Hepatic and lipoprotein lipases selectively assayed in postheparin plasma

Area of Science:

• Biochemistry
• Enzymology
• Clinical Chemistry

Background:

• Lipoprotein lipase (LPL) and hepatic lipase (HL) are key enzymes in lipid metabolism.
• Accurate measurement of LPL and HL activity is crucial for understanding lipid disorders.
• Existing assays may lack specificity or reliability for simultaneous LPL and HL determination.

Purpose of the Study:

• To develop and validate sensitive, reliable assays for the selective quantification of LPL and HL in postheparin plasma.
• To investigate potential sex differences in LPL and HL activity in healthy adults.

Main Methods:

• Developed a selective assay for HL by inhibiting LPL using high salt concentration (0.76 mol/L NaCl).
• Developed a selective assay for LPL by denaturing HL using sodium dodecyl sulfate.
• Validated the LPL assay against a method using an antiserum to inactivate HL.
• Quantified LPL and HL activity in plasma samples from 32 normal adults.

Main Results:

• Achieved selective measurement of LPL and HL activity.
• Demonstrated a clear sex difference in both enzyme activities.
• Men, on average, exhibited higher HL activity compared to women.
• Men, on average, exhibited lower LPL activity compared to women.

Conclusions:

• The developed assays provide sensitive and reliable methods for distinguishing LPL and HL activity.
• Significant sex-based differences in LPL and HL activity exist in the adult population.
• These findings contribute to a better understanding of lipase function in lipid metabolism and potential sex-specific variations.