11-dehydro-thromboxane-b2 and Body-Weight

This multicenter, double-blind, randomized, placebo-controlled, parallel-group study assessed renal function during dosing with etoricoxib 90 mg daily, celecoxib 200 mg twice daily, and naproxen 500 mg twice daily. Male and female subjects 60 to 81 years old (n = 85), in sodium balance on a controlled, normal sodium diet, were treated for 15 days. There were no clinically meaningful between-treatment differences in urinary sodium excretion, creatinine clearance, body weight, or serum electrolytes during the 2 weeks of treatment. Etoricoxib and celecoxib had no effect on the urinary thromboxane metabolite, 11-dehydrothromboxane B(2), while significantly decreasing the urinary prostacyclin metabolite, 2,3-dinor-6-keto PGF(1alpha). Decreases were greater for both metabolites following naproxen. Ambulatory systolic blood pressures were significantly higher than placebo for all treatments, with moderately greater increases for etoricoxib relative to other active treatments on day 14. Ambulatory diastolic blood pressures were significantly higher than placebo for etoricoxib and naproxen but not for celecoxib.

Topics: 6-Ketoprostaglandin F1 alpha; Administration, Oral; Aged; Aged, 80 and over; Anti-Inflammatory Agents, Non-Steroidal; Blood Pressure; Body Weight; Celecoxib; Constipation; Creatinine; Diarrhea; Dose-Response Relationship, Drug; Double-Blind Method; Electrolytes; Etoricoxib; Female; Headache; Humans; Male; Middle Aged; Naproxen; Potassium; Prostaglandins; Pyrazoles; Pyridines; Sodium; Sulfonamides; Sulfones; Thromboxane B2

Intermittent hypoxia, the main stimulus of obstructive sleep apnoea (OSA), induces inflammation, leading to early atherosclerosis. Whether the cyclooxygenase (COX) pathway contributes to intermittent hypoxia-induced atherosclerosis remains to be determined. We studied the effects of 8-weeks of intermittent hypoxia exposure on COX-pathway gene expression and atherosclerosis, and the influence of COX-1 inhibition by SC-560 on atherosclerosis progression in aortas of apolipoprotein E(-/-) mice. Urinary 11-dehydrothromboxane B2 (11-dTXB2) was assessed in 50 OSA subjects free of cardiovascular risk factor matched for age and body mass index with 25 controls, and 56 OSA with cardiovascular risk factor. Intermittent hypoxia significantly increased atherosclerotic lesion sizes, mRNA levels of COX-1 and thromboxane synthase (TXBS). Lesion sizes correlated to COX-1 (r = 0.654, p = 0.0003) and TXBS (r = 0.693, p<0.0001) mRNA levels. COX-1 inhibition reduced lesion progression in intermittent hypoxia mice only (p = 0.04). Urinary 11-dTXB2 was similar in OSA subjects free of cardiovascular risk factor and controls, but was increased by 13% (p = 0.007) in OSA subjects with cardiovascular risk factor compared with those without. Although OSA itself was not associated with increased urinary 11-dTXB2 concentration, the COX-1 pathway was activated in intermittent hypoxia-exposed mice and in OSA subjects presenting with cardiovascular risk factor, and may contribute to intermittent hypoxia-induced atherogenesis. COX-1 inhibition could be of clinical interest in the prevention of cardiovascular morbidity in OSA.

Topics: Adult; Animals; Aorta; Apolipoproteins E; Atherosclerosis; Body Mass Index; Body Weight; Case-Control Studies; Cyclooxygenase 1; Cyclooxygenase Inhibitors; Female; Gene Expression Regulation, Enzymologic; Hematocrit; Humans; Hypoxia; Male; Mice; Mice, Transgenic; Middle Aged; Pyrazoles; Risk Factors; Sleep Apnea, Obstructive; Thromboxane B2

The effects of exercise training on eicosanoid levels were studied in male Wistar rats. One-month-old rats were trained on a drum exerciser at an intensity of around 70% of maximal oxygen consumption for 10 weeks (60 min day-1, 5 days week-1) after familiarization. Some animals of the same age did not exercise and served as a control. Two days after training, several blood vessels, including thoracic aortae, inferior vena cavae, external iliac arteries, external iliac veins, common carotid arteries and jugular veins, were excised and incubated for 10 min. Basal release of prostacyclin from these vessels was determined using [125I]radio-immunoassay (RIA) of 6-keto-PGF1 alpha. The levels of plasma prostacyclin and urinary metabolites of prostacyclin and thromboxane were also determined by RIA. Our results showed that trained animals had lower body weight and urine 11-dehydro-thromboxane B2 levels than the controls (P < 0.001 and P < 0.05, respectively). In contrast, urinary 2,3-dinor-6-keto-PGF1 alpha level was elevated after training (P < 0.05). Nonetheless, prostacyclin levels in plasma and from various dissected vessel segments, except thoracic aorta, did not change significantly after training. These findings suggest that exercise training may affect endogenous eicosanoid levels by increasing the basal release of prostacyclin and reducing the basal thromboxane level.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Blood Cell Count; Body Weight; Epoprostenol; Male; Muscle, Smooth, Vascular; Oxygen Consumption; Physical Exertion; Pulmonary Gas Exchange; Rats; Rats, Wistar; Thromboxane B2; Thromboxanes