J Grandjean

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Arterial tissue has been analysed by 31P-, 13C-, 23Na- and 1H-NMR spectroscopy. Rabbit thoracic aortas were mounted on a system with perfusate circulation and studied in basal conditions. Phosphorus spectra remained stable for hours and showed low levels of phosphocreatine (PCr) compared to skeletal, cardiac or even to nonvascular smooth muscle. Significant(More)
Transport of Pr3+ across phosphatidyl choline vesicles, as monitored by 31P nmr, is second-order in the crown ether carboxylic acid 2, as it is with respect to lasalocid (X-537 A). When the synthetic (2) and the natural (lasalocid) ionophores are incorporated together in approximately 3:1 ratio into the lipidic phase, the transport velocity is markedly(More)
Na+ and K+ fluxes mediated by lasalocid A across erythrocyte membranes have been determined from 23Na-NMR peak areas and chemical shifts, respectively. In similar experiments, Cl- transport has been monitored by NMR signal intensities. Taking into account the external pH variations, the results are readily explainable in terms of charge-balance(More)
The structure and dynamics at the interface of swelling clays (smectites) are crucial to such diverse applications as drilling for oil, cosmetics, paints, water treatment, or chemical reactions. From our previous NMR studies on clay suspensions, we have shown how the orientation of interfacial molecules is affected by the clay structure1, by the nature of(More)
The relaxation rate enhancements of the 23Na nuclei for NaHCO3 solutions of calmodulin and its tryptic peptides TR-1 and TR-2 indicate true binding of Na+ ions to these biomolecules. With both TR-1 and TR-2, Na+ binding occurs in competition with Ca2+ and Mg2+ binding: log KNa approximately equal to 2, log KMg apoproximately equal to 4, log KCa(More)