OBJECTIVES The purpose of this study was to investigate the responses oipatients with primary pulmonary hypertension (PPH) to constant work rate exercise and to examine the effect of nitric oxide (NO) inhalation. BACK...
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OBJECTIVES The purpose of this study was to investigate the responses oipatients with primary pulmonary hypertension (PPH) to constant work rate exercise and to examine the effect of nitric oxide (NO) inhalation. BACKGROUND Maximal exercise tolerance is reduced in PPH, but gas exchange responses to constant work rate exercise have not been defined. We hypothesized that increased pulmonary vascular resistance in PPH would reduce the rate of rise of minute oxygen consumption in response to a given work rate. Because NO may lower pulmonary Vascular pressures in PPH, we also postulated that inhaled NO might ameliorate gas exchange abnormalities. METHODS Nine PPH patients and nine matched normal subjects performed 6-min duration constant work rate cycle ergometry exercise (33.9 +/- 13.4 W). Patients performed two experiments: breathing air and breathing air with NO (20 ppm). Preexercise right ventricular systolic pressure was assessed by Doppler echocardiography. Normal subjects performed the air experiment only. Gas exchange and heart rate responses were characterized by fitting monoexponential curves. RESULTS In PPH patients, resting right ventricular systolic pressure fell after NO inhalation (from 83.8 +/- 16.9 to 73.9 +/- 21.6 mm Hg, p < 0.01, analysis of variance with Tukey correction), but not after breathing air alone (from 88.0 +/- 20.8 to 86.7 +/- 20.6 mm Hg, p = NS). Nitric oxide did not affect any of the gas exchange responses. Minute oxygen consumption was similar by the end of exercise in patients and normals, but increased more slowly in patients (mean response time [MRT]: air, 63.17 +/- 14.99 s;NO, 61.60 +/- 15.45 s) than normals (MRT, 32.73 +/- 14.79, p < 0.01, analysis of variance, Tukey test). Minute oxygen consumption kinetics during recovery were slower in patients (MRT air: 82.50 +/- 29.94 s;NO, 73.36 +/- 15.87 s) than in normals (MRT, 34.59 +/- 7.11 s, p < 0.01). Heart rate kinetics during exercise and recovery were significantly slower in patients
Background Radiocontrast nephropathy (RCN) is a common source of acute renal failure in hospitalized patients and is associated with increased morbidity and mortality rates. Fenoldopam mesylate is a dopomine A1 recept...
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Background Radiocontrast nephropathy (RCN) is a common source of acute renal failure in hospitalized patients and is associated with increased morbidity and mortality rates. Fenoldopam mesylate is a dopomine A1 receptor agonist that augments renal plasma flow (RPF) in patients with normotensive and hypertensive conditions, To determine whether fenoldopam mesylate attenuates reductions in RPF after contrast infusion, we conducted a double-blind, randomized, placebo-controlled pilot trial of fenoldopam mesylate in patients who underwent contrast angiography. Methods Fifty-one patients with chronic renal insufficiency (creatinine level, 2.0-5.0 mg/dL) who were undergoing contrast angiography were screened, and 45 patients were randomized to receive normal saline solution (1/2 NS) or 1/2 NS plus fenoldopam mesylate at 0.1 mug/kg/min at lease I hour before infusion with contrast dye. Serum creatinine level was measured at baseline and at 24, 48, and 72 hours after angiography. The primary endpoint was change in RPF I hour after contrast infusion. The secondary endpoint was incidence of RCN, defined as a 0.5 mg/dL or a 25% rise in serum creatinine level at 48 hours. Results RPF at I hour after angiography was 15.8% above baseline in the fenoldopam mesylate group compared with 33.2% below baseline in the 1/2 NS group (P < .05). The incidence rate of RCN at 48 hours was A 1.0% in the 1/2 NS group versus 21% in the fenoldopam mesylate group (P = .148). Among patients with diabetes, the incidence rate of RCN tended to be higher in the 1/2 NS group compared with the fenoldopam mesylate group (64% vs 33%;P = .14), The peak serum creatinine level at 72 hours after contrast infusion was significantly higher at in the 1/2 NS group (creatinine level, 3.6 +/- 1.0 mg/dL) compared with the fenoldopam mesylate group (creatinine level, 2.8 +/- 0.35 mg/dL;P < .05). RPF was significantly (P < .0001) reduced in patients with RCN compared with patients in whom RCN did not develop. Conclusio
Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male...
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Trimetazidine (TMZ), an anti-ischemic agent with proposed antioxidant properties, was used in a chronic colitis model in order to evaluate its effectiveness as a therapeutic agent in chronic colitis. Treatment of male Swiss Albino rats with ethanol (50%) and trinitrobenzenesulfonic acid (TNBS) (30 mg/kg) produced colitis as evidenced by histopathologic damage and inflammatory alterations, lipid peroxidation [increased malondialdehyde (MDA) levels], and enhanced neutrophil infiltration [increased myeloperoxidase (MPO) activity] without marked change in glutathione status. Administration of TMZ (5 mg/kg) to TNBS-treated rats failed to affect the TNBS-induced changes in histopathology and MPO activities. Unexpectedly, intrarectal (ir) administration of TMZ significantly elevated colonic MDA levels to a greater extent than TNBS alone. Intraperitoneal (ip) TMZ treatment seemed to increase total glutathione (tGSH), GSH, and GSH/GSSg values. In conclusion, our results demonstrated that (a) ir administration of ethanol and TNBS is an effective way of inducing a chronic colitis model, (b) inflammation and lipid peroxidation augment tissue damage in the chronic colitis model, (c) ip TMZ treatment significantly inhibits MDA production in the chronic colitis model, (d) TMZ treatment is more effective via the ip compared to ir route, and (e) TMZ seems to show its antioxidant effect via preserving the tissue's GSH/GSSG ratios.
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