bimatoprost and nimesulide

Endocannabinoids are protective in animal colitis models. As endocannabinoids also form novel prostaglandin ethanolamides (prostamides) via COX-2, we investigated the effects of prostamides and other COX-2 mediators on tissue damage in an ex vivo human mucosal explant colitis model. Healthy human colonic mucosae were incubated with pro-inflammatory cytokines TNF-α and IL-1β to elicit colitis-like tissue damage. The PGF-ethanolamide analogue, bimatoprost decreased colitis scores which were reversed by a prostamide-specific antagonist AGN 211334, but not the FP receptor antagonist AL-8810. PGF-ethanolamide and PGE-ethanolamide also reduced cytokine-evoked epithelial damage. Anandamide was protective in the explant colitis model; however COX-2 inhibition did not alter its effects, associated with a lack of COX-2 induction in explant mucosal tissue. These findings support an anti-inflammatory role for prostamides and endocannabinoids in the human colon.

Topics: Adult; Amides; Arachidonic Acids; Bimatoprost; Cloprostenol; Colitis; Colon, Sigmoid; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Dinoprost; Dinoprostone; Endocannabinoids; Female; Humans; Immunohistochemistry; Interleukin-1beta; Male; Middle Aged; Oxazoles; Polyunsaturated Alkamides; Receptors, Prostaglandin; Sulfonamides; Tissue Culture Techniques; Tumor Necrosis Factor-alpha; Young Adult

We investigated the contribution of cyclo-oxygenase enzyme inhibition and prostamide agonism on human colonic contractility in vitro. The effects of the non-specific COX inhibitor diclofenac were compared against selective COX-2 inhibition via nimesulide, the prostanoid EP(1) receptor antagonist SC19220 or the prostaglandin prodrug/prostamide receptor agonist bimatoprost, on potency of contraction to acetylcholine in human colonic circular and longitudinal muscle strips. Pre-treatment with either nimesulide (10(-5)M) or diclofenac (10(-6)M) caused a significant decrease in the potency of acetylcholine-evoked longitudinal muscle contraction, but did not inhibit acetylcholine-evoked circular muscle contraction. Pre-treatment with the EP(1) receptor antagonist SC19220 (10(-5)M) similarly decreased cholinergic potency in longitudinal muscle, without influence on circular muscle contraction. The prostamide agonist bimatoprost (10(-6)M) increased basal circular and longitudinal muscle tone, but did not alter cholinergic potency in either muscle layer. In conclusion, colonic longitudinal muscle contraction is augmented by COX-2 activity, most likely via PGE(2) acting at EP(1) receptors. While colonic contraction is tonically modulated by bimatoprost, it does not share the same functional properties attributed to other endogenous COX-2 metabolites on colonic contractile function.

Topics: Acetylcholine; Amides; Bimatoprost; Cloprostenol; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Diclofenac; Humans; In Vitro Techniques; Muscle Contraction; Muscle, Skeletal; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP1 Subtype; Sulfonamides