Female Reproductive Development

Breast Cancer. Many studies have observed low incidences of hormone-dependent cancers, particularly breast cancer, in Asian countries compared with Western countries and it is becoming increasingly accepted that dietary factors play an important role. Although breast cancer can occur in either males or females, only about 1 % of all cases occur in men, and male breast cancer is a rare disease in all parts of the world." Although there appear to be some similar risk factors for breast cancer in males and females, there is no indication in the literature that diet is either a risk or a protective factor for male breast cancer. The development of breast cancer is known to be highly dependent on the hormones associated with female reproductive functions, while established genetic factors have been... 

The estrogens are secreted by the ovarian follicle and in smaller amounts by the adrenal cortex. Estrogens are important in the development and maintenance of the female reproductive system and the primary and secondary sex characteristics. At puberty, they promote growth and development of the vagina, uterus, fallopian tubes, and breasts. They also affect the release of pituitary gonadotropins (see Chap. 50). 

Endosulfan administered by gavage at 1.5 mg/kg/day for 30 days to ovariectomized rats did not influence the relative weights or histology of the uterus, cervix, or vagina compared to ovariectomized control rats that did not receive endosulfan (Raizada et al. 1991). Rats in a positive control group received intraperitoneal injections of estradiol and showed increased relative organ weights and normal development of female reproductive tissues compared to the untreated ovariectomized control rats. 

In vivo studies in animals suggest that endosulfan may disrupt normal reproductive hormone levels in male animals, but that it is not an endocrine disrupter in females. Persistent depressed testicular testosterone was seen in male rats after intermediate duration oral exposures to endosulfan. In ovariectomized female rats, orally administered endosulfan did not induce normal development of female reproductive tissues, and in female mice and immature female rats, acute parenteral exposure to endosulfan did not affect several endocrine-related end points. In vitro studies have evaluated endosulfan for estrogen receptor (ER) and cytosolic protein binding affinity, ER-mediated reporter gene expression, estrogenic induction of cell proliferation, and alteration of relative abundance of active estradiol metabolites. Overall, in vitro evidence in favor of endosulfan estrogenicity indicates relatively weak potency compared to 17[3-estradiol. Apparently contradictory results were reported in different... 

Foetal development promotes growth and differentiation of foetal cells and organogenesis Promotes longitudinal body growth and increased body weight Promotes enhanced functioning of the male and female reproductive tissue Promotes growth and differentiation of neuronal tissue... 

FSH and LH play critical roles in the development and maintenance of male and, particularly, female reproductive function (Box 11.3). hCG, produced by pregnant women, plays a central role in maintaining support systems for the developing embryo during early pregnancy. All three are... 

Gray, L. E., et al. (1997b). In utero exposure to low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters reproductive development in female Long Evans hooded rat offspring. Toxicology and Applied Pharmacology, 146, 237-244. 

The demonstration of this behavioural response to a male pheromone signal is significant because of the manner in which the pheromone was delivered. Most other vertebrate examples of reproductive pheromones involve reception via the olfactory system(s). In contrast, D. ocoee females received the pheromone via diffusion through the dorsal skin. We assume that the well developed superficial capillary system of these lungless salamanders is the route by which the male pheromone was transported to whatever target tissue(s) initiated responses that affected female reproductive behaviour. 

C. Implantation to closure of the hard palate Adult female reproductive functions and development of Segment I Segment II Segment I Segment II Segment II Multigeneration One-generation developmental toxicity Developmental neurotoxicity... 

Adult female reproductive function, fetal development, and growth and organ development and growth. 

Phthalates are suspected of acting as endocrine disrupters also in humans, affecting male and female reproductive tract development. Exposure to PAEs in adult men has been associated with semen quality and alterations in sexual behavior [104], and with endometriosis and intrauterine inflammation (which is a risk factor for prematurity) in adult women [105, 106], as well as other effects. These studies suggest that DEHP may play a role in inducing the intrauterine inflammatory process. Besides the reproductive effects of PAEs, recent studies have also shown the genotoxicity of DEHP, DBP, and DiBP in human lymphocytes and mucosal cells [107,108]. 

Exposing young male prairie deer mice, Peromyscus maniculatus, to soiled bedding from adult male conspecifics retards the growth of their testes and seminal vesicles. Male, but not female, urine applied to the nose has the same effect. Removal of the olfactory lobes at the age of 3 weeks blocks this effect (Lawton, 1979). The reproductive development of male California voles, M. californicus, is suppressed hy chemical cues from the mother (Rissman etah, 1984). 

Reasner, D. S. and Johnston, R. E. (1988). Acceleration of reproductive development in female Djungarian hamsters by adult males. Chemical Senses 13,729. 

Reproductive toxicity to 2,3,7,8-TCDD has been demonstrated in animals. "" The effects include pre- and postimplantation losses in females, morphologic and functional changes in male and female reproductive organs, and hormonal imbalance in both sexes. A number of developmental effects have been observed in animals acutely exposed to 2,3,7,8-TCDD by the oral route. Effects observed in offspring of animals include cleft palate, kidney anomalies, immune system damage (thymic atrophy and immunosuppression), impaired development of the reproductive system, decreased growth, and fetal/newborn mortality. 

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