Mechanisms of physiological and pharmacological sex hormone action on the XXXX liver.

@entity1 @entity3429 @entity11796 @entity2931 @entity31426 @entity14128 @entity7828 @entity2692 @entity134 @entity342 @entity8472 @entity35
@entity342 and @entity2931 receptors have been demonstrated in @entity1 liver, but since it is generally accepted that they are probably non-functional at endogenous @entity134 concentrations, it is not apparent how they mediate physiological influences on this organ. Nor is it certain to what extent pharmacological actions of sex hormones reflect overstimulation of physiological routes or whether alternative mechanisms become available once threshold values have been reached. In this presentation an attempt has been made to answer some of these questions using data obtained from a study of the regulation of the activities of microsomal 3 alpha- @entity14128 dehydrogenase (3 alpha-HSDH) and 5 alpha-reductase in @entity35 liver. Androgens exert their primary physiological and pharmacological influences at the level of the hypothalamus. Oestrogens can elicit three different types of effect-physiological, antiandrogenic and pharmacological--of which the first two involve primary effects on the pituitary. Hepatic @entity2931 receptors only become activated when @entity2931 concentrations reach pharmacological levels. @entity7828 probably have no physiological influence on the livers of non-pregnant @entity35 . Their pharmacological actions may either be traced back to secondary androgenic (e.g. @entity11796 , @entity2692 ) or oestrogenic (e.g. @entity8472 , @entity31426 ) properties, involving the routes described above, or to independent effects on the central nervous system (e.g. @entity3429 modulation of 5 alpha-reductase activity).
