Sexual development

It is known that the brain is one of the most sensitive sites of action of steroids in utero, and recently there have been suggestions that EDs may affect normal brain development and behaviour. For example, it has been alleged that in utero exposure to polychlorinated biphenyl compounds (PCBs) resulted in adverse effects on neurologic and intellectual function (memory and attention) in young children born to women who had eaten PCB contaminated fish in the USA." It has also been speculated that exposure to environmental pollutants with steroidal activity may be infinencing human sexual development and sexually controlled behavioiir." ... 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

Lange, A., Katsn, Y., and Ichikawa, R. et al. (2008a). Altered sexual development in roach exposed to environmental concentrations of the pharmaceutical EE2 and associated expression dynamics of aromatases and estrogens. Toxicological Sciences (accepted). 

ASHBY J, TINWELL H, ODUME J, KIMBER I, BROOKS A N, PATE I, BOYLE C C (2000) Diet and the aetiology of temporal advances in human and rodent sexual development. J Appl Toxicol. 20 343-7. 

Fox GA. 1992. Epidemiological and pathobiological evidence of contaminant-induced alterations in sexual development in free-living wildlife. In Colbom T, Clement C, editors, Chemically-induced alterations in sexual and functional development the wildlife/ human connection. Princeton (NJ) Princeton Scientific Publishing Company, p. 147-158. 

Vandenbergh J.G. (1989). Coordination of chemical signals and ovarian function during sexual development. J Anim Sci 67, 1841-1847. 

The adrenal glands are important in the synthesis and regulation of key hormones. They play a crucial role in water and electrolyte homeostatsis, as well as regulation of blood pressure, carbohydrate and fat metabolism, physiologic response to stress, and sexual development and differentiation. This chapter focuses on pharmacologic and nonpharmacologic management of the two most common conditions associated... 

Amenorrhea traditionally is described as either primary or secondary in nature. Primary amenorrhea is the absence of menses by age 16 in the presence of normal secondary sexual development or the absence of menses by age 14 in the absence of normal secondary sexual development. Secondary amenorrhea is the absence of menses for three cycles or 6 months in a previously menstruating woman. However, in clinical practice, there is a significant amount of overlap. The initial evaluation of amenorrhea is often the same regardless of age of onset, except in unusual clinical situations.1... 

Cessation of menses for longer than 6 months in women with established menstruation, or absence of menses by age 1 6 in the presence of normal secondary sexual development, or absence of menses by age 14 in the absence of normal secondary sexual development... 

Growth and development Delay in growth (weight and height) and sexual development decreased fertility increased complications... 

Congenital adrenal hyperplasia A rare inherited condition resulting from a deficiency in cortisol and aldosterone synthesis with resulting excess androgen production. The clinical presentation depends on the variant of the condition, but it typically manifests as abnormalities in sexual development and/or adrenal insufficiency. 

Hypogonadism A condition resulting from or characterized by abnormally decreased functional activity of the gonads, with retardation of growth and sexual development or reduced or absent secretion of hormones from the sex glands resulting in low testosterone levels in men. 

Lubahn DB, Moyer JS, Golding TS, Couse JF, Korach KS, Smithies O (1993) Alteration of reproductive function but not prenatal sexual development after insertional disruption of the mouse estrogen receptor gene. Proc Nad Acad Sci USA 90 11162-11166... 

It is clear, therefore, that although there are interrelations between the gonadal sex hormones and the pituitary sex hormones involving also the adrenals, thyroids, etc., the effective hormonal impetus to sexual development arises in the pituitary. 

Kato, N., Brooks, W. and Calvo, A.M., Sterigmatocystin and penicillin pene expression is controlled by veA, a gene required for sexual development in Aspergillus nidulans. Eukaryotic Cell, in press. 

Diet may counteract or substitute for chemical cues that influence sexual maturation. Male California voles, Microtus californicus, for instance, are inhibited in their sexual development by odors from their mothers or unrelated females. This effect is eliminated if the regular diet is enriched with fresh lettuce. In young females, uterus growth is stimulated by the odor of males but, in the absence of males, fresh lettuce added to the diet can accomplish the same effect (Rissman and Johnston, 1986). This can be seen as another case of adaptive redundancy of cues for an important function. 

In rabbits, Oryctolagus cuniculus, urine of an adult female delays growth and sexual development in unrelated young males, while mother s urine also delays body growth, but it accelerates sexual development in her own sons. This can he seen as females manipulating the reproductive success of nearby conspecifics (Bell, 1986). 

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