Monoamines and ovarian hormone-linked sexual and emotional changes: A review

Emotional upsets related to changes in ovarian hormones are highly prevalent and are responsible for psychiatric morbidity and mortality. Significant increases in acute psychiatric hospitalizations, suicidal activity, and other psychopathology occur during the premenstruum and during menstruation. This paper reviews evidence indicating that menstrual cycle psychopathology may be mediated by the effects of estrogen, progesterone, and possibly the renin-angiotensin-aldosterone system on the brain monoamines, norepinephrine, dopamine, and serotonin. During the menstrual cycle, psychopathology often begins with the onset of luteal estrogen-progesterone-angiotensin-aldosterone secretion and intensifies as these hormone levels later fall, prior to and during menstruation. Aldosterone is reported elevated in cases of premenstrual tension syndrome. There are numerous reports of affective upsets occurring with the use of estrogen-progestin oral contraceptives and following their withdrawal. Contraceptives stimulate the renin-angiotensin-aldosterone system and are reported useful in alleviating premenstrual-menstrual emotional upsets and postpartum depressive episodes. Affective lability, prevalent at parturition, occurs when estrogen, progesterone, and aldosterone levels are first high and later falling. Exogenous estrogen and progesterone profoundly affect mating activity in castrated rhesus monkeys, and cyclic fluctuations in sexual activity in humans may occur during the menstrual cycle. Much information links manic and depressive reactions with alterations in brain monoamines. Lithium, monoamine oxidase inhibitors, and tricylic antidepressants, specifically used to treat affective disorders, are reported useful in treating ovarian hormone-linked upsets. Similarities exist between changes in animal behavior caused by drugs altering affective states and the effects of ovarian hormones. Like certain antidepressants, estrogen induces hyperactivity in rats. Like reserpine, progesterone exhibits sedative and soporific effects. Sexual behavior in female rats is reported linked to changes in brain monoamines. Agents increasing brain monoamine levels and availability decrease mating responses, and monoamine depletors, such as reserpine may be substituted for progesterone in activating mating behavior. Serotonin and dopamine appear to be important in the regulation of ovulation. Brain norepinephrine varies with the phases of the rat estrus cycle. Castration increases brain norepinephrine and decreases brain dopamine. Exogenous estrogen decreases rat brain norepinephrine content. The monoamine-destroying enzymes, monoamine oxidase, and catechol O-methyl transferase are affected by ovarian steroids and show fluctuating levels during the reproductive cycle. The effects of reserpine, monoamine oxidase inhibitors, tricyclic antidepressants, and lithium on monoamines in neurophysiological preparations have been used as evidence supporting theories linking monoamine changes with human affective disorders. Estrogen, progesterone, and angiotensin also exhibit effects on in vitromonoamine systems. Like the tricyclic antidepressants, uptake of norepinephrine and dopamine by nerve endings is inhibited in the presence of estrogen, progesterone, and angiotensin. As with reserpine, the flow of these monoamines from nerve endings is increased by progesterone. Estrogen slows the flow of norepinephrine from nerve endings and decreases the electrically induced release of serotonin and norepinephrine from brain slices. The above information provides clues that ovarian hormone-linked psychopathology, like affective disorders in general, may be related to alterations in brain monoamines.

The calcification of fibrous pleural lesions produced in guinea-pigs by the injection of chrysotile asbestos dust

In guinea-pig pleural granulomas produced by the injection of chrysotile asbestos dust, the initial cellular lesions were replaced by old acellular fibrous tissue within 15-18 months. After this period calcification of the fibrous tissue commonly occurred. The first sign of calcification was always the formation among the collagen fibres of large numbers of spherical lamellated bodies. These structures stained positive for acid mucopolysaccharides, and electron-microscope observations showed that they were formed around a core of asbestos dust. Calcium in the form of apatite crystals was also often present in these structures. Shortly after the formation of lamellar bodies the mucopolysaccharide normally present on the collagen fibres, was removed and instead it formed a thick coating around any free asbestos dust in the fibrous area. The first signs of general calcium deposition were seen both in contact with collagen fibres and on the surface of the coated asbestos dust. Eventually calcium deposits filled all the tissue spaces and enclosed collagen, coated asbestos dust and lamellar bodies in a solid mass of calcification.

The long term fibrogenic effects of chrysotile and crocidolite asbestos dust injected into the pleural cavity of experimental animals

In a series of experiments on the effects of chrysotile and crocidolite asbestos dust injected into the pleural cavities of experimental animals, the following results were obtained. Both dusts produced large granulomas in all the species used, but the histological patterns of these lesions varied. In guinea-pigs both chrysotile and crocidolite produced granulomas that consisted mainly of giant cells, mixed with a few macrophages and fibroblasts, and each granuloma was surrounded by a distinct capsule of fibrous tissue. In mice and rats, however, relatively few giant cells were present in the asbestos granulomas, and the lesions consisted only of macrophages with some fibroblasts. In these 2 species the granulomas were not surrounded by a distinct capsule. In all cases the granulomas were eventually replaced by masses of fibrous tissue, but the time sequence of this change was variable. In guinea-pigs the granulomas remained cellular for 6-12 months, and after this period there was evidence of the invasion of the lesions by fresh macrophages which rephagocytosed dust left behind by the death of previous cells. In mice some areas of the granulomas remained cellular for 12-15 months, but others were completely fibrosed by 6-9 months. In rats fibrosis of the asbestos granulomas was very rapid, and most lesions consisted of old almost acellular collagen by 3-4 months. In all species a few animals showed massive pleural fibrosis outside the main granulomas. In some cases this appeared to be associated with an infection spreading from the lung tissue, but in others no such association could be traced.