Morphine and codeine are endogenous components of human cerebrospinal fluid

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Opioid peptides are endogenous signaling molecules found in the central nervous system.
• The presence and origin of exogenous or endogenous morphine and codeine in cerebrospinal fluid (CSF) are not fully understood.

Purpose of the Study:

• To investigate the presence and concentration of morphine and codeine in the CSF of individuals not receiving any medication.
• To compare the levels of these alkaloids to endogenous opioid peptide concentrations in spinal fluid.

Main Methods:

• Analysis of cerebrospinal fluid (CSF) samples from twelve medication-free patients.
• Quantification of morphine and codeine concentrations using sensitive analytical techniques.
• Assessment of the conjugated state of the alkaloids and their release via acid hydrolysis.

Main Results:

• Morphine and codeine were detected in the CSF of all twelve patients studied.
• Concentrations ranged from 2 to 339 fmol/ml, comparable to endogenous opioid peptide levels.
• The majority of morphine and codeine were found in conjugated forms, releasable by acid hydrolysis.

Conclusions:

• The human central nervous system may contain endogenous or exogenously acquired morphine and codeine.
• These findings suggest a potential role for these alkaloids in neurological processes or as indicators of specific physiological states.