Organs, reproductive

In addition to the organs responsible for the development and maintenance of the fetus and newborn, l,25(OH)2D3 receptors have also been localized in several organs from the reproductive apparatus such as the uterus [71], ovary [72] and testis [73]. Since these tissues are not directly associated with calcium translocations, the presence of l,25(OH)2D3 receptors may be related to a role of the hormone in cellular proliferation, differentiation and/or maturation. Accordingly, the levels of testicular l,25(OH)2D3 receptors have been found to correlate with the meiotic and mitotic development of the spermatogonia [73], Clearly, more studies are needed in this area to clarify the role of the vitamin D hormone in these tissues. However, 

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Stilboestrol Reproductive organs Improved reproductive capacity... 

Smooth muscle cells constitute the most diversified class of muscle cells. They are the parenchymal cells of many organs, including the uterus and other reproductive organs, gall bladder, urinary bladder, respiratory passages, etc. In all these cases,... 

Reproductive Toxicity—The occurrence of adverse effects on the reproductive system that may result from exposure to a chemical. The toxicity may be directed to the reproductive organs and/or the related endocrine system. The manifestation of such toxicity may be noted as alterations in sexual behavior, fertility, pregnancy outcomes, or modifications in other functions that are dependent on the integrity of this system. 

No studies were located that examined reproductive function in animals after inhalation exposure to endosulfan. However, routine gross and histopathological examination of the reproductive organs (testes, epididymides, seminal vesicles, prostate, ovaries, and uterus) of rats exposed (nose-only) to concentrations of endosulfan of up to 2 mg/m for 6 hours/day, 5 days/week for a total of 21 out of 29 days revealed no adverse effects (Hoechst 1984c). 

In summary, although the available reproductive studies indicate endosulfan has no adverse effects on reproductive performance in animals, adverse effects on male reproductive organs have been seen in young rats and mice. The lack of effects seen in the studies that examined reproductive performance (specifically fertility rate) in treated males and females seems difficult to explain, given the finding of altered spermatogenesis in the more recent studies. 

Another cumulative effect of radiation can be an irreversible alteration of DNA sequences. If part of a DNA molecule is ionized, its molecular chain may be broken. Chain breaks are repaired in the body, but after a serious rupture, the repaired unit may have a different sequence. This type of changed sequence is a genetic mutation. Altered DNA sequences in the reproductive organs are transmitted faithfully, thus passing on the genetic mutations to fiature generations. Because these effects are cumulative, individuals of childbearing age need to be especially carefial about radiation exposure. 

C22-0079. Why is it more important to protect the reproductive organs from radiation than other organs ... 

Histopathological changes in reproductive organs have not been observed in rats or mice treated by gavage with trichloroethylene in com oil for chronic durations (Maltoni et al. 1986 NCI 1976 NTP 1988, 1990). The highest doses used in these studies were time-weighted average doses of 1,097 mg/kg/day in rats,... 

Dermal exposure of male rabbits to unspecified doses of Cellulube 220 (1-4 hours/day, 4-5 days/week for <46 days) did not elicit histological alterations in the testes (Carpenter et al. 1959). Dermal exposure of male and female rabbits to cyclotriphosphazene at doses < 1,000 mg/kg/day for 6 hours/day, 5 days/week, for 21 days did not affect the reproductive organs (Kinkead et al. 1989c, 1990). No other dermal studies examining reproductive effects in animals were located. This NOAEL value for reproductive effects in rabbits acutely exposed to cyclotriphosphazene hydraulic fluid is recorded in Table 2-8. 

A mixed isomer preparation of TCP (containing <0.1% tri-ort/zo-cresyl phosphate) produced histological changes in reproductive organs in both sexes of rats and female mice in 13-week and 2-year bioassays (NTP 1994). Ovarian interstitial cell hypertrophy occurred in female mice and female rats exposed to gavage doses of 50-800 mg/kg/day for 13 weeks, in female rats exposed to dietary doses of 65 and 120 ng/kg/day for 13 weeks, and in female rats exposed to dietary doses of 9 or 18 mg/kg/day for 2 years (NTP 1994). Atrophy of the seminiferous tubules occurred in male rats that received gavage doses of 400 and 800 mg/kg/day for 13 weeks and in male rats exposed to dietary doses of 470 and 940 mg/kg/day for 13 weeks (NTP 1994). 

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