Identification of cells exfoliated from the rat kidney in experimental nephrotoxicity

Identification of renal tubular epithelial cells in urine with immunofluorescence

Rabbits were immunized with human kidney homogenate. The rabbit sera, after absorption with human liver homogenate, showed antibody activity against human kidney, renal pelvis and urinary bladder. The sera were then absorbed with human renal pelvis and urinary bladder mucosa and subsequently showed no antibody activity against urinary bladder or renal pelvis. Immunofluorescence examinations showed fluorescing cells in kidney tubules, but not elsewhere. The finally absorbed antihuman kidney sera were used for indirect immunofluorescence examination of urinary sediments from patients with renal disease. Phase contrast microscopy was used simultaneously. Fluorescence was found in cells which in phase contrast microscopy were judged to be renal tubular cells. Fluorescing cells were often found in casts, but free cells were also seen. Immunofluorescence may thus provide a means of identifying renal tubular cells in urine.

Assessment of renal function and damage in animal species. A review of the current approach of the academic, governmental and industrial institutions represented by the Animal Clinical Chemistry Association

There are a wide variety of laboratory tests available to assess damage to and functional impairment of the kidneys, although the effectiveness of these tests varies greatly depending upon the site specificity of the damage and to a lesser extent upon the animal species involved. Several traditional tests of renal dysfunction and damage, including plasma creatinine and urea, and urinalysis (dipstick and/or quantitative protein), can be used in the first instance to detect nephrotoxicity. A second tier of specific, targetted indicators (concentration test, urinary enzymes, clearance of analytes, specific proteins, etc.) may then be applied to identify further the site of the lesion and the functional status of the kidneys. The glomerular filtration rate (GFR) may be estimated from the clearance of exogenous and endogenous substances. The difficulty in obtaining accurately timed urine samples limits the value of these tests in small animals, although methods that do not involve urine collection are available. The kidney is the origin of several enzymes found in urine that can be used to monitor the toxic effects of chemicals and therapeutic substances. Selective measurement of enzyme activities in urine can be used to detect the site of the renal lesion after traditional tests have established the presence of renal injury. Separation of proteins in urine by electrophoretic techniques may also be used to discriminate damage to different parts of the nephron. Renal cell excretion in urine is a sensitive but unreliable indicator of acute damage to the proximal tubule. The rate of cell excretion is not a good predictor of the severity of tubular injury.(ABSTRACT TRUNCATED AT 250 WORDS)