ABSTRACT
G.O.EVANS The endocrine system plays an important role in regulating major physiological functions including maturation, reproduction and reactions to external stimuli. Some endocrine organs appear to be more responsive or vulnerable to xenobiotics, and this may result in rapid responses such as those observed for catecholamines and glucocorticoids. However, the majority of effects caused by xenobiotics require longer periods of exposure before the toxic changes are observed, e.g. effects on the pituitary gland or following indirect hormonal changes related to hepatic microsomal enzyme induction. Endocrine changes may be hypo-or hyper-functional due to suppression or following stimulation.
