Phosphorus and phosphate metabolism in veterinary patients

Objective: To review phosphorus and phosphate metabolism and the importance of phosphate abnormalities in veterinary patients. Data sources: A review of recent human and veterinary medical literature. Human data synthesis: There is a significant amount of original research on human patients with phosphate abnormalities. Hypophosphatemia has been studied in patients with diabetic ketoacidosis (DKA), head trauma, refeeding syndrome, hypothermia and in ventilator patients that fail to wean. Hyperphosphatemia has been studied in patients with renal failure and malignancy. Phosphate levels have also been evaluated for prognostic value in sepsis and acute liver failure. Veterinary data synthesis: Although animal models were used in early experimental research, fewer studies have been published on the effects of phosphate abnormalities in veterinary patients. Hypophosphatemia has been studied in animals with DKA, with refeeding syndrome and with hyperparathyroidism. Hyperphosphatemia has been studied in animals with renal failure and with secondary hypoparathyroidism. Conclusion: Phosphorus and phosphate are important in many biological functions. This paper is a review of their role in normal metabolism and the clinical importance of phosphate imbalances for our emergency and critical care patients.     

Diagnostic potential of natriuretic peptides in the occult phase of golden retriever muscular dystrophy cardiomyopathy

The objective of the study was to determine whether the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP, respectively) could be reliable markers of cardiac alterations during occult cardiomyopathy in Golden Retriever Muscular Dystrophy (GRMD). Fifty Golden Retrievers without any clinical or radiographic sign of heart disease were included in this study (21 GRMD dogs and 29 controls). Controls and GRMD dogs were divided into 2 subgroups according to age (< and > or =12 months old, respectively). All dogs underwent echocardiography and determination of BNP and ANP plasma concentrations by radioimmunoassay. No ventricular dilatation or dysfunction was observed in either control or GRMD dogs. ANP plasma concentration did not differ significantly between controls and GRMD dogs (mean +/- SD = 72 +/- 49 versus 58 +/- 23 pg/mL, respectively, P = .21). This finding was confirmed in both subgroups of dogs (ie, those < and > or =12 months old). In contrast, BNP plasma concentrations were significantly higher in GRMD dogs than in controls (mean +/- SD = 117 +/- 92 versus 46 +/- 22 pg/mL, respectively, P < .05). In dogs > or =12 months old, sensitivity and specificity of BNP for identifying GRMD with a cutoff of 65 pg/mL were 78 and 86%, respectively. For the same cutoff value, sensitivity dropped to 42%, whereas specificity reached 100% in dogs <12 months old. In conclusion, BNP may be a useful biochemical marker of asymptomatic cardiomyopathy. However, this peptide does not allow very early detection because its optimal discriminatory power was observed in adult dogs (ie, > or =12 months of age).     

Clinical, echocardiographic, and neurohormonal effects of a sodium-restricted diet in dogs with heart failure

The use of low-sodium diets in dogs with heart failure is common practice, but randomized, double-blind studies have not been conducted to examine the benefits or problems with this approach. The purpose of this study was to determine the effects of a low-sodium diet on clinical, echocardiographic, and neurohormonal parameters in dogs with heart failure. Dogs with stable chronic heart failure were fed exclusively a low-sodium (LS) and a moderate-sodium (MS) diet for 4 weeks each in a randomized, double-blind, crossover design. At days 0, 28, and 56, echocardiography and thoracic radiography were performed, and blood was analyzed for electrolytes and neurohormones. Fourteen dogs completed the study (9 with chronic valvular disease and 5 with dilated cardiomyopathy). Electrolyte abnormalities were common during the study, and serum sodium and chloride concentrations decreased significantly on the LS diet. Neurohormones did not change significantly between diet groups. Maximum left atrial (P = .05) and standard left atrial (P = .09) size decreased on the LS diet. For dogs with chronic valvular disease, vertebral heart score (P = .05), left ventricular internal dimension in diastole (P = .006) and systole (P = .02), standard left atrial dimension (P = .03), maximum left atrial dimension (P = .02), end-diastolic volume index (P = .02), and end-systolic volume index (P = .04) decreased significantly on the LS diet compared to the MS diet. Although analysis of these data suggests some benefits of a low-sodium diet, future studies with improved study design are needed to further evaluate the advantages and disadvantages of sodium restriction in dogs with heart failure.     

Expression of FBXW7 in diabetic cardiomyopathy

AIM:To investigate the expression of F-box/WD repeat-containing protein 7 (FBXW7) in the myocardium of type 1 diabetic rats and to clarify its role in the development of diabetic cardiomyopathy. METHODS:All rats were randomly divided into non-diabetic (ND) group, 4-week diabetes mellitus (DM) model group, 8-week DM mo-del group and 12-week DM model group. The DM model was prepared by intraperitoneal injection of streptozotocin (60 mg/kg). The change of myocardial pathological structure was investigated by HE staining. The FBXW7 expression level in the myocardium was determined by Western blot and immunohistochemistry methods. RESULTS:DM induced cardiomyocyte degeneration and necrosis as shown by cardiac histological analysis. Both Western blot and immunohistochemistry results showed that the expression level of FBXW7 was significantly increased in 4-week, 8-week and 12-week DM groups compared with control group (P<0.01). However, The FBXW7 expression level in 12-week DM group was decreased compared with 4-week and 8-week DM groups. CONCLUSION:With the development of diabetes, the expression of FBXW7 in the myocardium of the rats with diabetic cardiomyopathy shows a tendency to increase first and then decrease, suggesting that it plays some roles in the development of diabetic cardiomyopathy.     

青钱柳提取物对家兔实验性糖尿病模型降血糖作用的研究

分别以每天8g/kg体重剂量的青钱柳水提物和醇提物灌饲糖尿病模型家兔,以血糖、体重、糖耐量为指标研究青钱柳提取物的降糖作用。结果表明,经5周试验,灌饲青钱柳提取物家兔的血糖浓度明显低于糖尿病模型对照组,其中青钱柳醇提取物的降糖效果更好(P<0.01)。青钱柳提取物还能减缓实验性糖尿病家兔体重下降,对试验性家兔的糖耐量具有显著的增强作用。     

扩张型心肌病患者红细胞免疫功能、超氧化物歧化酶及血浆过氧化脂质的检测及临床意义

目的：探讨扩张型心肌病(DCM)患者红细胞免疫功能与过氧化脂质的关系。方法：选取本院DCM患者共118例，按NYHA标准分组，心功能Ⅱ级组4l例、Ⅲ级组37例、Ⅳ级组40例；健康人对照组48例。两组同步检测红细胞C3b受体、血浆丙二醛(MDA)及红细胞超氧化物歧化酶(SOD)水平，其中，红细胞C3b受体检测采用红细胞酵母菌混合花环法，MDA采用硫代巴比妥酸(TBA)法测定，红细胞SOD测定采用邻苯三酚自氧化反应法，并作比较和相关分析。结果：DCM心功能Ⅳ级患者红细胞受体花环率(RBC—C3bRR)和红细胞免疫复合物花环率(RBC—ICR)较心功能Ⅲ级、Ⅱ级患者及对照组均明显降低，差异具显著意义(P＜0．0l，＜0．05)。相关分析表明．RBC—C3bRR与MDA呈高度负相关、与SOD呈中度正相关，相关系数分别为-0．83和 0．72。结论：DCM患者存在红细胞免疫功能下降及LPO增加，并随心功能的减弱而加重，这可能与脂质过氧化损伤有关。