title: Influence of hydration state on renal functions of dogs.
abstract: Clinically normal dogs were evaluated in states of dehydration, euhydration, and after fluid administration to determine effects of hydration state on renal clearance values. Endogenous creatinine, exogenous creatinine, and [14C]inulin clearances, were determined to measure glomerular filtration rate (GFR); in some experiments p-aminohippurate clearance was determined to measure renal plasma flow. Dehydration caused significant (P < 0.05) decrease in clearance values, compared with euhydration, and clearance values during euhydration were significantly (P < 0.05) less than values obtained after a single gavage with water (30 ml/kg of body weight). Sustained administration of 3 fluid regimens was evaluated for effects on clearance values (treatment A = 30 ml of lactated Ringer's solution/kg/h; treatment B = 30 ml of water/kg by gavage hourly; treatment C = 10 ml of glucose:lactated Ringer's solution/kg/h). All regimens of fluid therapy caused significant P < 0.05), progressive increases in GFR, but treatment C resulted in the most stable GFR values. Increases in clearance values were associated with positive fluid balance; the rate of fluid administration was greater than the rate of urine formation. Data from 285 GFR determinations on 85 dogs were evaluated retrospectively. For each determination, three 20-minute urine collections were made beginning 40 minutes after 30 ml of water/kg was given by gavage. Values between collections were significantly (P < 0.05) different, but varied by < 3%. Comparison of methods for measurement of GFR indicated that endogenous creatinine clearance and [14C]inulin clearance were highly correlated (R2 = 0.82), but mean clearance values were markedly different (mean +/- SEM, 28.70 +/- 0.01 and 37.07 +/- 1.29 ml/min, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens 30602.
authors.forename: H
authors.initials: H
authors.lastname: Tabaru
authors.forename: D R
authors.initials: DR
authors.lastname: Finco
authors.forename: S A
authors.initials: SA
authors.lastname: Brown
authors.forename: T
authors.initials: T
authors.lastname: Cooper
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000502:physiology*; D003404:Creatinine / Q000378:metabolism; D003681:Dehydration / Q000503:physiopathology / Q000662:veterinary; D004283:Dog Diseases / Q000503:physiopathology; D004285:Dogs / Q000502:physiology*; D005260:Female; D005440:Fluid Therapy / Q000662:veterinary; D005919:Glomerular Filtration Rate / Q000662:veterinary*; D007444:Inulin; D008297:Male; D014867:Water / Q000494:pharmacology
chemical_list: D014867:Water; D007444:Inulin; D003404:Creatinine