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A comparison between naturally occurring macroamylasaemia and macroamylasaemia induced by hydroxyethyl-starch
Abstract:
Macroamylasaemia was produced in vitro by incubation of hydroxyethylstarch with serum, and in vivo by intravenous infusion of hydroxyethylstarch. Gel filtration on Sephadex G-100 revealed distinct differences in molecular size distribution between such hydroxyethylstarch-induced macroamylase and the usual form of naturally occurring macroamylase which was observed in a few patients from our hospital. Further studies demonstrated that the gel filtration elution pattern of amylase activity in serum containing hydroxyethylstarch-induced macroamylase is significantly altered with time in vitro and in vivo, probably because of an enzymatic degradation of the hydroxyethylstarch components of the macromolecular complexes. In a healthy volunteer the serum amylase activity was elevated to a maximum of 797 u/l and the renal clearance rate of amylase was diminished to a minimum of 0.3 ml/min after infusion of 500 ml of a 6% solution of hydroxyethylstarch, as compared to 300 u/l, and 0.95 ml/min, respectively, during the pre-infusion period.
Insights
Hydroxyethylstarch infusion can induce macroamylasemia by forming macromolecular complexes with amylase. These complexes alter amylase clearance and molecular size, differing from naturally occurring macroamylase.
Area of Science:
- Biochemistry
- Clinical Chemistry
Background:
- Macroamylasemia is a condition characterized by the presence of macroamylase in the blood.
- The etiology and characteristics of induced macroamylasemia are not fully understood.
Purpose of the Study:
- To investigate the in vitro and in vivo production of macroamylasemia using hydroxyethylstarch.
- To compare hydroxyethylstarch-induced macroamylase with naturally occurring macroamylase.
- To analyze the changes in molecular size and renal clearance of amylase in response to hydroxyethylstarch.
Main Methods:
- In vitro incubation of serum with hydroxyethylstarch.
- In vivo intravenous infusion of hydroxyethylstarch in a healthy volunteer.
- Gel filtration chromatography (Sephadex G-100) to assess molecular size distribution.
- Measurement of serum amylase activity and renal clearance rates.
Main Results:
- Hydroxyethylstarch induced macroamylasemia in vitro and in vivo.
- Distinct differences in molecular size were observed between hydroxyethylstarch-induced and naturally occurring macroamylase.
- Gel filtration elution patterns of amylase activity changed over time, suggesting enzymatic degradation of hydroxyethylstarch components.
- In a healthy volunteer, serum amylase activity increased significantly, and renal clearance decreased after hydroxyethylstarch infusion.
Conclusions:
- Hydroxyethylstarch can induce macroamylasemia through the formation of macromolecular complexes.
- Hydroxyethylstarch-induced macroamylase exhibits different molecular characteristics compared to naturally occurring macroamylase.
- The study highlights the impact of hydroxyethylstarch on amylase metabolism and renal clearance.