Search results for "Rabbit."
showing 10 items of 552 documents
Role of C-reactive protein in atherogenesis: can the apolipoprotein E knockout mouse provide the answer?
2005
Objective—Human C-reactive protein (CRP) was reported to accelerate atherosclerotic lesion development in male but not in female apolipoprotein E (apoE) knockout mice. Here, mice expressing rabbit CRP (rbCRP) were crossbred onto apoE knockout animals, and the effect on atherogenesis was studied.Methods and Results—Hemolytic complement activity could not be detected in apoE knockout mice. Furthermore, in contrast to human complement, neither rabbit nor human CRP complexed to modified low-density lipoprotein–activated murine complement. At 52 weeks, rbCRP levels were similar in male and female transgenic animals. Serum cholesterol levels were equivalent in female animals irrespective of rbCRP…
Overexpression of human hepatic lipase and ApoE in transgenic rabbits attenuates response to dietary cholesterol and alters lipoprotein subclass dist…
1999
Abstract —The effect of the expression of human hepatic lipase (HL) or human apoE on plasma lipoproteins in transgenic rabbits in response to dietary cholesterol was compared with the response of nontransgenic control rabbits. Supplementation of a chow diet with 0.3% cholesterol and 3.0% soybean oil for 10 weeks resulted in markedly increased levels of plasma cholesterol and VLDL and IDL in control rabbits as expected. Expression of either HL or apoE reduced plasma cholesterol response by 75% and 60%, respectively. The HL transgenic rabbits had substantial reductions in medium and small VLDL and IDL fractions but not in larger VLDL. LDL levels were also reduced, with a shift from larger, m…
Toxicity of the antimalarial artemisinin and its dervatives.
2010
As long as no effective malaria vaccine is available, chemotherapy belongs to the most important weapons fighting malaria. One of the most promising new drug developments is the sesquiterpene artemisinin (ARS) and its derivatives, e.g., artemether, arteether, and sodium artesunate. Large clinical studies and meta-analyses did not show serious side effects, although proper monitoring of adverse effects in developing countries might not be a trivial task. There is a paucity of large-scale clinical trials suitable to detect rare but significant toxicity. Therefore, a final and definitive statement on the safety of artemisinins still cannot be made. In contrast, animal experiments show consider…
Immunopathogenesis of atherosclerosis: endotoxin accelerates atherosclerosis in rabbits on hypercholesterolemic diet.
2001
Background—On the basis of our concept that atherosclerosis has an immunopathological background, we tested whether activation of the innate immune system influences its progression.Methods and Results—Hypercholesterolemic (0.5% wt/wt diet) rabbits received either repeated intravenous injections of endotoxin (Escherichia colilipopolysaccharide 1.25 to 2.5 μg, once per week) or a self-limiting cutaneousStaphylococcus aureusinfection with or without a quinolone antibiotic. Measured laboratory parameters, including LDL and HDL cholesterols, were similar in the different groups of hypercholesterolemic animals. All endotoxin-treated animals developed transient episodes of fever after endotoxin a…
Autoinhibition of nicotinic release of noradrenaline from postganglionic sympathetic nerves
1970
1. The effects of nicotine, DMPP (1,1-dimethylphenylpiperazine) and acetylcholine (plus atropine) on the isolated rabbit heart were investigated. Heart rate, amplitude of contraction, coronary flow and output of noradrenaline into the perfusate were recorded. Noradrenaline was estimated fluorimetrically. 2. All nicotinic drugs evoked a dose-dependent output of noradrenaline and increased the rate and the amplitude of contraction. Increases of heart rate in response to nicotine and DMPP and increases of amplitude of contraction in response to all nicotinic drugs were clearly related to the output of noradrenaline. 3. The dose-response curves of the noradrenaline output evoked by nicotine, DM…
Muscarinic inhibition of [3H]-noradrenaline release on rabbit iris in vitro: effects of stimulation conditions on intrinsic activity of methacholine …
1988
1. Rabbit isolated irides were loaded with [3H]-noradrenaline and superfused with Tyrode solution. The inhibition by the muscarinic agonists (+/-)-methacholine and pilocarpine of the [3H]-noradrenaline overflow into the superfusate evoked by field stimulation (pulses of 1 ms duration, 75 mA) was measured as an index of activation of presynaptic muscarinic receptors. 2. The fractional rate of release per pulse during the first stimulation period (S1) was low with 360 pulses at 3 Hz, intermediate with 360 pulses at 10 Hz and high with 1200 pulses at 10 Hz. Upon repetitive stimulation (7 periods at 20 min intervals), the fractional rates of release per pulse during S7 no longer differed, sugge…
Muscarinic inhibition of potassium-induced noradrenaline release and its dependence on the calcium concentration.
1975
1. Noradrenaline release from the isolated rabbit heart was evoked by perfusion with a medium containing 135 mM potassium and 17 mM sodium ions (high K+-low Na+). 2. The noradrenaline output in response to high K+-low Na+ was dose-dependently decreased by methacholine (0.625-320 muM) and this effect was reserved by atropine 1.44 mM. 3. Lowering the calcium concentration of high K+-low Na+ from 1.8-0.1125 mM decreased the noradrenaline output by 85%. The effect of methacholine, expressed as % inhibition of noradrenaline release, was potentiated by lowering of the calcium concentration. 4. Both at normal and lowered calcium concentrations the inhibitory action of methacholine was larger from …
Effects of several muscarinic agonists on cardiac performance and the release of noradrenaline from sympathetic nerves of the perfused rabbit heart
1972
Summary 1 The effects of several muscarinic agonists on atrial tension development, ventricular rate and noradrenaline release from terminal sympathetic fibres evoked by electrical nerve stimulation (SNS) and 1,1-dimethyl-4-phenylpiperazinium (DMPP) were measured in isolated perfused rabbit hearts. 2 Hexamethonium, in a concentration which almost abolished the release of noradrenaline by DMPP, had no effect on the release produced by SNS, confirming that the stimulation was postganglionic. 3 The order of potency for inhibition of atrial tension development was N-methyl-1,2,5,6, tetrahydro-nicotinic acid prop-2-yne ester (MH-1)>oxotremorine > acetylcholine > methacholine > carbachol > furtre…
Storage and release of false transmitters after infusion of (+)- and (?)-?-methyldopamine
1971
Rabbits were given an infusion of 10 mg/kg (−)- or 30 mg/kg (+)-α-methyldopamine and killed after 135 min. The noradrenaline content of the heart was decreased to 26±5 and 34±2%, respectively, of the control value. After infusion of the (+)-isomer the missing noradrenaline was replaced by (−)-α-methylnoradrenaline. Electrical stimulation of the sympathetic nerves or infusion of acetylcholine plus atropine caused an output of noradrenaline and (−)-α-methylnoradrenaline from the isolated heart. The two amines were released in the same proportion as they were stored in the heart and the total output of both amines equalled the output of noradrenaline from control hearts. Nerve stimulation caus…
Short- and long-latency muscarinic inhibition of noradrenaline release from rabbit atria induced by vagal stimulation.
1988
1. The influence of the time interval between vagal and sympathetic nerve stimuli on the magnitude of muscarinic inhibition of noradrenaline release was studied in the isolated perfused rabbit atria preparation. The transmitter stores were labelled with [14C]choline and [3H]noradrenaline. 2. The right cardiac postganglionic sympathetic nerves were stimulated at 3 Hz for 3 min three times at intervals of 10 min. The [3H]noradrenaline outflow evoked by the second stimulation equalled the averaged means of the log values of amine outflows evoked by the first and third stimulations. 3. During the second sympathetic stimulation the right vagus nerve was stimulated (3 Hz, 3 min) in such a way tha…