Pituitary functional disturbances

Lead exposure may impair the endocrine function of male animals, probably through disturbance of the hypothalamic-pituitary function (Erfurth et al. 2001). Furthermore, lead has been shown to induce testicular atrophy, and to reduce spermatogenesis, affect the spermatozoa and to reduce sperm motility (US EPA 1986, Skerfving 1993). 

A consistent lowering of gonadotropin excretion was evident. Apparently this was not related to the occurrence of liver damage but was influenced by the degree of malnutrition. This would imply that the disturbances in pituitary function were probably the direct result of diminished food intake per se. 

Neuropsychological impairments in mood disorders, particularly those of working memory and executive function, are the most convincing and objective demonstrations of an impairment of consciousness. Since these impairments do not correlate with the severity of the mood disturbance and persist upon recovery they are not simply epiphenomena of the mood disturbance but rather may index trait pathology in susceptible individuals. It has previously been argued that mood disturbance and neuropsychological impairment may result from disturbances in two different neurochemical systems, the serotonin (5-HT) system and the hypothalamic-pituitary-adrenal (HPA) axis, between which there is a close interaction (McAllister-Williams et al., 1998). 

A patient developed a severe headache, nausea and vomiting, visual disturbance, and altered mental function 88 hours after a protirelin/gonadorelin stimulation test to investigate a pituitary macroadenoma (16). Bleeding into the tumor was seen on CT scan. The patient died 9 days later of pneumonia. 

Mental disorders, also called affective disorders, are multi-level, multi-scale and multiple-system diseases (Fig. 7.1). Mental disturbances generally go along with disturbances of autonomous functions. These essentially are (1) sleep disturbances, both sleep duration and sleep pattern, and (2) disturbances of the hypothalamic-pituitary-adrenal (HPA) axis, the so-called stress axis with elevated cortisol levels. It can be expected that disturbances of autonomous control systems as well as mood are caused by neuronal malfunctioning which may concern practically all neuronal levels systemic interactions, neuronal network connections, single neuron dynamics, synaptic transmitters and/or receptors, ion channels, second messengers, and gene expression (Fig. 7.1a). Nevertheless, despite a manifold of data, there are only vague ideas so far about the differences in neuronal dynamics in the brain of a chronically depressed person compared with a person with a sensitive but balanced mood. 

In female animals, lead may disturb the hypothalamus-pituitary-ovarian-uterine function (Govoni et al. 1984), causing altered menstrual cycles. Implantation problems may then appear. Furthermore, lead exposure may decrease the blood flow throw the placenta and affect the heme metabolism of the fetus (US EPA 1986). 

Though less frequently sought, endocrine disturbances form an essential part of the clinical picture in malnutrition. Their importance has been emphasized by Samuels (1948), Zubirdn (1949), and by Gillman and Gillman (1951). The similarity between the clinical manifestations of malnutrition and those of altered endocrine function are evidenced by the frequency of serious sexual disturbances, pigmentations of the skin, lowered metabolic rates, gynecomastia, asthenia, hypotension, and other symptoms which could be attributed to dysfunction of the thyroid, the adrenals, the pituitary, or the gonads in undernourished individuals. 

The diminished excretion of pituitary gonadotropins which was observed in our patients was mentioned previously in connection with the disturbances of ovarian and testicular function. In Table VIII a summary... 

---