873079-69-7Relevant articles and documents
Systemic and intrathecal effects of a novel series of phospholipase A 2 inhibitors on hyperalgesia and spinal prostaglandin E2 release
Yaksh, Tony L.,Kokotos, George,Svensson, Camilla I.,Stephens, Daren,Kokotos, Christoforos G.,Fitzsimmons, Bethany,Hadjipavlou-Litina, Dimitra,Hua, Xiao-Ying,Dennis, Edward A.
, p. 466 - 475 (2006)
Phospholipase A2 (PLA2) forms are expressed in spinal cord, and inhibiting spinal PLA2 induces a potent antihyperalgesia. Here, we examined the antihyperalgesic effects after systemic and i.t. delivery of four compounds constructed with a common motif consisting of a 2-oxoamide with a hydrocarbon tail and a four-carbon tether. These molecules were characterized for their ability to block group IVA calcium-dependent PLA 2 (cPLA2) and group VIA calcium-independent PLA 2 (iPLA2) in inhibition assays using human recombinant enzyme. The rank ordering of potency in blocking group IVA cPLA2 was AX048 (ethyl 4-[(2-oxohexadecanoyl)amino]butanoate), AX006 (4-[(2- oxohexadecanoyl)amino]butanoic acid), and AX057 (tert-butyl-4-[(2- oxohexadecanoyl)amino]butanoate) > AX010 (methyl 4-[(2-oxohexadecanoyl)amino] butanoate) and for inhibiting group VIA iPLA2 was AX048, AX057 > AX006, and AX010. No agent altered recombinant cyclooxygenase activity. In vivo, i.t. (30 μg) and systemic (0.2-3 mg/kg i.p.) AX048 blocked carrageenan hyperalgesia and after systemic delivery in a model of spinally mediated hyperalgesia induced by i.t. substance P (SP). The other agents were without activity. In rats prepared with lumbar i.t. loop dialysis catheters, SP evoked spinal prostaglandin E2 (PGE2) release. AX048 alone inhibited PGE2 release. Intrathecal SR141617, a cannabinoid CB1 inhibitor at doses that blocked the effects of i.t. anandamide had no effect upon i.t. AX048. These results suggest that AX048 is the first systemically bioavailable compound with a significant affinity for group IVA cPLA 2, which produces a potent antihyperalgesia. The other agents, although demonstrating enzymatic activity in cell-free assays, appear unable to gain access to the intracellular PLA2 toward which their action is targeted. Copyright