Effect of the Phosphodiesterase-5 Inhibitor Zaprinast on Ischemia-Reperfusion Injury in Rats

The cardiac and renal protective effects of phosphodiesterase-5 (PDE-5) inhibitors against ischemia-reperfusion injury have recently been demonstrated in animal studies. We evaluated the effect of pretreatment with the PDE-5 inhibitor zaprinast on warm renal ischemia in a rat model

Updates on the use of ureteral stents: focus on the Resonance® stent

Manoj V Rao, Anthony J Polcari, Thomas MT TurkDepartment of Urology, Loyola University Medical Center, Maywood, IL, USAAbstract: The Resonance® metallic ureteral stent is one of the latest additions to the urologist’s armamentarium in managing ureteral obstruction. One advantage of this stent over traditional polymer-based stents is resistance to encrustation with stone material, which allows longer dwell times and less frequent exchange procedures. Although exchanging a metallic stent is slightly more complicated than exchanging a polymer stent, the fluoroscopic techniques required are familiar to most urologists. The Resonance stent is also more resistant to compression by external forces, potentially allowing greater applicability in patients with metastatic cancer. Furthermore, the use of this stent in patients with benign ureteral obstruction is shown to be associated with significant cost reduction. Clinical studies on the use of this stent are accumulating and the results are mixed, although Level 1 evidence is lacking. In this article we present a comprehensive review of the available literature on the Resonance metallic ureteral stent.Keywords: resonance, metallic, ureteral, stent, obstructio

Effect of the Phosphodiesterase-5 Inhibitor Zaprinast on Ischemia-Reperfusion Injury in Rats

PURPOSE: The cardiac and renal protective effects of phosphodiesterase-5 (PDE-5) inhibitors against ischemia-reperfusion injury have recently been demonstrated in animal studies. We evaluated the effect of pretreatment with the PDE-5 inhibitor zaprinast on warm renal ischemia in a rat model. METHODS: Female Sprague-Dawley rats underwent concomitant right nephrectomy and left renal hilar occlusion for 30 minutes. Twelve animals were equally divided into three groups: Group 1 received no pharmacologic pretreatment, group 2 was pretreated with zaprinast 10 mg/kg, and group 3 was pretreated with zaprinast 20 mg/kg. Zaprinast was dissolved in 25% dimethyl sulfoxide and given as a single intraperitoneal injection 30 minutes before surgery. Serum blood urea nitrogen (BUN) and creatinine levels, histopathology, and TUNEL staining for apoptosis were assessed 24 hours postoperatively. RESULTS: The mean creatinine level for groups 1, 2, and 3 was 0.73 mg/dL, 0.55 mg/dL, and 0.38 mg/dL, respectively. These values were not statistically different (P=0.099). The mean BUN levels of 35.8 mg/dL for group 1, 27.3 mg/dL for group 2, and 23.3 mg/dL for group 3 were also statistically similar (P=0.278). There were no objective differences in histopathologic evaluation or TUNEL staining between the groups. CONCLUSION: This study did not demonstrate a beneficial effect of zaprinast pretreatment on renal parameters after warm ischemic injury