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.

Adipogenesis is a primary energy valancing response in physiological status and critical in embryo development. One of the essential factors for initiation and maintaining of adipogenesis is the composition of extracellular matrix. Previously, we confirmed the effects of diphlorethohydroxycarmalol (DPHC), an extract of Ishige okamurae, on the antiobesity effects and ECM stability in adipose tissue. In vitro model for adipogenesis study, 3T3-L1, a precursor cell type of adipocyte, and the adipose-tissue derived stem cell (ADSC) can be used. Usually the induction period for adipocyte is shorter in 3T3-L1 than in ADSCs. However, so far, the difference of the expression patterns of ECM components in 3T3-L1 and ADSCs, and the effects of DPHC are not much known. We induced differentiation of 3T3-L1 and ADSCs into adipocyte with or without DPHC (0, 0.4, 2, 10, 50 μg/mL) and confirmed the adipogenesis with adipogenic markers (PPAR-γ, LDL). After then, the levels of collagen type 1 alpha 1 (Col1a1), collagen type 3 alpha 1 (Col3a1), collagen type 4 (Col4), collagen type 6 (Col6), Elastin (Eln) and microfibrillar associated protein 5 (Mfap5) were analyzed with real-time RT-PCR. During early adipogenesis of ADSC, the expression levels of Col1, Col3, Col6, and Mfap5 mRNA were decreased but Col4 and Eln mRNA were increased. In the matured adipocyte, the expression levels of Col1, Col3, Col4, Mfap5 mRNA were decreased but not Eln. In the case of early differentiation of 3T3-L1, the expression levels of Col1, Col3, Eln mRNA were decreased but the expression levels of Col6 and Mfap5 were increased. In matured adipocyte of 3T3-L1, the expression levels of Col1, Col3, Eln, Mfap5 mRNA were increase but the expression level of Col6 mRNA was decreased. The expression levels of Col4, Eln mRNA were suppressed by 50 mg/mL DPHC treatment during early adipogenic period of ADSC. On the other hand in 3T3-L1, the expression levels of Col3 and Col6 mRNA were not changed by the DPHC treatment during early induction period. In the matured adipocytes derived from ADSC, Col1 mRNA levels was not decreased by the treatment of 50 mg/mL DPHC. Col4 mRNA levels was not increased by DPHC treatment. In the case of matured adipocytes derived from 3T3-L1, DPHC suppressed the increase of Col1, Col3, Col6 mRNA expression and the expression of Col4 and Eln mRNA was decreased. In summary, these data show that expression levels of each ECM component types are dramatically changed with some common patterns in two cell types, and the treatment of DPHC can modify the expression patterns of some ECM components in each cell types. It is suggested that one of the reason of antiadipogenic effect of DPHC may be the ECM modification.

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.