Pseudocholinesterase activity in human cerebrospinal fluid.

Area of Science:

• Biochemistry
• Neuroscience
• Clinical Chemistry

Background:

• Pseudocholinesterase (PCHE) is an enzyme primarily found in plasma, crucial for metabolizing certain drugs.
• Understanding PCHE activity in cerebrospinal fluid (CSF) is important for neurological conditions and drug responses.
• Dibucaine number (DN) is a measure of PCHE's sensitivity to inhibition, indicating enzyme variants.

Purpose of the Study:

• To quantify and compare Pseudocholinesterase (PCHE) activity and dibucaine numbers (DN) in human cerebrospinal fluid (CSF) and plasma.
• To investigate changes in CSF PCHE activity and DN in patients with intraventricular bleeding.

Main Methods:

• Kinetic assay method was employed to measure PCHE activity.
• Dibucaine number (DN) was determined to assess PCHE enzyme function.
• Measurements were performed on CSF and plasma samples from healthy patients (ASA physical status 1 and 2) and patients with recent intraventricular bleeding.

Main Results:

• Mean PCHE activity in CSF was significantly lower (0.018 units/ml) compared to plasma (0.960 units/ml).
• Mean dibucaine number (DN) in CSF was 59, while in plasma it was 84.
• In patients with intraventricular bleeding, CSF PCHE activity increased markedly (0.340 units/ml), approaching plasma levels, with a slightly elevated DN (78).

Conclusions:

• CSF exhibits substantially lower PCHE activity than plasma, typically 1/20th to 1/100th.
• Intraventricular bleeding leads to a significant elevation of PCHE activity within the CSF.
• These findings highlight the dynamic nature of CSF PCHE and its potential as a biomarker in neurological events involving bleeding.