Search results for "RATS"
showing 10 items of 3537 documents
Incorporation and metabolism of dietary trans isomers of linolenic acid alter the fatty acid profile of rat tissues
2000
To study the influence on lipid metabolism and platelet aggregation of the fatty acid isomerization that occurs during heat treatment, weanling rats were fed for 8 wk a diet enriched with 5% isomerized (experimental group) or normal (control group) canola oil. Geometrical isomers of alpha-linolenic acid representing 0.2 g/100 g of the experimental diet were incorporated into liver, platelets, aorta and heart, at the expense of their cis homologue and of 18:2(n-6). The major isomer, 9c,12c,15t-18:3, was also metabolized to 5c,8c,11c,14c,17t-20:5 and to an unknown compound, found in liver, platelets and aorta, which has been identified tentatively as 7c, 10c,13c,16c,19t-22:5. The greater 20:4…
In-vitro and Ex-vivo Inhibition of Blood Platelet Aggregation by Naftazone
1996
Abstract Because of the considerable interest in the role of platelets and antiplatelet therapy in cardiovascular disease, including the aggregation of platelets to each other during arterial thrombosis and atherogenesis, we have studied the effect of naftazone (Etioven), an original vasculotropic drug on platelet aggregation. Rat and human platelets were prepared and incubated in-vitro with different concentrations of naftazone. We found that naftazone inhibited both platelet secretion and aggregation in platelet-rich plasma (PRP) and washed platelets after stimulation with thrombin or ADP. Rats were also treated intraperitoneally for five days with various naftazone doses (0.125-10 mg kg−…
PHOSPHODIESTERASE INHIBITORS PIROXIMONE AND ENOXIMONE INHIBIT PLATELET AGGREGATION IN VIVO AND IN VITRO
1997
The phosphodiesterase type III inhibitors piroximone (PIR) and enoximone (ENO) exert positive inotropic and vasodilating effects in patients with severe heart failure. PIR and ENO raise cyclic AMP levels in cardiac and vascular smooth muscle cells. Platelet activity is also regulated by intracellular levels of cyclic AMP. In this study we have investigated the effects of PIR and ENO on platelet activity in vivo and in vitro. PIR and ENO inhibited ADP induced platelet aggregation in a time- and concentration-dependent manner with IC50-values of 67 +/- 14 mumol/l and 129 +/- 6 mumol/l, respectively. Coincubation of PIR with the adenylate cyclase activator iloprost resulted in a synergistic po…
Influence of traditional Chinese anti-inflammatory medicinal plants on leukocyte and platelet functions.
2003
Abstract The enzymes 5-lipoxygenase and elastase are therapeutic targets in dermatological disorders such as psoriasis. Fifteen extracts from traditional Chinese medicinal plants used to treat topical inflammations were screened for their inhibitory effect on lipoxygenase, cyclooxygenase and elastase activity in intact leukocytes and platelets. Astragalus membranaceus, Forsythia suspensa and Poria cocos inhibited 5-lipoxygenase, with IC50 values of 141, 80 and 141 μg mL−1, respectively. The latter two species, along with Angelica dahurica and Angelica pubescens, also inhibited elastase (IC50 values of 80, 123, 68 and 93 μg mL−1, respectively), while A. pubescens, Atractylodes macrocephala, …
Griffonianone D, an isoflavone with anti-inflammatory activity from the root bark of Millettia griffoniana.
2003
A new isoflavone, griffonianone D (1), and the previously known compounds durmillone and odorantin were isolated from a chloroform extract of the root bark of Millettia griffoniana. The structure of 1 was established as (7E)-(6",7"-dihydroxy-3",7"-dimethyloct-2"-enyl)oxy-4'-methoxyisoflavone on the basis of its spectral data. The chloroform extract of the root bark of M. griffoniana and compound 1 showed anti-inflammatory effects in different experimental models of inflammation.
Enhanced platelet thromboxane synthesis and reduced macrophage-dependent fibrinolytic activity related to oxidative stress in oral contraceptive-trea…
1996
Abstract In previous studies conducted in rats and in women, we have shown that oral contraceptive (OC) administration induced a platelet hyperaggregation simultaneously with an increased platelet lipid biosynthesis which might be related to lipid peroxidation. In the present study, we specifically studied the arachidonic acid and the fibrinolytic pathways in relation to the fatty acid composition in female rats treated for 6 weeks with OC (ethinyl estradiol plus lynestrenol). We found that platelets of treated animals were not only hyper-responsive to thrombin and ADP, but also to sodium arachidonate. In addition, the results of the thrombin-induced release of labeled arachidonic acid pre-…
Folic Acid Deficiency Enhances Oral Contraceptive-Induced Platelet Hyperactivity
1997
Abstract In previous studies conducted in female rats and in women, oral contraceptives (OC) were found to induce a platelet hyperactivity that was related to an oxidative stress. Because cases of megaloblastic anemia have been reported to occur in women taking OC, these treatments are suspected of depleting folate stores. In the study presented herein, which was conducted in rats, we sought to determine the influence of dietary folic acid deficiency (FD) on the thrombogenicity of OC. Animals were fed for 6 weeks with either a folic acid-deficient diet (250 μg/kg folic acid) or a control diet (750 μg/kg). One-half of the animals in each group were treated with OC (ethinyl estradiol plus ly…
Enhancement of immunohistochemical staining
1982
The present paper describes two simple procedures which enhance immunohistochemical staining. One is to cover the sections with a plastic film to keep the serum uniformly distributed and minimize its evaporation. Secondly, rocking of the slides has been introduced, causing the serum to flow back and forth under the plastic film. Using this system, it has been possible to test for the effect of mixing on an immunohistochemical reaction (the demonstration of calcitonin in thyroid C cells). It has been found that mixing definitely enhances the reaction during the first 8 h. No effect of serum volume was observed.
Therapeutic properties of haemodialysis and blood exchange transfusion in organophosphate poisoning
1976
Human blood was contaminated with nitrostigmine, dimethoate and demeton-S-methyl sulfoxide. It was then dialysed, concentrations of organophosphates were determined and dialysance values calculated. The influence of blood exchange transfusion on poison elimination as well as on the cholinesterase activity of blood, brain and muscle was studied in rats poisoned with nitrostigmine. Haemodialysis was found to be quite an effective method for eliminating demeton-S-methyl sulfoxide and dimethoate, dialysance values of 52.98 ml/min and 59.07 ml/min being found for demeton-S-methyl sulfoxide and dimethoate respectively. Nitrostigmine could not be removed by haemodialysis. These findings suggest th…
Amelioration of spinal cord compressive injury by pharmacological preconditioning with erythropoietin and a nonerythropoietic erythropoietin derivati…
2006
Object Spinal cord injury (SCI) is a devastating clinical syndrome for which no truly efficacious therapy has yet been identified. In preclinical studies, erythropoietin (EPO) and its nonerythropoietic derivatives asialoEPO and carbamylated EPO have markedly improved functional outcome when administered after compressive SCI. However, an optimum treatment paradigm is currently unknown. Because the uninjured spinal cord expresses a high density of EPO receptor (EPOR) in the basal state, signaling through these existing receptors in advance of injury (pharmacological preconditioning) might confer neuroprotection and therefore be potentially useful in situations of anticipated damage. Methods…