[Commemoration of the 100th anniversary of the birth of Dean Leon Binet (1891-1971)].
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Biomedical subjects
Publications and source records attributed to J F Cier.
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In this report we have tried to determine whether or not catecholamines are involved in the progressive muscular dystrophy. Catecholamines and their metabolites were studied in urines of children with Duchenne disease or other forms of myopathy (limb-girdle and facio-scapulo humeral myopathies). Catecholamine deaminated metabolites were normal in either form of myopathy; in contrast, Duchenne patients, contrarily to other children, eliminated excessive amounts of most amines (catecholamines and methoxylated amines) in relation to age and degree of disease evolution. Our results indicate that catecholamines are not the primary factors involved in the pathogenesis of Duchenne myopathy, but are rather secondary to some disease effects. It is suggested that the high excretion of catecholamines and their methoxylated amine metabolites observed in severely affected Duchenne boys might be related to thermoregulatory process or/and to alterations in some enzymatic systems.
Studying the effects, on the isolated rat duodenum motricity, of ten compounds precursors or metabolites of catecholamines, the following results were obtained: The direct metabolites of epinephrine and norepinephrine (metanephrine, normetanephrine), are either ineffective at concentrations below 5 X 10(-6) M, or weakly inhibitory at higher concentrations. Such inhibitory effects are prevented by alpha- and beta-blockers. 3-methoxy, 4-hydroxyphenylglycol and vanylmandelic acid have no significant effect. The catecholamine precursor, dopamine, the related compounds DOPA, 3 methoxytyramine, and to a lesser extent, 3-O methyl DOPA and homovanillic acid, have excito-motor effects at concentrations ranging mainly from 10(-7) M to 10(-5) M. At higher concentrations, the same compounds frequently exhibit inhibitory effects. The excito-motor effects might be due to a serotoninergic mechanism, since they are suppressed by the serotoninergic blocking agents methysergide and cyproheptadine. Furthermore, in the case of DOPA, we were able to establish a relationship between the excito-motor effects and duodenal serotonin stores. As for the inhibitory effects, they may be prevented by using alpha and beta blocking agents. Dihydroxyphenylacetic acid has no effect on the isolated rat duodenum motricity. The fact that dopamine and related compounds may have excitomotor effects at some concentrations, correlated with some physiopathological observations in man and animal allows some considerations about the eventual role of dopamine on intestinal motricity.
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We have studied the responsibility of tissue serotonin reserves in the excito-motor effects induced by DOPA and dopamine on the isolated rat duodenum in vitro in certain experimental conditions. Two groups of experiments have been performed: first the determination of serotonin endogenous stores after administration of repeated high doses of DOPA and dopamine in the organ bath, secondly the evaluation of motor effects of DOPA and dopamine on rat duodenums experimentally depleted of their endogenous serotonin stores. Serotonin levels were lowered after DOPA and the excito-motor effect of this compound was suppressed in serotonin-depleted duodenums. After dopamine, serotonin tissue levels were not significantly lowered, and the excito-motor effect was observed whatever the serotonin stores may be, depleted or not. Our results are consistent with a relationship between the excito-motor effects of DOPA and serotonin release from endogenous stores; but, concerning dopamine, experimental proofs supporting this hypothesis have not been obtained.
The motor effects of DOPA and Dopamine on the isolated rat duodenum in vitro have been studied by establishing successive dose- response curves. These effects are either excitatory or inhibitory according to the concentrations used. In every case they are of small amplitude. The inhibitory effects do not exist in the presence of alpha, and beta blocking agents. The excitatory effects are suppressed by using a serotoninergic blocking agent.
The study of the direct action of dopamine on the rat duodenum serotoninergic receptors and the parallelism of the results obtained with the motricity curves of this organ in vitro allows us to conclude that dopamine recognizes serotoninergic receptors : the excito- motor effect observed with certain dopamine concentrations on the isolated rat duodenum may be attributed to this action of dopamine on serotoninergic receptors. These results seem in agreement with the observations of other authors.
A culture obtained from rat duodenal smooth muscle layer is described. The cells were isolated by trypsinization (0.2%), and the medium used for culture was either MEM with glutamine and non-essential AA or RPMI, both containing 10% foetal calf serum. The cell culture contained both smooth muscle cells and fibroplasts in proportions varying with the age of the culture. At day 6, cell differentiation is important. At day 12, when the cells are confluent, the majority of the cells are fibroblasts. Although it is difficult, the transfer of cells is possible at least twice.
A culture obtained from rat duodenal smooth muscle layer is described. The cells are isolated by trypsinization (0.2 %) and the medium used for culture is either MEM with glutamine and non essentiel AA, or RPMI, both containing 10 % foetal calf serum. The cell culture contains both smooth muscle cells and fibroblasts in proportions varying with the age of the culture. At day 6, cell differenciation is important. At day 12, when the cells and confluent, the majority of the cells are fibroblasts. Although it is difficult, the transfer of cells is possible at least twice.
Immunoassayable Plasma renin activity (PRA) was measured in normal subjects aged from 15 days to 15 years. A very progressive decrease of PRA with age could be demonstrated. Practical conditions for the study of PRA were defined.