l-745337 and nimesulide

Vascular smooth muscle is now recognized as an important site of mediator generation under inflammatory conditions. Indeed, the release of leukocyte activators, such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-8, by human arterial smooth muscle cells has recently been demonstrated. However, the potential for venous cells to release GM-CSF has not been addressed. We have shown that human vascular smooth muscle cells express the "inflammatory" form of cyclooxygenase (COX), cyclooxygenase-2 (COX-2), when stimulated with cytokines. In some nonvascular cell types, the COX activity has been shown to regulate the release of GM-CSF and IL-8, although the nature of the isoform responsible was not addressed. We show that human venous smooth muscle cells, like their arterial counterparts, release GM-CSF after stimulation with IL-1beta. Similarly, both cell types released IL-8. Under the same conditions, we found that COX-2 activity suppressed GM-CSF, but not IL-8, release by both types of human vascular cells. Moreover, the prostacyclin mimetic, cicaprost, and the cAMP analogue, dibutyryl cAMP, inhibited GM-CSF release from these cells. These observations suggest that COX-2 activity suppresses GM-CSF release via a cAMP-dependent pathway in human vascular cells and illustrates a novel mechanism by which this enzyme can modulate immune and inflammatory events.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Arteriosclerosis; Aspirin; Bucladesine; Cells, Cultured; Cyclic AMP; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprostone; Epoprostenol; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Indans; Indomethacin; Interleukin-1; Interleukin-8; Isoenzymes; Mammary Arteries; Meloxicam; Membrane Proteins; Muscle, Smooth, Vascular; Neutrophils; Prostaglandin-Endoperoxide Synthases; Saphenous Vein; Sulfonamides; Thiazines; Thiazoles; Tumor Necrosis Factor-alpha

1. In this study we describe experiments to establish ex vivo the selectivity of non-steroidal anti-inflammatory drugs (NSAIDs) given in vivo. 2. Anaesthetised (Inactin, 120 mg kg(-1)) male Wistar rats (220-250 g) received an i.v. dose of one of the following compounds (dose mg kg(-1)): aspirin (20), diclofenac (3), L-745,337 (30), nimesulide (15), salicylate (20), sulindac (10). Blood samples were taken before and up to 6 h after dosing and the plasma obtained from it was tested for its ability to inhibit prostanoid formation in IL-1beta-treated A549 cells (COX-2 system) and human washed platelets (COX-1 system). For control the same compounds were also added directly to the assay systems. 3. All drugs, except sodium salicylate, inhibited COX-1 and COX-2 when added directly to the test systems. Plasma from aspirin-treated rats was without effect on either COX-1 or COX-2, consistent with the rapid in vivo metabolism to salicylate. Conversely, plasma from sulindac-treated rats inhibited COX-1 and COX-2 with potencies according with in vivo metabolism to sulindac sulphide. Diclofenac was COX-1/2 non-selective when tested in vitro, but a slightly preferential inhibitor of COX-2 when tested ex vivo. Nimesulide was confirmed as preferential inhibitor of COX-2 both in vitro and ex vivo. L-745,337 was a selective COX-2 inhibitor when tested in vitro or ex vivo. 4. In conclusion, our experiments show clearly (a) NSAIDs inactivation, (b) activation of prodrugs, and (c) NSAIDs selectivity. Our assay provides useful information about the selectivity of NSAIDs that could be extended by the analysis of plasma samples taken from humans similarly treated with test drugs.

Topics: Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Blood Platelets; Blood Pressure; Carcinoma; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Diclofenac; Dinoprostone; Humans; Indans; Isoenzymes; Male; Membrane Proteins; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Salicylates; Substrate Specificity; Sulfonamides; Sulindac; Thromboxane B2; Tumor Cells, Cultured

Pretreatment of mice with lipopolysaccharide for 16 h enhanced the number of acetic acid-induced writhing reactions by 2 to 3-fold. In the peritoneal exudates at 10 min after acetic acid injection, 6-keto-prostaglandin F1alpha was detected as a major prostanoid, and this level increased by several-fold by the pretreatment with lipopolysaccharide. The writhing reaction and the prostaglandin formation were almost completely suppressed by indomethacin. However, the lipopolysaccharide-induced enhancement of writhing reaction and an increment of 6-keto-prostaglandin F1alpha level were diminished by the administration of cyclooxygenase-2-selective inhibitors, such as NS-398, nimesulide, or L-745337, to a level similar to the mice that did not receive lipopolysaccharide. Cyclooxygenase-2 protein in the exudates became detectable at 5-48 h after the lipopolysaccharide-pretreatment. These results suggest that the increased prostaglandin production by cyclooxygenase-2 could be responsible for enhancement of the acetic acid-induced writhing reaction by lipopolysaccharide pretreatment.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Enzyme Induction; Exudates and Transudates; Indans; Indomethacin; Isoenzymes; Male; Mice; Mice, Inbred ICR; Nitrobenzenes; Pain; Pain Measurement; Peritoneum; Prostaglandin-Endoperoxide Synthases; Sulfonamides