Urinary concentration of aquaporin-2 water channel protein at different stages of chronic heart failure rats

AIM: To study urinary concentration of aquaporin-2 water channel protein(AQP2) at different stages of chronic heart failure(CHF) rats and its relation to hyponatremia. METHODS: Male Sprague-Dawley rats(200~250 g) underwent either a left coronary artery ligation (a model of CHF) or a sham-operation. At different stage after surgery, urinary AQP2 concentration was measured by Western blot. 24-hours urine volume, serum sodium and urine osmolality were measured at the same time. RESULTS: There were two peaks of urinary excretion of AQP2 in severe heart failure rats model: one was the third day after operation, the other was the 9th week. Serum sodium and urine osmolality were significantly different in CHF rats as compared with sham-operated rats. Seven weeks after surgery, urinary AQP2 concentration was increased significantly insevere CHF rats compared with the mild ones and the control ones(365%±103% vs 179%±81% and 99%±48%, P＜0.01).CONCLUSION: The variation of urinary AQP2 excretion at different stages after ligation showed that the expression of AQP2 gene was increased obviously in CHF rats, and its expression level was higher as the heart failure became more severe.This is the important reason of heart failure with hyponatremia.     

Acid-base and electrolyte abnormalities in dogs with gastrointestinal foreign bodies

Gastrointestinal foreign bodies occur commonly in dogs. The objective of the study was to describe the acid-base and electrolyte abnormalities identified in dogs with gastrointestinal foreign bodies and determine if these abnormalities are related to the site or type of foreign body present. Medical records of 138 dogs were reviewed, and information on signalment, initial venous electrolyte and acid-base values, surgical findings, relevant historical information, imaging modalities used, cost of hospital visit, intra- or postoperative complications, and survival was obtained. The site of the foreign body was recorded in 94.9% of cases and the most common site was the stomach (50%), followed by the jejunum (27.5%). The foreign bodies were linear in 36.2% of cases. The most common electrolyte and acid-base abnormalities regardless of the site or type of foreign body were hypochloremia (51.2%), metabolic alkalosis (45.2%), hypokalemia (25%), and hyponatremia (20.5%). No significant association was found between electrolyte or acid-base abnormalities and the site of foreign body. Linear, as opposed to discrete, foreign bodies were more likely to be associated with a low serum sodium concentration (odds ratio, 0.85; 95% confidence interval, 0.75-0.95). Hyperlactatemia (> 2.4 mmol/L) was seen in 40.5% of dogs. A wide variety of electrolyte and acid-base derangements are found in dogs with gastrointestinal foreign bodies. Hypochloremia and metabolic alkalosis are common in these dogs. Hypochloremic, hypokalemic metabolic alkalosis is seen with both proximal and distal gastrointestinal foreign bodies.     

Presumptive Iatrogenic Microcystin‐Associated Liver Failure and Encephalopathy in a Holsteiner Gelding

An 8‐year‐old Holsteiner gelding was presented for evaluation of anorexia, obtundation, icterus, and mild colic signs of 48 hours duration. History, physical examination, and initial diagnostics were suggestive of hepatic disease and encephalopathy. Microcystin toxicosis was suspected based on historical administration of a cyanobacteria supplement, associated serum biochemistry abnormalities, and characteristic histopathological changes. Microcystin contamination was confirmed in both supplement containers fed to the horse. Fulminant hepatic failure and encephalopathy progressed resulting in euthanasia. Necropsy findings were consistent with microcystin induced liver failure.     

Cerebral salt wasting syndrome

There is significant evidence to show that many neurosurgical patients with hyponatremia, who were previously diagnosed with syndrome of inappropriate antidiuretic hormone secretion (SIADH), actually have cerebral salt wasting syndrome (CSWS). The critical difference between SIADH and CSWS is that CSWS involves renal salt loss leading to hyponatremia and volume loss, whereas SIADH is a euvolemic or hypervolemic condition. The primary treatment for CSWS is water and salt replacement. The mechanisms underlying CSWS are not understood but may involve ANP or other natriuretic factors and direct neural influence on renal function.     

脑性盐耗综合征54例临床分析

目的探讨颅脑损伤、脑血管病及颅内占位性病变切除术后并发脑性盐耗综合征的原因、诊断及治疗方法,以提高颅脑疾病的综合治疗水平．方法回顾性分析54例颅脑损伤、脑血管病及颅内占位性病变切除术后并发脑性盐耗综合征患者的临床资料．结果全部病例均符合CSWS诊断金标准,患者于术后4—10d血清钠均低于130mmol／L,24h尿钠均大于80mmol／L,血浆渗透压小于270mmol／L．经治疗,48例患者恢复正常,2例患者入院后病情危重死亡,1例放弃治疗,死于低钠血症,1例死于术后出血性脑梗死,2例为长期植物生存状态．结论脑性盐耗综合征诊断标准是低血钠、高尿钠、低血容量,中重度颅脑外伤术后和鞍区、下丘脑病变患者手术后常并发此症,应该及时给予患者补钠、补液治疗,绝大多数预后良好．