ABSTRACT
But : Le but de cette etude a ete de determiner la ou les doses de Methylprednisolone qui induit une immunodepression reversible dans un temps long sans perturber les marqueurs du foie; des reins et du metabolisme phosphocalcique chez le lapin sain. Materiel et methodes : Cette etude a ete effectuee chez quinze lapins. Ils ont constitue cinq lots selon l'administration de Nacl et du Methylpredmisolone. Lot control (Nacl 0; 9); Lot I (2;5mg/kg MP); Lot II (5mg/kg MP); Lot III (10mg/kg MP) et Lot IV (15 mg/kg MP). Les marqueurs biochimiques ont ete doses par des methodes chimique et enzymatique. Resultats : Les resultats ont montre une immunodepression pendant 7 jours avec les doses de 10 et 15 mg/kg de MP (P0;05). Les perturbations biochimiques ont ete observees avec 15 mg/kg ou le calcium a ete abaisse a J15 et la TGO augmentee a J3 par rapport a J0 (P0;05). Conclusion : Cette etude a montre que les doses qui induisent une longue immunodepression (7 jours) sont 10 et 15 mg/kg de MP. Elle suggere que la dose qui ne perturbe pas les parametres biochimiques induisant une immunodepression longue reversible est 10 mg /kg de MP
Subject(s)
Immunosuppression Therapy , Metabolism , Methylprednisolone , RabbitsABSTRACT
Purpose: The asexual proliferation of Plasmodium; inside the erythrocyte; is accompanied by the synthesis of huge quantities of phosphatidylcholine (PtdCho) and phospha- tidylethanolamine (PtdEtn). These needful phospholipids for the cytoplasmic membrane of the merozoites are provided by the precursors choline and ethanolamine. PtdCho and PtdEtn are synthesized by the parasite because the erythrocyte is unable to do it. In order to assess the dynamism of the phospholipid pathways; we aimed to inves- tigate the respective shape of the uptake of choline and ethanolamine by Plasmodium falciparum. Method: Time-course experiments and kinetic assays were performed respectively with fixed and ranged concentrations of radioactively-labelled choline and ethanolamine. The labelled-precursors were added in the culture of P. falciparum infected-erythrocytes and the incorporated molecules in phospholipids were measured with a scintigraph counter. Result: The results showed that the incorpo- ration of precursors in the infected-erythrocyte occurred with a Michaelis-Menten's kinetic shape. According to the maximum rate (Vmax); the pathway of ethanolamine incorpo- ration was faster than that of choline. Similarly; affinity for ethanolamine was greater than that of choline. Conclusion: Although PtdCho is the major phospholipid in the membrane; this study rules out that the influx of ethanolamine in the infected-erythrocyte; in vivo conditions; is more dynamic than choline