Behavioral evidence for the interaction of oleamide with multiple neurotransmitter systems.

While the endogenous fatty acid amide oleamide has hypnotic properties, neither the breadth of its behavioral actions nor the mechanism(s) by which these behaviors may be mediated has been elucidated. Therefore, the effects of oleamide on the performance of rats in tests of motor function, analgesia, and anxiety were investigated. Oleamide reduced the distance traveled in the open field (ED50 = 14, 10-19 mg/kg, mean, 95% confidence interval), induced analgesia and hypothermia, but did not cause catalepsy. Moreover, a dose of oleamide without effect on motor function was anxiolytic in the social interaction test and elevated plus-maze. These actions of a single dose of oleamide lasted for 30 to 60 min. While rats became tolerant to oleamide following 8 days of repeated administration, oleamide is a poor inducer of physical dependence. Pretreatment with antagonists of the serotonin (5HT)1A, 5HT2C, and vanilloid receptors did not modify oleamide's effects. However, the cannabinoid receptor antagonist SR 141716A inhibited oleamide-induced analgesia in the tail-flick assay, the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline reversed the analgesia and hypothermia, and the dopamine D2 receptor antagonist L 741626 blocked oleamide's locomotor and analgesic actions. Interestingly, oleamide analogs resistant to hydrolysis by fatty acid amide hydrolase (FAAH) maintained but did not show increased behavioral potency or duration of action, whereas two FAAH inhibitors produced analogous behavioral effects. Thus, oleamide induces behaviors reminiscent of the actions of endogenous cannabinoids, but the involvement of GABAergic and dopaminergic systems, either directly or indirectly, in the actions of oleamide cannot be ruled out.

Fatty acid amide hydrolase substrate specificity.

Fatty acid amide hydrolase (FAAH), also referred to as oleamide hydrolase and anandamide amidohydrolase, is a serine hydrolase responsible for the degradation of endogenous oleamide and anandamide, fatty acid amides that function as chemical messengers. FAAH hydrolyzes a range of fatty acid amides, and the present study examines the relative rates of hydrolysis of a variety of natural and unnatural fatty acid primary amide substrates using pure recombinant rat FAAH.

Exceptionally potent inhibitors of fatty acid amide hydrolase: the enzyme responsible for degradation of endogenous oleamide and anandamide.

The development of exceptionally potent inhibitors of fatty acid amide hydrolase (FAAH), the enzyme responsible for the degradation of oleamide (an endogenous sleep-inducing lipid), and anandamide (an endogenous ligand for cannabinoid receptors) is detailed. The inhibitors may serve as useful tools to clarify the role of endogenous oleamide and anandamide and may prove to be useful therapeutic agents for the treatment of sleep disorders or pain. The combination of several features-an optimal C12-C8 chain length, pi-unsaturation introduction at the corresponding arachidonoyl Delta(8,9)/Delta(11,12) and oleoyl Delta(9,10) location, and an alpha-keto N4 oxazolopyridine with incorporation of a second weakly basic nitrogen provided FAAH inhibitors with K(i)s that drop below 200 pM and are 10(2)-10(3) times more potent than the corresponding trifluoromethyl ketones.

The search for orally active medications through combinatorial chemistry.

The literature of combinatorial chemistry is reviewed with particular attention paid to considerations of absorption, distribution, metabolism and excretion in the design and evaluation of libraries containing drug-like molecules. Published libraries are evaluated in particular for the likelihood that the products would possess oral bioavailability.