Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The localization of various peptidases in the renal section of the rat was investigated histochemically, and their activities were determined fluorometrically in renal homogenate. The membrane-bound peptidases aminopeptidase A (APA), aminopeptidase M (APM), gamma-glutamyl-transferase (gamma-GT), dipeptidylpeptidase IV (DAP IV), and the lysosomal dipeptidyl peptidases I (DAP I) and II (DAP II) were investigated in male and female (estrus) rats both before and 30 days after castration. In addition, protein excretion and APA, APM, DAP I and DAP IV activities were measured in the urine of these animals. Histochemically, the membrane-bound peptidases are demonstrable mainly in the brush borders of the proximal tubules. In addition, APA and DAP IV are found in the glomeruli, gamma-GT and DAP IV in the thin descending limbs of the loops of Henle, and gamma-GT in the basal labyrinth of the S2 and S3 segments. The lysosomal peptidases are most concentrated in the S1 and S2 segments of the proximal tubule, in the distal tubule, and in certain cells of the connecting tubule and collecting duct, where they are contained in lysosomes of varying size. Sex differences and castration effects are demonstrable both histochemically and biochemically for the investigated peptidases. Histochemically these effects are most pronounced in the S3 segments for the membrane-bound peptidases, and in the lysosomes of the proximal tubule for the lysosomal peptidases. Biochemical tests in controls show significantly higher lysosomal peptidase activities in the renal homogenate of females than of males. After castration the lysosomal peptidase activities in males increase, approaching those of females. This appears to have bearing on the sex-dependent proteinuria in rats, for lysosomal peptidases and proteinases are particularly important in the degradation of filtered proteins that are reabsorbed in the proximal tubule. In females high lysosomal peptidase activities correlate with a low proteinuria, while males demonstrate lower lysosomal peptidase activities and a significantly higher proteinuria than females. After castration, the lysosomal peptidase activities and proteinuria in males approach those in females. Renal peptidases are also excreted in the urine, again with sex differences, and so these excreted peptidases contribute to the proteinuria in rats.
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PMID:Peptidases in the kidney and urine of rats after castration. 704 50

The nephroprotective effects of pentoxifylline, a methylxantine, were studied in glycerol-induced acute renal failure. Glycerol treated rats exhibited collecting duct and medullary ascending limb dilation and casts, with focal tubular damage, confined mainly to the superficial cortex. In the interstitium focal mononuclear infiltration was observed. In some glomeruli there was swelling of mesangial spaces and mesangial cells. Pentoxifylline injected to glycerol pretreated rats exerted a protective effect. Only few groups of proximal tubules in the subcapsulary region of renal cortex showed necrosis and tubulorhexis. There were not leukocyte infiltrations or vascular congestion. Morphometric analysis showed increased surface area fraction of tubular lumen in rats treated with glycerol (p < 0.01) compared to those in controls. Intratubular cast formations in rats treated with glycerol alone were significantly higher than in rats given pentoxifylline in addition to glycerol. Kidney cortex ectopeptidases (APA, APN and DPP IV) were not significantly changed after glycerol administration. Serum creatinine and blood urea were markedly increased in glycerol treated rats, however, pentoxifylline reduced significantly their levels. This study in glycerol-induced acute renal failure showed a marked renal morphologic and functional protection by pentoxifylline.
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PMID:Nephroprotective effects of pentoxifylline in experimental myoglobinuric acute renal failure. 1250 69