Rhône-Poulenc

About: Rhône-Poulenc is a based out in . It is known for research contribution in the topics: Alkyl & Catalysis. The organization has 8909 authors who have published 8934 publications receiving 182241 citations. The organization is also known as: Rhone-Poulenc.

Clinical profile of nicorandil: an overview of its hemodynamic properties and therapeutic efficacy.

Abstract: Nicorandil is a new vasodilator agent. Efficacy and safety of nicorandil in the treatment of angina pectoris have been evaluated through an extensive clinical program with a total of 1,680 patients who received the product. Results of hemodynamic studies provide clear evidence of the vasodilatory effect of nicorandil. In a population of patients with normal left ventricular function, a reduction in preload was apparent from a decrease in left ventricular end-diastolic pressure from 7.4 +/- 1.7 to -3.2 +/- 1.5 mm Hg. Furthermore, nicorandil produced marked reductions in total peripheral resistance (19%) and aortic blood pressures with decreases in systolic pressure of 34% and in diastolic pressure of 21%. At antianginal doses, nicorandil has a coronary vasodilating effect as well as a balanced peripheral action that leads to decreases in both preload and afterload. Therefore, nicorandil affects two of the main hemodynamic determinants of oxygen demand without impairing myocardial contractility or atrioventricular conduction. In addition, its strong spasmolytic activity is of particular interest when dynamic coronary obstruction is considered. Nicorandil clearly has demonstrated K(+)-channel-opening activity. In addition, the range of plasma concentrations in humans at therapeutic doses is similar to that of experimental models in which the K(+)-channel activity has been determined. This mechanism of action may explain the different hemodynamic profiles of nicorandil and nitrates in humans. Nicorandil is an effective and potent antianginal agent at a dose of 10-40 mg, which in monotherapy controls 69-80% of patients with stable chronic angina. Comparative trials have shown that the efficacy of nicorandil compares with that of drugs from the main classes of antianginal drugs--beta-blockers (atenolol, propranolol) and a Ca2+ antagonist (diltiazem). Patients treated for as long as 3 months or 1 year have shown sustained efficacy with no evidence of development of tolerance to the drug. The long duration of action allows effective treatment with a well-tolerated b.i.d. regimen. At the recommended doses, the main side effects were limited to headaches. They usually occurred early in the course of treatment and can be diminished by a progressive titration. From the large safety data base, there is no evidence that nicorandil induced exacerbation of myocardial ischemia or abrupt withdrawal syndrome. Nicorandil does not adversely affect the lipid profile or the glucose level. As an antianginal drug with a novel mechanism of action, nicorandil provides a useful alternative to existing antianginal agents in the long-term management of patients with angina pectoris.

Neurotensin effects on evoked release of dopamine in slices from striatum, nucleus accumbens and prefrontal cortex in rat.

Abstract: The effects of neurotensin (NT) on the K+-evoked release of endogenous and tritiated dopamine in striatum and on 3H-dopamine in slices from nucleus accumbens and prefrontal cortex were investigated. In striatum, NT (1–1000 nM) elicited a dose-dependent increase in endogenous and 3H-dopamine release. The dose-response curves were comparable with the two methods. Concerning the comparison of NT modulation of 3H-dopamine release in the three cerebral structures, the peptide induced a more marked effect in striatum with a maximal effect of 150% increase. In accumbens, NT (1–1000 nM) potentiated the K+-evoked 3H-dopamine release, but in contrast with striatum, the plateau corresponded to a 50% increase. In prefrontal cortex, NT (1–1000 nM) induced small but significant effects, with a maximal increase of 50% at 100 nM. Acetyl-NT (8–13) displayed an action similar to the natural peptide while NT (1–8) did not exhibit any effect, suggesting that the action of NT involved a receptor. The presence of tetrodotoxin did not alter the facilitating effects of NT in the three structures, indicating that interneurons were not involved in the action of NT. The comparison of the effects of NT showed that in terms of efficacy, NT induced an increase in dopamine release more marked in striatum than in nucleus accumbens and prefrontal cortex. These results are consistent with differences in NT receptors localization in these three dopaminergic structures.

The solubilization of the basic subunit of sugarbeet seed 11-S globulin during priming and early germination

Abstract: The basic B-subunit of the seed storage protein 11-Sglobulin (an 11-S-legumin type protein) is the majorpolypeptide in soluble protein extracts from primedsugarbeet {Beta vulgaris L.) seeds. In contrast, only asmall amount of this protein is present in correspondingextracts from untreated dry mature seeds. Here, and asfor all 11-S globulins describe B-chaid so far isn, thelinked to other polypeptide(s), corresponding mostpresumably to an acidic A-chain, through the formationof disulphide bridge(s). Polyacrylamide gel electrophoreticanalyses of total and soluble protein extracts fromuntreated and primed seeds strongly indicate that thispriming-induced solubilizatio B-chain of resulte thne dfrom an endoproteolytic attack on the A-chain.Microscopical immunolocalization showed a uniformdistribution of the 11-S globuli B-chain oven r the proteinbodies of the embryonic cells from the untreated seeds.For the primed seeds, however, the B-subunit of 11-Sglobulin diffused out of the protein bodies and invadedthe cytosolic compartment. This phenomenon occurredindependently of the manner of priming, being observedwith hydroprimed and osmoprimed seeds, as well as withsugarbeet seeds that had been primed by a prehydrationtreatment. Quantitative analyses of the amounts ofsoluble 11-S globuli B-chain havn e enabled the primingof sugarbeet seeds to be optimized.Keywords: germination, 11-S globulin mobilization,immunocytochemistry, seed priming, storage proteins,sugarbeet.CorrespondenceAbbreviations: DTT = dithiothreitol; PAGE = polyacrylamidegel electrophoresis; PEG = polyethylene glycol; SDS =sodium dodecyl sulphate.