2113 A NOVEL TUBULAR SECRETION ASSAY ALLOWS A 24-HOUR URINE COLLECTION IN INVERTEBRATE MODELS OF URINARY STONE DISEASE (2012)

You have accessJournal of UrologyStone Disease: Evaluation & Medical Management I1 Apr 20122113 A NOVEL TUBULAR SECRETION ASSAY ALLOWS A 24-HOUR URINE COLLECTION IN INVERTEBRATE MODELS OF URINARY STONE DISEASE Thomas Chi, Man Su Kim, Lawrence Flechner, Joe Miller, Arnold Kahn, Pankaj Kapahi, and Marshall Stoller Thomas ChiThomas Chi San Francisco, CA , Man Su KimMan Su Kim Novato, CA , Lawrence FlechnerLawrence Flechner San Francisco, CA , Joe MillerJoe Miller San Francisco, CA , Arnold KahnArnold Kahn San Francisco, CA , Pankaj KapahiPankaj Kapahi Novato, CA , and Marshall StollerMarshall Stoller San Francisco, CA View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.2282AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES In clinical practice, the 24-hour urine is one of the most frequently used tools for risk stratification, metabolic evaluation, and therapeutic guidance for nephrolithiasis treatment. This is a test that has been replicated in vertebrate models with relative ease. In a Drosophila model for nephrolithiasis, the fruit fly contains Malpighian tubules, which are the functional equivalent of the human renal tubule. This is the location for ion absorption and secretion in Drosophila, just as in humans. We herein describe a technique to simulate a 24-hour urine collection in an invertebrate model. METHODS With careful microdissection, Drosophila Malpighian tubules were isolated and wrapped around a surgical pin in an ex vivo fashion. By leaving one end of the tubule in a droplet of dyed Schneiders medium suspended in oil, tubule function was preserved and the secreted fluid from the proximal end of the tubule could be collected into a droplet at the distal ureteral end as seen in Figure 1. This permitted collection of Malpighian tubular fluid in a fashion similar to that of a human 24-hour urine collection. Download PPT RESULTS Individual Malpighian tubules were monitored performing secretory function utilizing time lapsed photography for at least 12 hours in Schneider's medium. An aggregate of 8 ureteral droplets collected after 12 hours of secretion yielded 0.5 microliters of tubular fluid, a volume adequate for micro-mass spectrometric measurement for elemental analysis. CONCLUSIONS Tubular fluid can be collected in Drosophila melanogaster in an analogous fashion to human-24 hour urine collections. This will permit a better understanding of tubular secretion products within this invertebrate model, potentially leading to insight into early events of stone formation. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e853 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.Metrics Author Information Thomas Chi San Francisco, CA More articles by this author Man Su Kim Novato, CA More articles by this author Lawrence Flechner San Francisco, CA More articles by this author Joe Miller San Francisco, CA More articles by this author Arnold Kahn San Francisco, CA More articles by this author Pankaj Kapahi Novato, CA More articles by this author Marshall Stoller San Francisco, CA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...