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Published on: November 30, 2012
Agmatine crosses the blood-brain barrier
1University of Mississippi Medical Center, Jackson, Mississippi 39216, USA.
Annals of the New York Academy of Sciences
|March 19, 2004
Summary
Agmatine and its precursor, arginine, can cross the blood-brain barrier, as demonstrated by increased brain and cerebrospinal fluid levels after administration in mice and monkeys. This finding supports agmatine
Area of Science:
- Neuroscience
- Pharmacology
- Biochemistry
Background:
- The ability of agmatine to cross the blood-brain barrier remains unconfirmed, despite observed behavioral effects in various neurological paradigms.
- Peripheral administration of agmatine has shown potential in models of drug withdrawal, depression, and anxiety.
Purpose of the Study:
- To investigate whether agmatine and its precursor, arginine, can cross the blood-brain barrier.
- To quantify agmatine levels in brain tissue and cerebrospinal fluid following systemic and central administration.
Main Methods:
- Mice received intraperitoneal injections of agmatine or arginine, with subsequent whole-brain agmatine measurement via HPLC.
- Rhesus monkeys received intravenous or intracerebroventricular injections of agmatine or arginine, with subsequent analysis of cerebrospinal fluid and plasma agmatine levels.
Main Results:
- Agmatine levels in mouse brains increased significantly after intraperitoneal administration of 50 and 300 mg/kg.
- In monkeys, intravenous agmatine and arginine led to detectable agmatine levels in cerebrospinal fluid, correlating with plasma concentrations.
- Intracerebroventricular agmatine administration in monkeys resulted in a sustained elevation of plasma agmatine for over 24 hours.
Conclusions:
- Both agmatine and arginine are capable of crossing the blood-brain barrier.
- Cerebrospinal fluid agmatine levels may originate from newly synthesized agmatine from peripherally administered arginine.
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