Search results for "rats"
showing 10 items of 3537 documents
Circadian rhythm in NO synthase I transcript expression and its photoperiodic regulation in the rat pineal gland.
2001
The photoneural regulation of nitric oxide synthase type I (NOS I) expression in the rat pineal was investigated using semiquantitative RT-PCR. NOS I transcript expression exhibited a daily rhythm with peak values during the night hours. The daily rhythm in NOS I transcript expression persisted under constant dark conditions and was abolished under constant light conditions. The extent of nocturnal NOS I expression was found to be dependent on the photoperiod. It was attenuated under 20 h light and 4 h dark (L:D 20:4) compared with 12 h light and 12 h dark (L:D 12:12). The present findings indicate that, in the rat pineal, NOS I transcript expression exhibits a true circadian rhythm. Furthe…
Properties of tuberomammillary histamine neurones and their response to galanin.
1991
Histaminergic neurones in the tuberomammillary nucleus possess electrophysiological properties which distinguish them from other neurones in their neighborhood. Their resting potential is -50 mV and they are spontaneously active at about 2 Hz in a slice preparation. They display a transient outward rectification and an anomalous inward rectification. Bath application of galanin (0.1 microM) reduced their firing rate significantly and hyperpolarized them slightly.
The lipoprotein lipase activity in cultured beating heart cells of the post-natal rat.
1974
Summary The lipoprotein lipase (LPL) activity was studied in cultured beating heart cells of the post natal rat as a function of the culture age, from the freshly trypsinized cell suspension up to the 14th day of culture. The LPL activity remains at a practically stationary level during the first four days of culture, and then increases rapidly to reach a plateau, at a level 3–4 times higher at the 21th day of culturing. The significance of this enzymatic activity progression comparing to 3H thymidine incorporation from the point of view of cell differentiation is discussed. Our results suggest that after the 12th day of culture, cells contain their optimal enzymatic apparatus for lipid met…
Aldosterone biosynthesis induced by ACTH and angiotensin II in newborn rat adrenocortical cells transfected by c-EJ-Ha-ras oncogene
1991
Abstract Adrenocortical cells were obtained by fractionated trypsination of newborn rat adrenal glands and transfected with a plasmid containing the EJ T24 -Ha-ras oncogene. Isolation of adhesive cells led to a proliferative cell line with an overexpression of 21 kDa ras protein. These cells incubated with corticosterone or deoxycorticosterone as the precursor produced a high level of 18-hydroxycorticosterone and aldosterone as identified by gas chromatography- mass spectrometry. ACTH and angiotensin II increased the basal production of aldosterone nineteen-fold and six-fold respectively. Under ACTH stimulation the ratio between aldosterone and 18-hydroxycorticosterone production was 1:3. T…
Transient focal cerebral ischemia significantly alters not only EAATs but also VGLUTs expression in rats: relevance of changes in reactive astroglia
2010
The involvement of plasma membrane glutamate transporters (EAATs - excitatory aminoacid transporters) in the pathophysiology of ischemia has been widely studied, but little is known about the role of vesicular glutamate transporters (VGLUTs) in the ischemic process. We analyzed the expression of VGLUT1-3 in the cortex and caudate-putamen of rats subjected to transient middle cerebral artery occlusion. Western blot and immunohistochemistry revealed an increase of VGLUT1 signal in cortex and caudate-putamen until 3 days of reperfusion followed by a reduction 7 days after the ischemic insult. By contrast, VGLUT2 and 3 were drastically reduced. Confocal microscopy revealed an increase in VGLUT2…
Bone Mineral Density and Bone Metabolism in Diabetes Mellitus
1998
The effect of diabetes mellitus on bone metabolism and bone mineral density is discussed controversially. Diabetes mellitus due to an autoimmune process seems to be associated with low turnover osteopenia either in the animal model or in children and adolescents. A number of factors are discussed as being involved, but in this age group clinical symptoms are missing. Adult patients of either sex with IDDM show a reduced bone mineral density when measured at peripheral sites such as the distal forearm or the femoral neck, diabetic complications such as neuropathy and microangiopathy seem to pronounce the deficit of bone mass. In these patients, osteopenia is accompanied by a high turnover si…
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…
Effect of uric acid in animal models of ischemic stroke: A systematic review and meta-analysis
2020
Addition of uric acid (UA) to thrombolytic therapy, although safe, showed limited efficacy in improving patients’ stroke outcome, despite alleged neuroprotective effects of UA in preclinical research. This systematic review assessed the effects of UA on brain structural and functional outcomes in animal models of ischemic stroke. We searched Medline, Embase and Web of Science to identify 16 and 14 eligible rodent studies for qualitative and quantitative synthesis, respectively. Range of evidence met 10 of a possible 13 STAIR criteria. Median (Q1, Q3) quality score was 7.5 (6, 10) on the CAMARADES 15-item checklist. For each outcome, we used standardised mean difference (SMD) as effect size…
Antiapoptotic effect of calcitonin gene-related peptide on oxidative stress-induced injury in H9c2 cardiomyocytes via the RAMP1/CRLR complex.
2005
Calcitonin gene-related peptide (CGRP) plays an important role in the mediation of protective effects observed in situations such as ischemic preconditioning in rat hearts. In this study, we investigated in H9c2 rat cardiomyoblasts if the protective effect of CGRP could be linked to an inhibitory effect on the apoptotic pathway. We also determined the specificity of observed effects by treatment with adrenomedullin (ADM) in stress conditions generated by 100 microM hydrogen peroxide. Using MTT assays, we demonstrate that a pretreatment with CGRP decreases by half the loss of cell viability induced by H(2)O(2). CGRP inhibits phosphatidylserine externalization, caspase 3 activation and DNA fr…