Venn-Watson Stephanie, Smith Cynthia R, Johnson Shawn, Daniels Risa, Townsend Forrest
National Marine Mammal Foundation, San Diego, California 92106, USA.
Dis Aquat Organ. 2010 Mar 9;89(2):167-77. doi: 10.3354/dao02187.
Few cases of nephrolithiasis (renal calculi) have been reported in bottlenose dolphins Tursiops truncatus. A case-control study was conducted to compare ultrasonographic images and clinicopathologic serum and urine values among 14 dolphins with nephrolithiasis (mild cases: 1 to 19 nephroliths, n = 8; advanced cases: > or = 20 nephroliths, n = 6) to 6 controls over an 18 mo period. Archived nephroliths collected postmortem from 7 additional bottlenose dolphins were characterized using quantitative analysis. All advanced cases had bilateral nephroliths, and 67% had visible collecting ducts. During the study, 2 of the advanced cases developed hydronephrosis, and 1 of these cases had ureteral obstruction due to a nephrolith. Compared to controls, cases (mild and advanced) were significantly more likely to have anemia (hematocrit [HCT] < 38%), high blood urea nitrogen (>59 mg dl(-1)), high creatinine (>1.9 mg dl(-1)), and low estimated glomerular filtration rate (<150 ml min(-1) 2.78 m(-2)). Advanced-case urine samples were more likely to have erythrocytes, occult blood, and lower pH compared to mild cases and controls. Mean serum uric acid among all study groups was low (0.15 to 0.27 mg dl(-1)). Urinary uric acid concentrations were highest among mild cases (272 mg g(-1) creatinine), but advanced cases had levels lower than that of controls (40 and 127 mg g(-1) creatinine, respectively). All nephroliths were characterized as 100% ammonium acid urate. We conclude that nephrolithiasis is clinically relevant in dolphins and can decrease renal function and HCT. The presence of nephrolithiasis, presumably ammonium acid urate nephrolithiasis, in the face of low serum uric and relatively low urinary uric acid in advanced cases may indicate a metabolic syndrome similar to that reported in humans.
宽吻海豚患肾结石的病例报道较少。开展了一项病例对照研究，在18个月的时间里，比较了14只患有肾结石的海豚（轻度病例：1至19颗肾结石，n = 8；重度病例：≥20颗肾结石，n = 6）与6只对照海豚的超声图像以及临床病理血清和尿液值。对另外7只宽吻海豚死后收集的存档肾结石进行了定量分析。所有重度病例均为双侧肾结石，67%有可见的集合管。在研究期间，2例重度病例出现肾积水，其中1例因肾结石导致输尿管梗阻。与对照组相比，病例组（轻度和重度）更易出现贫血（血细胞比容[HCT]<38%）、高血尿素氮（>59 mg dl⁻¹）、高肌酐（>1.9 mg dl⁻¹）以及低估计肾小球滤过率（<150 ml min⁻¹ 2.78 m⁻²）。与轻度病例和对照组相比，重度病例的尿液样本更易出现红细胞、潜血以及更低的pH值。所有研究组的平均血清尿酸水平较低（0.15至0.27 mg dl⁻¹）。轻度病例的尿尿酸浓度最高（272 mg g⁻¹肌酐），但重度病例的水平低于对照组（分别为40和127 mg g⁻¹肌酐）。所有肾结石均被鉴定为100%尿酸铵。我们得出结论，肾结石在海豚中具有临床相关性，可降低肾功能和血细胞比容。在重度病例中，面对低血清尿酸和相对较低的尿尿酸，肾结石（推测为尿酸铵肾结石）的存在可能表明存在一种与人类报道相似的代谢综合征。
