Rat Brain-Uptake Index for Phenylethylamine and Various Monomethylated Derivatives

• Published in: Neurochemical research Vol. 38; no. 4; pp. 842 - 846
• Main Authors: Mosnaim, Aron D., Callaghan, Owen H., Hudzik, Thomas, Wolf, Marion E.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.04.2013; Springer Nature B.V
• Subjects: Amphetamine; Amphetamine - pharmacokinetics; Animals; Biochemistry; Biomedical and Life Sciences; Biomedicine; Blood-Brain Barrier - metabolism; Brain - metabolism; Carbon Radioisotopes; Cell Biology; Male; Methamphetamine - analogs & derivatives; Methamphetamine - pharmacokinetics; Neurochemistry; Neurology; Neurosciences; Original Paper; Phenethylamines - pharmacokinetics; Rats; Rats, Sprague-Dawley; Tritium; Phenylethylamine; Amphetamine; Blood-brain barrier; Brain-uptake index; Monomethylated phenylethylamine derivatives
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1007/s11064-013-0988-1

Phenylethylamine and its monomethylated derivatives p -methylphenylethylamine, α-methylphenylethylamine, phenylethylamine itself, N -methylphenylethylamine, o -methylphenylethylamine, and β-methylphenylethylamine, readily cross the blood-brain barrier showing a brain-uptake index (%) ± SD (water considered 100 %), of 108 ± 11, 98 ± 14, 83 ± 6, 78 ± 11, 62 ± 7 and 56 ± 6, respectively (injection of tritiated water and 100 μg standard amine, which was measured by gas-liquid chromatography). Similar brain-uptake index values (determined by double isotope counting) were obtained for phenylethylamine and α-methylphenylethylamine (amphetamine) after the injection of tritiated water and C 14 -labeled amine (either 3 μg or when added 100 μg standard compound), suggesting that they entered the brain via passive diffusion. Accordingly, both amines distributed rather evenly in the various rat brain areas examined: uptake index (%) ± SD (double isotope counting; non-, and diluted labeled amine) for phenylethylamine (89 ± 8 and 78 ± 7, 83 ± 9 and 86 ± 9, 96 ± 6 and 84 ± 7) and for α-methylphenylethylamine (88 ± 11 and 87 ± 9, 93 ± 14 and 87 ± 11, 97 ± 12 and 87 ± 9) for the cerebellum, frontal cortex, and striatum, respectively. These results will aid a greater understanding of the pharmacological and behavioral effects observed after the administration of phenylethylamine and methylphenylethylamine derivatives.