Endocrine disruptors have been concerned in toxicology but now challenged as physiological point especially concerned with exposing dose and period. In this study the low-dose chronic administration of di(2-ethylhexyl) phthaltae (DEHP) during reproductive period was examined to evaluate the possible roles. Adult male and female CD-1 mice were exposed to DEHP with drinking water containing 133 g/L and 1,330 ㎍/L DEHP in water according to OECD 433 guide line and sacrificed just after weaning. The weights of uterus and ovary were decreased by drinking of 1,330 ㎍/L DEHP water. There was not adverse effects on either accumulated mating rate and mating rate depend on estrus stage, pregnancy duration, and sex ration at birth. However, the accumulated rate of successful delivery and litter size were significantly high at 1,330 ㎍/L DEHP water. The number of epididymal sperm was significantly increased by drinking of 1,330 ㎍/L DEHP water. In addition, the number of follicles (primary, secondary, tertiary) were more many than control at 1,330 ㎍/L DEHP water drunk mother. Though further studies are needed to identify what are the mechanism of DEHP in folliculogenesis and spermatogenesis. From this study we firstly report the effect of low-dose chronic administration of DEHP with drinking could change the ovarian follicle population size and spermatogenesis rate. Put together, those finding is different from previous high-dose effects and suggest the physiological role of DEHP in gonads and uterus.

The greater horseshoe bat (Rhinolophus ferrumequinum) is distributed throughout Europe, Africa, Australia, and South Asia. It habits mainly in the cave in small groups and forming communities in late spring. It has interesting reproductive behavior because it keeps sperm for a few months in female reproductive tracts and then those sperms attend in fertilization. This breeding pattern is a sperm storage type and belongs to Rhinolophidae or Hipposideridae. The greater horseshoe also habits in Korea. However, the reasons of reproductive behaviors has not much uncovered. In this study the characters of ovary and the levels of steroid hormones were investigated from September to November. The histological, ELISA, and immunohistochemical methods were employed. The pre-ovulatory follicle was detected only at October sample. On the other hand, the blood level of testosterone was not detectable but the levels of 17β-estradiol and progesterone were exist within the detectable range. E2 and P4 levels were peak in October. Besides, the key enzymes for estradiol synthesis, CYP17 and CYP19 were localized in the theca layer and granulosa cells, respectively. October is known as mating time in this species. However, progesterone receptors could not detect at this period. Put together, it is suggested that, the increase of estrogen and the absence of progesterone receptors on preovulatory follicle is the cause of the mating without ovulation. The understanding of the expression regulation in this system will be base of the understanding the anovulation in mammals.

4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-dose NP exposing. This study was designed by following the OECD test guideline 443 and subjected to a complete necropsy. In male, NP had an effect on the weight of the testis and epididymis in both F0 and F1. In females, NP decreased the weight of ovary and uterus in F0 but not in pre-pubertal F1 pubs. Fertility of male and female in F0 or F1 was no related with NP administration. The number of caudal-epididymal sperm by body weight (BW) was not different between groups in both F0 and F1. Besides, the difference of the sperm number between generations was not detected. The number of ovulated oocytes was similar between groups in F0, but significantly decreased in NP 50 group of F1. The litter size and sex ratios of offspring in F1 and F2 were not different. The accumulated mating rate and gestation period were not affected by the NP administration. Those results shows that chronic lower-dose NP administration has an effect of endocrine disruptor on the weight of gonads and epididymis of F0 and F1 but not in reproduction. Based on the results, it is suggested that chronic lower-dose NP exposing causes endocrine disruption in the weight of gonad and epididymis but not in the reproductive ability of next generations.