Hormone general properties

Recently, leaders in the pharmaceutical industry have developed a list of desired properties for a fourth generation of SERMs (Table 2). In general, future SERMs must oppose endogenous hormone action in the breast and reproductive system while displaying full estrogenic effects in the cardiovasculature, bone and central nervous systems. Additional criteria are that fourth generation compounds possess superior bioavailability compared with existing SERMs and have... 

Hormones can be classified according to chemical composition, solubility properties, location of receptors, and the namre of the signal used to mediate hormonal action within the cell. A classification based on the last two properties is illustrated in Table 42-3, and general feamres of each group are illustrated in Table 42-. ... 

Steroid hormones form a group of pollutants that includes natural hormones such as estradiol, testosterone, and their metabolites as well as several synthetic analogues. Steroid hormones used as growth promoters have already been found in water and sediments (Lai et al. 2000 Thorpe et al. 2003), and their adsorption properties on earth materials have been considered. Lee et al. (2003) report batch experiments where simultaneous sorption of three hormones (17- 3-estradiol, 17-a-ethyl estradiol, and testosterone) on four midwestem U.S. soils and a freshwater sediment were performed. Apparent sorption equilibria were reached within a few hours. Sorption isotherms generally were linear for the chemicals studied on one of these soils (Drummer soil), ranged from 23.4 to 83.2 L kg and log ranged... 

Likewise, mechanisms responsible for the developmental effects observed in laboratory animals exposed to chlorine dioxide or chlorite are not known. They might be related to the oxidative properties of these chemicals. Although overt signs of neurodevelopmental effects (delays in exploratory activity and general locomotor activity) and altered serum th5Toid hormone have been observed concurrently in animals that had been exposed via their mothers during pre and postpartiun development, a mechanistic basis has not been investigated. 

The aforementioned synthetic modeling approach, which was so successfully applied to studying the structural properties of /3-endorphin, appears to be general and has been applied to the study of several other peptide hormones and hormone-releasing factors including glucagon... 

These inhibitors would be classified as anti-juvenile hormones and could be expected to show selective action on insects as a class. Such analogs are by no means just around the corner since at least two important properties that they should possess may be difficult to build into small organic molecules suitable for pest control. These properties are the ability to withstand general metabolic inactivation while retaining the ability to inhibit irreversibly the target enzymes of the corpus allatum and the property to accumulate selectively in corpora allata, a physically small target, so as to offset dilution in the general body cavity. 

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