17 hydroxysteroides urinaires

DETAILED DESCRIPTION Example -methyl-3,5-androstadiene-3, l7fi-diol 3,17-diacetate (II) A solution of 10 g. of the known compound 7a-methyl- 17B-hydroxy-4-androsten-3-one (I), 1 g. of paratoluenesulfonic acid and 100 ml. of acetic anhydride in 400 ml. of toluene was refluxed under nitrogen for about 5 hours. The solution was washed with water containing a small amount of pyridine, then several times with water, dried over magnesium sulfate, filtered and the solvent removed to yield crystalline 7u-methyl-3,l7fi-dihydroxy-3,5-androstadiene 3,17-diacetate (II). The product was dried thoruoghly under high vacuum to remove the last traces of acetic anhydride.

Neurosteroids are synthetized in the central and the peripheral nervous system, in glial cells, and also in neurons, from cholesterol or sieroidal precursors imported from peripheral sources. They include 3β-hydroxy-Δ 5 -compounds, such as pregnenolone (PREG) and dehydroepiandrosterone, their sulfate esters, and compounds known as reduced metabolites of steroid hormones, such as the tetrahydroderivative of progesterone 3α-hydroxy-5α-pregnan-20-one. These neurosteroids can act as modulators of neurotransmitter receptors, such as GABA A , NMDA, and sigma 1 receptors. Progesterone itself is also a neurosteroid, and a progesterone receptor has been detected in peripheral and central glial cells. At different sites in the brain, neurosteroid concentrations vary according to environmental and behavioral circumstances, such as stress, sex recognition, or aggressiveness. A physiological function of neurosteroids in the central nervous system is strongly suggested by the role of hippocampal PREGS with respect to memory performance, observed in aging rats. In the peripheral nervous system, a role for PROG synthesized in Schwann cells has been demonstrated in remyelination after cryolesion of the sciatic nerve in vivo and in cultures of dorsal root ganglia. A new mechanism of PREG action discovered in the brain involves specific steroid binding to microtubule associated protein and increased tubulin polymerization for assembling microtubules. It may be important to study the effects of abnormal neurosteroid concentration/metabolism in view of the possible treatment of functional and trophic disturbances of the nervous system.

17 hydroxysteroides urinaires

17 hydroxysteroides urinaires

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17 hydroxysteroides urinaires

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