Search results for "STAR"
showing 10 items of 4285 documents
The Activation Pattern of the Antioxidant Enzymes in the Right Ventricle of Rat in Response to Pressure Overload is of Heart Failure Type
2003
In the left ventricle subjected to pressure overload activity, the antioxidant enzymes increased at the hyperfunctional stage. During the transition to heart failure, these enzymes are down-regulated, oxidative stress increases, and apoptosis progresses. Maladaptative activation of the antioxidant enzymes at an early stage may contribute to the intrinsic vulnerability of right ventricle to pressure overload. The authors studied changes in expression and activity of the enzymes manganese and copper-zinc superoxide dismutases, glutathione peroxidase, and catalase in the right ventricle of rat following induction of pulmonary hypertension by injection of monocrotaline. Increase in the manganes…
Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.
1993
Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…
Prenatal Brain Damage in Preeclamptic Animal Model Induced by Gestational Nitric Oxide Synthase Inhibition
2010
Cerebral palsy is a major neonatal handicap with unknown aetiology. There is evidence that prenatal brain injury is the leading cause of CP. Severe placental pathology accounts for a high percentage of cases. Several factors predispose to prenatal brain damage but when and how they act is unclear. The aim of this paper was to determine if hypoxia during pregnancy leads to damage in fetal brain and to evaluate the localization of this injury. An animal model of chronic hypoxia produced by chronic administration of a nitric oxide synthase inhibitor (L-NAME) was used to evaluate apoptotic activity in fetal brains and to localize the most sensitive areas. L-NAME reproduces a preeclamptic-like c…
Radiodensitometric study for evaluation of bone mineral density around dental implants after zoledronic acid treatment in ovariectomized rats
2017
Background The purpose of this study was to evaluate the effects of intravenous zoledronic acid applied systemically on osseointegration of dental implants and the surrounding bone mineral density (BMD) in the ovariectomized rats. Material and Methods 36 rats were divided into three groups: control (CTRL), ovariectomy (OVX), and ovariectomy-zoledronic acid (OVX/ZOL). The rats in the CTRL group underwent sham surgery, while rats in OVX and OVX / ZOL group underwent ovariectomy. After 12 weeks, rats from OVX / ZOL were injected with 0.04 mg/kg ZOL intravenously once a week for 6 weeks. The rats from CTRL and OVX groups were injected with 0.9% NaCl. Implants were placed in the left tibia. Afte…
Composition en acides gras des hémisphères cérébraux de rats spontanément hypertendus allaités par des femelles Wistar
2003
Total lipid fatty acid composition was investigated in brain hemispheres of male Spontaneously Hypertensive Rats (SHR), compared with normotensive Wistar Kyoto rats (WKY) used as controls. Both strains were suckled by adoptive Wistar mothers, and then fed a standard diet after weaning. No difference was observed between the two hemispheres of WKY killed either at 10 or 30 days. In SHR killed at 10 days, the two hemispheres showed differences, SHR left hemispheres exhibiting greater fatty acid composition changes than those of WKY, phenomenon that toned down at 30 days. Hence, SHR pups showed a different total lipid fatty acid composition of their brain hemispheres when compared with their W…
Cisplatin-induced peripheral neuropathy: neuroprotection by erythropoietin without affecting tumour growth
2007
This study examined the dose-dependent efficacy of erythropoietin (EPO) for preventing and/or treating cisplatin (CDDP) induced peripheral neurotoxicity (CINP), and its influence on tumour treatment and growth. Rats received eight intraperitoneal (ip) injections of 2 mg/kg CDDP twice weekly. EPO co-administered (50 or 10 microg/kg ip, three times/week) had a dose-dependent effect, partially preventing CINP, but 0.5 microg/kg ip was not effective. The neuroprotective effect lasted at least 5 weeks after the last dose of EPO and CDDP. In addition, EPO (50 microg/kg ip three times/week) after the last injection of CDDP still induced a significant recovery of CINP. In a separate experiment in r…
Antagonism by SR 48692 of mechanical responses to neurotensin in rat intestine.
1996
Abstract 1. The effects of SR 48692 on neurotensin (NT)-induced mechanical responses were investigated in rat duodenum and proximal colon by use of isometric, isovolumic preparations. 2. SR 48692 inhibited the relaxant responses to NT in duodenal circular and longitudinal muscle. It also antagonized the NT-induced contractile effects in duodenal circular muscle and in proximal colon (both muscular layers). 3. From Schild analysis and pA2 value for SR 48692 was 8.2 in tissues where NT induced relaxant effects and 7.5 in tissues where NT induced contractile effects and the slope of the regression line was not significantly different from unity, indicating competitive antagonism. 4. SR 48692 d…
Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells
2007
The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H(1) and …
Assessment of the cardiostimulant action of propionyl-L-carnitine on chronically volume-overloaded rat hearts.
1993
Chronic volume overload was induced in young rats of Wistar strain by surgical opening of the aorto-caval fistula. Three months later, during in vitro perfusion with exogenous palmitate, left ventricular function and energy turnover (QO2) of hypertrophied hearts were severely depressed. This seemed to be related to impaired long-chain fatty acid utilization, as reflected by decreased 14CO2 production from U-14C-palmitate and decreased tissue levels of L-carnitine. Another group of rats exposed to chronic volume overload was pretreated for 2 weeks before sacrifice with propionyl-L-carnitine (250 mg/kg/day), and the hearts were perfused with 1.2 mM palmitate and 10 mM propionyl-L-carnitine. I…
Intermittent ethanol exposure induces inflammatory brain damage and causes long-term behavioural alterations in adolescent rats
2007
Adolescent brain development seems to be important for the maturation of brain structures and behaviour. Intermittent binge ethanol drinking is common among adolescents, and this type of drinking can induce brain damage. Because we have demonstrated that chronic ethanol treatment induces inflammatory processes in the brain, we investigate whether intermittent ethanol intoxication enhances cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in adolescent rats, and whether these mediators induce brain damage and cause permanent cognitive dysfunctions. Adolescent rats were exposed to ethanol (3.0 g/kg) for two consecutive days at 48-h intervals over 14 days. Levels of COX-2, iN…