: UAC ratio was higher in hypertensive than in normotensive dogs with CKD. Tests designed to detect microalbuminuria may be useful for hypertensive dogs with CKD and a UPC < or = 1.0 to detect the onset and magnitude of albuminuria. Once macroalbuminuria is overt, the UPC ratio itself can be used for the same purpose.
Asunto(s)
Albuminuria/veterinaria , Presión Sanguínea/fisiología , Enfermedades de los Perros/orina , Fallo Renal Crónico/veterinaria , Albuminuria/fisiopatología , Animales , Western Blotting/veterinaria , Creatinina/orina , Enfermedades de los Perros/fisiopatología , Perros , Electroforesis en Gel de Poliacrilamida/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Hipertensión/fisiopatología , Hipertensión/orina , Hipertensión/veterinaria , Fallo Renal Crónico/fisiopatología , Fallo Renal Crónico/orina , MasculinoRESUMEN
Microalbuminuria and hypertension have long been associated with a guarded prognosis in human patients with a variety of diseases. In veterinary medicine, tests for microalbuminuria have been used for detecting early kidney damage, but there is little information regarding its association with high blood pressure in dogs with chronic kidney disease (CKD).The objective of this study was to evaluate albuminuria and itsassociation with arterial hypertension in dogs with CKD.Urinary albumin:creatinine (UAC) ratio, urinary protein:creatinine(UPC) ratio, and systolic blood pressure were determined in 39 clinicallyhealthy dogs and 40 dogs with CKD.UAC in dogs with CKD (range, 0.0027.99; median, 0.38) was statistically different from that of control dogs (range, 0.00050.01; median, 0.002). Microalbuminuria (UAC 0.030.3) and macroalbuminuria(UAC40.3) were detected in 32.5% and 50% of dogs with CKD, respectively.Sixty percent (24/40) of dogs with CKD had systolic pressure Z180 mmHg; in these dogs, UAC ratio (range, 0.0067.99; median, 1.72) was significantly higher than in dogs with CKD and systolic pressure o180mmHg (range, 0.0024.83; median, 0.10). Of hypertensive dogswith CKD, those with UPC41.0 usually had macroalbuminuria, those with UPC 0.51.0 usually had microalbuminuria, and those with UPCo0.5 usually lacked albuminuria.UAC ratio was higher in hypertensive than in normotensive dogs with CKD. Tests designed to detect microalbuminuria may be useful for hypertensive dogs with CKD and a UPC 1.0 to detect the onset and magnitude of albuminuria. Once macroalbuminuria is overt, the UPC ratio itself can be used for the same purpose.
Asunto(s)
Animales , Perros , Albuminuria , Perros/lesiones , Hipertensión RenalRESUMEN
BACKGROUND: Chronic renal failure (CRF) is a common disease in dogs, and many metabolic disorders can be observed, including metabolic acidosis and calcium and phosphorus disturbances. Acidosis may change the ionized calcium (i-Ca) fraction, usually increasing its concentration. OBJECTIVE: In this study we evaluated the influence of acidosis on the serum concentration of i-Ca in dogs with CRF and metabolic acidosis. METHODS: Dogs were studied in 2 groups: group I (control group = 40 clinically normal dogs) and group II (25 dogs with CRF and metabolic acidosis). Serum i-Ca was measured by an ion-selective electrode method; other biochemical analytes were measured using routine methods. RESULTS: The i-Ca concentration was significantly lower in dogs in group II than in group I; 56% of the dogs in group II were hypocalcemic. Hypocalcemia was observed in only 8% of dogs in group II when based on total calcium (t-Ca) concentration. No correlation between pH and i-Ca concentration was observed. A slight but significant correlation was detected between i-Ca and serum phosphorus concentration (r = -.284; P = .022), as well as between serum t-Ca and i-Ca concentration (r = .497; P < .0001). CONCLUSION: The i-Ca concentration in dogs with CRF and metabolic acidosis varied widely from that of t-Ca, showing the importance of determining the biologically active form of calcium. Metabolic acidosis did not influence the increase in i-Ca concentration, so other factors besides acidosis in CRF might alter the i-Ca fraction, such as hyperphosphatemia and other compounds that may form complexes with calcium.
Asunto(s)
Acidosis Láctica/veterinaria , Calcio/sangre , Enfermedades de los Perros/sangre , Fallo Renal Crónico/veterinaria , Acidosis Láctica/sangre , Envejecimiento , Animales , Perros , Hipercalcemia/veterinaria , Hipocalcemia/veterinaria , Fallo Renal Crónico/sangreRESUMEN
The aim of this study was to evaluate the accuracy of serum beta-hydroxybutyrate (beta-OHB) measurements for the diagnosis of diabetic ketoacidosis (DKA) in dogs. One hundred sixteen diabetic dogs were prospectively enrolled in the study: 18 insulin-treated (IT) diabetic dogs that had a positive urine ketone test and 88 untreated, newly diagnosed diabetic dogs. Venous blood gas tensions and pH, serum glucose and urea nitrogen (SUN), and electrolyte (Na+, Cl-, and K+) and urine acetoacetate (AA) concentrations were measured concurrently with serum beta-OHB concentrations. On the basis of laboratory findings, the patients were assigned to I of 3 groups: diabetic ketoacidosis (n = 43); diabetic ketosis (DK, n = 41); and nonketotic diabetes (NDK, n = 31). Serum beta-OHB concentrations differed significantly (P < .001) among the study groups. Although marked differences in beta-OHB concentrations were found, a considerable overlap exists between the distributions of dogs with DK and those with DKA. The overall accuracy of beta-OHB determination as a diagnostic test for DKA, determined by the area under the receiver operating characteristic (ROC) curve, was 0.92. In the 1.9- to 4.8-mmol/L range, serum beta-OHB determination sensitivity varied from 100 to 35.7%, whereas specificity varied from 39 to 100%. The cutoff value of 3.8 mmol/L showed the best equilibrium between specificity (95%), sensitivity (72%), and likelihood ratio (14.8). We concluded that the quantitative measurement of serum beta-OHB may be a potential tool for diagnosing and monitoring ketosis and ketoacidosis in diabetic dogs.
Asunto(s)
Ácido 3-Hidroxibutírico/sangre , Cetoacidosis Diabética/veterinaria , Enfermedades de los Perros/diagnóstico , Acetoacetatos/orina , Animales , Glucemia , Nitrógeno de la Urea Sanguínea , Cetoacidosis Diabética/sangre , Cetoacidosis Diabética/diagnóstico , Enfermedades de los Perros/sangre , Perros , Electrólitos/sangre , Femenino , Masculino , Valor Predictivo de las Pruebas , Estudios Prospectivos , Curva ROC , Sensibilidad y EspecificidadRESUMEN
A fragilidade osmotica eritrocitaria foi estudada em desenove caes infectados naturalmente pela Leptospira interrogans serovar icterohaemorrhagiae/copenhagi. Observou-se uma reducao da fragilidade osmotica eritrocitaria, sem a presenca de anemia, possivelmente relacionada aos disturbios hepato-renais que ocorrem nesta patologia.