Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of the lysosomal endopeptidase cathepsin B (cath B; CZB-Ala-Arg-Arg-MNA as substrate) and the lysosomal exopeptidase dipeptidylpeptidase II (DAP II; Lys-Ala-2NA as substrate) were fluorometrically determined in the renal homogenate of normal and experimental (castration followed by a 14-day treatment with estradiol and testosterone) rats of both sexes. In addition, methodological investigations of the renal homogenate were performed in order to differentiate cath B from other proteinases. These showed that cath-B activity was highest at around pH 6, was strongly inhibited by 4-hydroxymercuribenzoate and leupeptin, and was activated by dithiothreitol. Trypsin-like activities were not demonstrable under the used incubation conditions. The animal experiments showed that renal cath-B activities (1) were significantly higher in females than in males, (2) increased significantly in males and decreased significantly in females after castration (no significant difference between both sexes), (3) decreased in female and male castrates after treatment with testosterone and increased strongly after treatment with estradiol, and (4) showed an activity pattern similar to that of DAP II. The results are discussed in relation to the sex-dependent and sex-hormone-dependent proteinuria of rats. It is suggested that there is a correlation between protein catabolism in the kidney and proteinuria, i.e. high lysosomal proteinase activities correspond with low proteinuria.
 ...
PMID:Renal cathepsin-B activities in rats after castration and treatment with sex hormones. 374 98

The localization of aminopeptidase M (APM), dipeptidyl peptidase I (DAP I), II (DAP II) and IV (DAP IV) in the renal section was investigated histochemically, and their activities were determined fluorometrically in renal homogenate of normal, castrated and testosteron treated male rats.--After castration the activities of the lysosomal DAP II (pars convoluta of the proximal tubule), DAP I (distal and proximal tubule) and of the mainly membrane-bound DAP IV (glomeruli, brush border of the proximal tubule) increase in comparison to normal males, whereas the activities of the brush border-bound APM decrease. After testosteron treatment of castrated animals (0.1, 0.5 and 1.0 mg testosterone proprionate/100 g BW and day; 5-day treatment) the activities of DAP I, II and IV decrease again, so that after treatment with 0.1 mg testosterone proprionate, the activities of DAP I and II approach those in normal males.--The additionally determined urinary protein excretion shows that there is a significant decrease in proteinuria after castration, whereas testosterone treatment of castrated animals is accompanied by an increase of proteinuria.--Our results would suggest that the protein catabolism in the proximal tubule and the proteinuria are interrelated, and that testosterone influences (decreases) the protein catabolism in the proximal tubule. This means that high activities of lysosomal proteinases in the proximal tubule (castrates) are accompanied by a low proteinuria, and low activities of those proteinases (testosterone treated castrated or normal males) by a high proteinuria.
 ...
PMID:[Peptidases in the kidney of male rats following castration and testosterone substitution]. 614 13

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.
 ...
PMID:Peptidases in the kidney and urine of rats after castration. 704 50