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Biomedical subjects

A Garnier

Publications and source records attributed to A Garnier.

60 records · Page 4Linked to original sources
PubMedDate not supplied

Modulation of fatty acid-binding protein content of adult rat heart in response to chronic changes in plasma lipid levels.

The aim of this work was to study in the adult rat heart the effect of modifications of fatty acid (FA) supply on the content of cytoplasmic fatty acid-binding protein (H-FABPc). To modify the amount of circulating lipids, three different treatments were chosen: (i) an hypolipidemic treatment with Clofibrate, administered daily through a gastric tube at a dose of 250 mg/kg per day for one week, (ii) a continuous intravenous infusion of 20% Intralipid, a fat emulsion, for one week at a dose of 96 ml/kg per day, and (iii) a normobaric hypoxia exposure (pO2 = 10%) for three weeks. At the end of each treatment plasma lipids, myocardial H-FABPc content and the activities of three key enzymes (citrate synthase, CS, fructose-6-phosphate kinase, FPK and hydroxy-acyl CoA-dehydrogenase, HAD) were assessed. With each of the three treatments a decrease of plasma cholesterol and phospholipid levels was observed. Plasma FA concentration increased with Intralipid infusion and decreased with chronic hypoxia. The heart H-FABPc content was increased by 20% with Clofibrate, decreased by 20% with chronic hypoxia and remained unaltered upon Intralipid treatment. The induced changes in H-FABPc content were not related directly to changes in plasma lipid levels. CS activity was slightly decreased in the hypoxia group, FPK activity decreased in the Clofibrate group, and HAD activity decreased in the Intralipid group. Among the various groups heart H-FABPc content was related to HAD activity. In conclusion, the H-FABPc content of adult rat heart appears responsive to changes in plasma lipid levels.

Animals↗
PubMedDate not supplied

Study of adenovirus production in serum-free 293SF suspension culture by GFP-expression monitoring.

The red-shifted S65T mutant green fluorescent protein (GFP) was used to compare the adenovirus (Ad) production and post-infection survival of 293SF and 293S cells in serum-free and serum-containing flask cultures, respectively. The GFP-expressing vector permitted the quantification of both the level of GFP expressed by infected cells and the infectious viral content of the cultures by flow cytometry in a simple, fast, sensitive, and reliable way. The GFP has the main advantage of fluorescing without any substrate addition. Infected cultures showed the coexistence of two populations of fluorescent cells, high-fluorescence cells (HFCs) and low-flourescence cells (LFCs), in proportions that varied between 20 and 75 hpi. The gradual increase in the number of LFCs at the expense of HFCs correlated well with the increase in the number of dead cells. This relationship could be used for the continuous measure of a culture's viability with the appropriate on-line instrumentation. The post-infection death rate of infected 293SF cells was higher than that of infected 293S cells, but the level of GFP fluorescence in viable, highly fluorescent cells was similar in the two infected cell lines. The number of infectious viral particles (IVPs) was quantified in less than 24 h by an infection assay of 293S cells in wells with viral particles extracted from the culture samples, and the results were more reproducible (+/- 10% variation) than those generally reported for conventional plaque assay titrations or end-point dilutions. The viable cell-specific IVP concentrations were for most experiments similar, indicating again that the difference between the two cell lines was their unequal post-infection viabilities, not the virus production by the infected living cells.

Adenoviridae↗
PubMedDate not supplied

New approaches towards fluorescence labelling of messenger RNA transcripts.

Fluorescence labelling of nucleic acids is being used for a wide range of biological applications. The performance of these techniques is dependent on fluorochrome labels with a high sensitivity and high resistance to photobleaching. Indo-cyanine dyes such as Cy3, Cy5 or Cy7 have been found to fulfill these requirements. This study describes several different RNA labelling techniques allowing for a Cy5 based detection of mRNA transcripts.

Carbocyanines↗
PubMedDate not supplied

An experimental model of hypoxia on isolated rat heart in recirculating system: study of fatty acid metabolism with an iodinated fatty acid.

An experimental model of hypoxia was developed on isolated rat heart to study the effects of hypoxia on cardiac performance and metabolism. Fatty acid (FA) metabolism was explored by external detection with a labelled FA, iodohexadecenoic acid (IHA). Hearts, after 30 min preperfusion in an open system, were transferred in a recirculating system for 40 min and perfused with oleate, glucose, lactate, pyruvate and IHA, either in normoxia (pO2 = 660 mmHg) or in hypoxia (pO2 = 220 mmHg). After 40 min hypoxic recirculation, oxygen uptake and dynamic parameters, except the heart rate, decreased respectively by 56% and 44%, and remained constant throughout the perfusion. Glucose utilization increased 2 fold, endogenous glycogen fell by 50% and lactate + pyruvate production increased 3 fold, showing a stimulation of glycolysis. Oleate uptake decreased by 28%, while triglycerides content remained higher. The ATP/ADP ratio decreased by 24%. Conversely to oleate, IHA uptake was not significantly modified, but its intracellular fate showed a higher radioactivity in all lipid fractions: polar lipids, diglycerides, free FAs and triglycerides. beta oxidation of IHA, evidenced by iodide production, decreased by 39%. The external detection of cardiac radioactivity allowed us to obtain time-activity curves that were analyzed with a 4-compartment mathematical model. The data evidenced an esterification ratio significantly higher in hypoxia. The metabolism of IHA as estimated by the intracellular analysis or, in a non-invasive way, by external detection, was similar to the metabolism of oleate. Thus, lipid metabolism, in hypoxia, can be explored by external detection with IHA.

Animals↗
PubMedDate not supplied

[The cardiovascular steroid system].

In this review, the authors describe: (1) the different types of glucocorticoid hormone receptors, on the cell membrane and two types inside the cell, the MR and GR (mineralo- and glucoreceptors); (2) the synthesis of the hormones with the decisive role of the final enzymes, 11 beta-hydroxylase and aldosterone-synthetase; (3) the increasing evidence for a cardiovascular steroid system in the vessels as well as in the myocardium. The authors have reported new data suggesting the existence of an endocrine cardiac steroidogenic system in the heart with a potential physiological and pathological relevance (for transmembrane ion transport and trophic alterations).

Adrenal Cortex Hormones↗