title: Effects of chronic, urea-induced osmotic diuresis on kidney weight and function in rats.
abstract: To study the effects of chronic osmotic diuresis which were not associated with hyperglycaemia on the rat kidney, osmotic diuresis was induced by i.v. infusion of urea. A 5 mol/l urea solution was continuously infused at a rate of 100 ml.kg-1 x day-1 on the basis of body weight on day 0. Duration of infusion was 2, 6, 10 or 14 days. Control rats received continuously infused Ringer's solution. Urea-treated groups developed osmotic diuresis (urine flow = about 0.04 ml.min-1 x 100 g body weight-1) comparable to that in rats with experimental diabetes mellitus induced by i.v. streptozotocin (55 mg/kg), however urea-induced osmotic diuresis was not associated with blood glucose level increases. Compared with their controls, rats receiving urea for 2-14 days had markedly increased kidney weight. Rats receiving urea for 10 days showed greatest kidney weight increase, 0.565 +/- 0.044 g/100 g body weight (mean +/- SD), representing a 53% increase compared with the control (0.369 +/- 0.034 g/100 g body weight). Kidney weight was associated with increases in kidney protein content. In contrast, none of control kidney weight values differed significantly from day 0 values (= normal rats; 0.387 +/- 0.028 g/100 g body weight). Creatinine clearance values in urea-treated groups were also higher than those in controls. The maximum value, 0.65 +/- 0.17.ml-min-1 x 100 g body weight-1, was recorded in the 14-day group and was significantly higher than the corresponding control value (0.34 +/- 0.07 ml.min-1 x 100 g body weight-1) (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Third Department of Internal Medicine, Okayama University Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ogino
authors.forename: S
authors.initials: S
authors.lastname: Okada
authors.forename: Z
authors.initials: Z
authors.lastname: Ota
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001806:Blood Urea Nitrogen; D001835:Body Weight; D003404:Creatinine / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000503:physiopathology; D004231:Diuresis / Q000187:drug effects / Q000502:physiology*; D004234:Diuretics, Osmotic; D005919:Glomerular Filtration Rate; D006984:Hypertrophy / Q000503:physiopathology; D007668:Kidney / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014508:Urea
chemical_list: D001786:Blood Glucose; D004234:Diuretics, Osmotic; D014508:Urea; D003404:Creatinine