Research communications in chemical pathology and pharmacology
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Res. Commun. Chem. Pathol. Pharmacol. · Nov 1991
Effects of combination therapy with low-dose aspirin and warfarin on platelet functions after heart valve replacement.
To evaluate the efficacy and safety of combination therapy with aspirin and warfarin for preventing the development of thromboembolism, we compared the effects of low-dose aspirin (81 mg/day) on platelet functions to those of ticlopidine (300 mg/day) in heart valve replacement patients. Experiments were performed in two groups; the first group within 1 month after operation (the unstable period) and the second group between 3 months and 3 years after operation (the stable period). At the stable period, low-dose aspirin inhibited platelet aggregation induced by ADP, collagen, or arachidonic acid, and suppressed the increase in intracellular Ca2+ concentration [( Ca2+]i) induced by thrombin significantly. ⋯ And low-dose aspirin inhibited platelet aggregation induced by ADP, collagen or epinephrine, and especially blocked arachidonic acid-induced aggregation. Ticlopidine inhibited ADP-, collagen- or U-46619-induced aggregation, but did not affect on the increase in [Ca2+]i induced by thrombin. From the results in this study, we suggest that the combination therapy with low-dose aspirin (81 mg/day) and warfarin is safe as an antithrombotic medication in heart valve replacement, and results in the inhibition of platelet functions without any side effect calling for special mention at the early unstable period after operation.
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Res. Commun. Chem. Pathol. Pharmacol. · Oct 1991
Comparative Study Clinical Trial Controlled Clinical TrialPlatelet alpha-2 adrenoreceptor activity pre-treatment and post-treatment in major depressive disorder with melancholia.
Changes in alpha-2 adrenoreceptor density and affinity during antidepressant treatment were studied using 3H-yohimbine binding to human platelet membranes. Baseline measurements were conducted in 21 patients diagnosed as having major depressive disorder with melancholia, and an equal number of age and sex matched normal controls. ⋯ Subjects participated for 6 weeks in a trial of placebo, adinazolam, or amitriptyline. Alpha-2 adrenoreceptor binding was not significantly changed from baseline following antidepressant treatment.
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Res. Commun. Chem. Pathol. Pharmacol. · Nov 1988
Polyamine content in pulmonary arteries from rats with monocrotaline-induced pulmonary hypertension.
Based on the documented role of polyamines in regulation of cell growth and differentiation, we have proposed that these organic cations are essential for hypertrophic and hyperplastic responses of pulmonary vascular cells which underlie development of hypertensive pulmonary vascular disease. In support of this contention, we have shown in rat models of monocrotaline (MCT)- and chronic hypoxia-induced pulmonary hypertension that whole-lung polyamine contents are elevated and that blockade of polyamine synthesis forestalls development of hypertensive pulmonary vascular remodeling and sustained pulmonary hypertension. To determine if the involvement of polyamines in pulmonary hypertension could be ascribed to events occurring in cells of the vascular wall, as opposed to parenchymal or airways cells, the present study measured polyamine contents as a function of time in macroscopic pulmonary arteries from MCT-treated rats. ⋯ In pulmonary arterial segments, contents of putrescine and spermidine were augmented significantly at 7 and 21 days after MCT treatment. Spermine content in arterial segments was increased at 21 days. Right ventricular hypertrophy indicative of sustained pulmonary hypertension was not evident until 21 days post-treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Res. Commun. Chem. Pathol. Pharmacol. · May 1988
Echocardiographic detection of pulmonary hypertension in anesthetized rats.
Evaluation of pulmonary arterial pressure in small laboratory animals requires surgical catheter implantation. However, even this modest surgical procedure is known to retard weight gain, alter various biochemical parameters and may exert other deleterious actions which could complicate data interpretation. To obviate these adverse effects of surgery and to permit better staging of experimental procedures, a method for non-invasive detection of pulmonary hypertension would be desirable. ⋯ At sacrifice, the extent of right ventricular hypertrophy was determined as the ratio of the weight of the right ventricular free wall to that of the left ventricle plus septum. Right ventricular systolic time intervals, determined from the echocardiogram, correlated significantly with the extent of right ventricular hypertrophy (p = 0.05; r2 = 0.39) but not with mean pulmonary arterial pressure (p = 0.2; r2 = 0.14). Echocardiography may provide a simple, non-invasive means to detect cardiopulmonary abnormalities in rats and may thus be useful in staging subsequent experimental procedures without need for prior surgical catheter implantation.
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Res. Commun. Chem. Pathol. Pharmacol. · Feb 1981
Effect of endotoxin on thiourea induced pulmonary edema and pleural effusion.
Administration of endotoxin prior to an LD50 dose of thiourea protected rats against pulmonary edema and pleural effusion. These results are similar to those seen with endotoxin pretreatment and pulmonary O2 toxicity.