Related Experiment Videos
Inactivation of porcine calcitonin by rat kidney microsome
Abstract:
Biological activity of porcine calcitonin was most actively inactivated by the rat kidney homogenate than by other tissue homogenates. Among the various subcellular fractions of the rat kidney homogenate examined, microsome fraction was most active in the in vitro inactivation of porcine calcitonin. Inactivation of porcine calcitonin by the rat kidney microsome was dependent on pH and temperature. Inactivating activity of the rat kidney microsome was inhibited by 1 X 10(-3) M monoiodoacetate and 1 X10(-5) M p-chloromercuribenzoate. These results suggest that porcine calcitonin is probably inactivated by a SH-enzyme in the rat kidney microsomes. However, the participation of other enzymes cannot be ruled out, since the inactivating activity of the rat kidney microsome fraction is also inhibited by 1 X 10(-4) M diisopropylfuorophosphate.
Insights
Rat kidney microsomes inactivate porcine calcitonin, likely via a sulfhydryl (SH) enzyme. This inactivation is influenced by pH, temperature, and specific inhibitors, suggesting a complex enzymatic process.
Area of Science:
- Biochemistry
- Pharmacology
Background:
- Calcitonin is a hormone with significant biological activity.
- Understanding its degradation is crucial for pharmacological applications.
Purpose of the Study:
- To investigate the inactivation of porcine calcitonin by rat kidney tissue.
- To identify the specific cellular components and enzymatic mechanisms involved in this inactivation.
Main Methods:
- Assessing the inactivation of porcine calcitonin by various rat tissue homogenates.
- Analyzing subcellular fractions of rat kidney homogenate for inactivating activity.
- Investigating the effects of pH, temperature, and enzyme inhibitors (monoiodoacetate, p-chloromercuribenzoate, diisopropylfuorophosphate) on inactivation.
Main Results:
- Rat kidney homogenate exhibited the highest inactivation activity against porcine calcitonin compared to other tissues.
- The microsome fraction of rat kidney homogenate was most potent in inactivating porcine calcitonin in vitro.
- Inactivation was dependent on pH and temperature.
- Activity was inhibited by sulfhydryl-reactive agents (monoiodoacetate, p-chloromercuribenzoate) and diisopropylfuorophosphate.
Conclusions:
- Porcine calcitonin is likely inactivated by a sulfhydryl (SH) enzyme present in rat kidney microsomes.
- The involvement of other enzymes cannot be excluded due to inhibition by diisopropylfuorophosphate.