Nonselective cyclooxygenase (COX) inhibitors are potent tocolytic agents but have adverse effects on the fetal ductus arteriosus. We hypothesized that COX-2 inhibitors may not affect the ductus if the predominant COX isoform is COX-1. To examine this hypothesis, we used ductus arteriosus obtained from late-gestation fetal lambs. In contrast to our hypothesis, fetal lamb ductus arteriosus expres...

The cyclooxygenase (COX)-2 inhibitors 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5II)-furanone (DFU) (0.02-2 mg/kg) and N-[2-(cyclohexyloxy)-4-nitrofenyl]-methanesulfonamide (NS-398) (0.01-1 mg/kg), the COX-1 inhibitor 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole (SC-560) (0.05-5 mg/kg), and dexamethasone (1 mg/kg) were studied in rats challenged with intra...

Previous studies indicate that the arachidonic acid-metabolizing enzymes COX-2 and 5-LOX are overexpressed during the process of colonic adenoma formation promoted by cigarette smoke. The aims of the present study were to investigate whether there exists a relationship between COX-2 and 5-LOX, and whether dual inhibition of COX-2 and 5-LOX has an anticarcinogenic effect in the colonic tumorigen...

Nonselective blockade of the cyclooxygenase (COX) enzymes in skeletal muscle eliminates the normal increase in muscle protein synthesis following resistance exercise. The current study tested the hypothesis that this COX-mediated increase in postexercise muscle protein synthesis is regulated specifically by the COX-2 isoform. Sixteen males (23 +/- 1 yr) were randomly assigned to one of two grou...

OBJECTIVE Cyclooxygenase-1 (COX-1), but not COX-2, is expressed in human platelets, and thromboxane A2 (TXA2) produced via COX-1 induces platelet aggregation. The objectives of this study were to investigate the expression of COX-1 and COX-2 during platelet differentiation and to determine whether these enzymes are involved in the differentiation. METHODS AND RESULTS CD34+ progenitor cells is...

The proinflammatory cytokine interleukin-1beta (IL) stimulates inducible nitric oxide synthase (iNOS) mRNA, protein, and nitric oxide (NO) production in neonatal ventricular myocytes (NVM). In other types of cells, IL also activates phospholipase A2 (PLA2), which liberates arachidonic acid for the pathways involved in eicosanoid production, and induces the cyclooxygenase-2 (COX-2) isoform, whic...

Prostaglandin E(2) may antagonize vasopressin-stimulated salt absorption in the thick ascending limb and water absorption in the collecting duct. Blockade of prostaglandin E(2) synthesis by nonsteroidal anti-inflammatory drugs (NSAIDs) enhances urinary concentration, and these agents have antidiuretic effects in patients with nephrogenic diabetes insipidus (NDI) of different etiologies. Because...