N-docosahexaenoyl, 3 hydroxytyramine: a dopaminergic compound that penetrates the blood-brain barrier and suppresses appetite.

Fatty acids with varying chain lengths (2-22 carbon atoms long) and degrees of unsaturation (0-6 double bonds) were used to synthesize dopaminergic compounds for a study of the carrier mediated transport of dopamine (DA) to the brain. The most active carrier was the all cis C22:6 fatty acid [docosahexaenoic acid, (DHA)]which increased DA uptake through the blood-brain barrier by greater than 7.5 fold. The DHA-DA compound, NMI 8739, depressed the general locomotor activity of mice in a dose dependent manner. It also suppressed the appetite of Balb c mice and Charles River rats by 50% and 95% respectively at a dose of 10 mg/kg. Daily administration of NMI-8739 for a three week period did not induce tolerance. These results demonstrate DHA's potential for the carrier mediated transport of small molecules to the brain.