ozagrel and dazmegrel

Tumor necrosis factor alpha (TNF alpha) and thromboxane A2 (TXA2) are major products of the activated alveolar macrophage and serve as key mediators of lung injury. In order to determine if the synthesis of TXA2 and the release of TNF alpha are associated, the production of these inflammatory agents by the human alveolar macrophage (AM), as a result of activation by lipopolysaccharide (LPS), was assessed in the absence and presence of the thromboxane synthase inhibitors UK 38,485 (Dazmegrel) and OKY 046. UK 38,485 and OKY 046 inhibited both LPS-stimulated TXA2 production and TNF alpha release in a dose-dependent manner. Prostaglandin E2 (PGE2) production was not increased by UK 38,485 or OKY 046. Neither LPS nor UK 38,485 had any effect on LTB4 production by AM. Neither UK 38,485 or OKY 046 had any effect on LPS-stimulated interleukin-1 beta release. However, the TXA2 mimetic, U46619, did not stimulate TNF alpha release by AM either in the absence or presence of UK 38,485. These findings suggest that 1) UK 38,485 and OKY 046 are inhibitors of both TXA2 production and TNF alpha release by activated human AM, 2) UK 38,485 probably does not exert its inhibitory action on TNF alpha release through effects on eicosanoid production and 3) the possibility that TNF alpha- and TXA2-induced lung injury may be subject to amelioration by imidazole-based compounds should be further evaluated.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Adult; Cells, Cultured; Humans; Imidazoles; Kinetics; Lipopolysaccharides; Macrophage Activation; Macrophages, Alveolar; Male; Methacrylates; Middle Aged; Prostaglandin Endoperoxides, Synthetic; Thromboxane A2; Thromboxane-A Synthase; Tumor Necrosis Factor-alpha; Vasoconstrictor Agents

To determine whether the increased renal biosynthesis of thromboxane A2 observed in young genetically hypertensive rats of the Lyon strain could be involved in the development of their hypertension, Lyon hypertensive female rats received either thromboxane synthetase inhibitors (Dazmegrel or OKY 046) or a thromboxane A2 receptor antagonist (AH 23848) during their prehypertensive stage. Treatment from 5 to 9 weeks of age with Dazmegrel failed to reduce systolic blood pressure. When given from 3 to 9 weeks of age, Dazmegrel and OKY 046 induced a similar progressive and specific reduction (60%) in the urinary excretion of thromboxane B2 that was associated with a transient decrease in blood pressure level with Dazmegrel and a longer lasting blood pressure-lowering effect with OKY 046. AH 23848, given according to the same schedule, normalized the blood pressure level. This effect persisted 1 week after the cessation of the treatment. Interestingly, active doses of thromboxane synthetase inhibitors or of thromboxane A2 receptor blocker required a 3-week delay to exhibit their antihypertensive properties. It is concluded that 1) the elevated production of thromboxane A2 observed in young Lyon hypertensive rats is likely to participate actively in their blood pressure regulation and 2) this effect may be independent of its direct vasoconstrictor properties.

Topics: Animals; Biphenyl Compounds; Female; Hypertension; Imidazoles; Methacrylates; Rats; Rats, Mutant Strains; Receptors, Prostaglandin; Receptors, Thromboxane; Thromboxane A2; Thromboxane-A Synthase

Pretreatment with the thromboxane synthase inhibitor OKY-046 but not the cyclo-oxygenase inhibitor ibuprofen protects against ischemia-induced acute tubular necrosis. However, ibuprofen together with the vasodilating agent prostaglandin E1 is protective. This suggests that a high prostaglandin to thromboxane ratio is the major factor operative in preventing tubular necrosis, the subject of this study. Rats that had unilateral nephrectomy (n = 60) with the exception of rats that had sham operations (n = 8) underwent 45 minutes of left renal pedicle clamping. Thirty minutes before the operation, the rats received either a saline solution or a thromboxane synthase inhibitor that was given intravenously. The inhibitors OKY-046 (2 milligrams per kilogram, n = 10), UK38485 (1 milligram per kilogram, n = 9) and U63357A (10 milligrams per kilogram, n = 10) were given as a single bolus while the inhibitor CGS13080 (0.1 milligram per kilogram, n = 9, and 1.0 milligram per kilogram, n = 7) was given by constant infusion and continued for 60 minutes after reperfusion. With saline solution therapy, five minutes after reperfusion, thromboxane B2 increased from 154 to 2,537 picograms per milliliter (p less than 0.00001) and 6-keto-prostaglandin F1 alpha increased from 51 to 266 picograms per milliliter (p less than 0.004). At 24 hours, the creatinine level increased from 0.5 to 2.8 milligrams per deciliter (p less than 0.00001). Only OKY-046 yielded a creatinine level at 24 hours of 1.2 milligrams per deciliter, a value lower than that for those in the saline solution control group (p less than 0.002). Furthermore, OKY-046 led to the highest prostaglandin to thromboxane ratio (p less than 0.035). The five other ratios which occurred after drug therapy were inversely related to the decrease in the creatinine value (r = -0.93, p less than 0.02). Histologically, OKY-046 was the only thromboxane synthase inhibitor to prevent acute tubular necrosis (p less than 0.05). Results show that a high prostaglandin to thromboxane ratio protects against acute tubular necrosis.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Benzofurans; Creatinine; Evaluation Studies as Topic; Ibuprofen; Imidazoles; Ischemia; Kidney; Kidney Tubular Necrosis, Acute; Male; Methacrylates; Pyridines; Rats; Thromboxane B2; Thromboxane-A Synthase