Related Experiment Videos
Acid phosphatase activity in the mammalian nephron
The American Journal of Physiology
|August 1, 1984
Summary
Lysosomal acid phosphatase (AcPase) activity in rat and rabbit kidneys varied across nephron segments. Unexpectedly high AcPase levels were found in the distal nephron, suggesting extralysosomal activity or higher enzyme concentration.
Area of Science:
- Nephrology
- Cell Biology
- Biochemistry
Background:
- Lysosomal acid phosphatase (AcPase) is crucial for cellular function.
- Understanding AcPase distribution in the nephron is key to renal physiology.
Purpose of the Study:
- To quantify AcPase activity in distinct segments of rat and rabbit nephrons.
- To investigate the localization and potential isoenzymes of AcPase within the kidney.
Main Methods:
- Enzyme assays using 4-methylumbelliferyl phosphate as substrate.
- Measurement of AcPase activity in isolated nephron segments from rats and rabbits.
- Analysis of reaction product generation linearity with time and tubule length.
Main Results:
- Rat kidneys showed higher AcPase activity in glomeruli and proximal tubules than rabbit kidneys.
- AcPase activity was higher in juxtamedullary glomeruli compared to superficial ones in both species.
- Unexpectedly high AcPase activity was observed in the rabbit cortical collecting duct and in various segments of the male rat distal nephron.
Conclusions:
- The distal nephron exhibits significant AcPase activity, potentially indicating extralysosomal localization or higher per-volume enzyme concentration.
- Differences in K'm values in rabbit S1 segments and cortical collecting duct suggest the presence of distinct AcPase isoenzymes.
- Findings challenge traditional views on lysosomal enzyme distribution within the nephron.