Hormonal effects from exogenous

Hormonal effects from exogenous estrogens csm mimic excessive activity of normal eiKlogeiKius hormones. Estrogenic mycoloxins, plants, ond feed additives may alter reproductive cycles. 

The effects of exogenous steroids can differ from those of endogenous steroids in several ways. First, the biological activity of exogenous sex hormones can be much stronger. Second, they may be metabolized differently, and third, they may induce effects that are different from those of endogenous steroids. I21 ... 

Brown and West later showed that adrenaline, when given with dextran or g-white intradermally or subcutaneously, is considerably more active than noradrenaline in suppressing the subsequent reaction. They suggest that an effect on carbohydrate metabolism may be involved since exogenous glucose also prevents the response. However, the sympathomimetic amines in much smaller doses also inhibit inflammatory effects of bradykinin, and in this case exogenous glucose exerts only a feeble inhibitory effect. From these and other experiments they conclude that adrenaline, and possibly noradrenaline, may act as local anti-inflammatory hormones in the tissues. 

The administration of exogenous thyroid hormone (either triiodothyronine or thyroxine) to normal male rats reduces the metabolism of hexobarbital and aminopyrine by microsomal enzymes to about 50% of control levels but increases the metabolism of these substrates by microsomes from female rats. Thus, the effect of exogenous thyroid hormone on microsomal drug metabolism is similar to that of adrenalectomy and results in a diminution in the magnitude of the sex difference. 

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