Kisspeptin is a key player in the central control of reproductive axis. Central administration of kisspeptin has been shown to advance puberty in rats. Stimulation of hypothalamic GnRH pulse generating mechanism by kisspeptin has been proposed to be the mechanism behind the onset of puberty. We hypothesized that chronic high doses of kisspeptin administration suppresses the reproductive axis and hence delays the pubertal onset. Hence, we investigated the effect of peripheral administration of chronic high doses of kisspeptin on pubertal onset, feed intake and body weight in female rats. Rats were treated with saline or kisspeptin (100 nmoles per day; intraperitoneal) for 26 days (day 25 to day 50 postnatal) and the day of vaginal opening was marked as day of puberty. Kisspeptin treated rats had delayed pubertal onset and reduced feed intake and body weight. Gonadal GPR54 mRNA was reduced suggesting that chronic high doses of kisspeptin may suppress the reproductive functions possibly by downregulation of GPR54 receptor. However, delay in puberty due to reduction in feed intake and body weight could not be ruled out in this study. Further, our study emphasizes the importance of dosage and duration of kisspeptin administration in the manipulation of reproductive axis. Our study, for the first time, suggests that kisspeptin and its analogues, if proven beneficial, could be used to treat precocious puberty in children. It appears that, though a promising tool for enhancing fertility, kisspeptin acts as a double-edged sword and has to be cautiously used to manipulate reproduction.

Sperm recovery from epididymis in animals considered as important tools to preserve high-value or endangered species. However, there are no appropriate castrating indicators of timing for recovery of sperm which can be available to artificial reproduction technologies such as artificial insemination (AI) and in vitro fertilization (IVF), particularly in young Hanwoo bull. Therefore, this study aimed to investigate semen volume, morphology and motility of sperm in epididymis of young Hanwoo bulls at 8, 13, 14, and 15 months of age. About 2 cm of the epididymal tail only was cut and minced using blades. Minced epididymal tail tissues were mixed with semen extender (OptixCell, France, IMV technologies) and sperm were recovered with a cell strainer (100 μm nylon mesh). The number of sperm at 8 months of age was lower than that at 13, 14, 15 months of age in bulls after collection (33.6±27.2 vs. 352.4±39.2, 320.4±113.6 and 422.8±252.4×107cells respectively; P<0.05). After the frozen-thawed sperm the the percentage of abnormal head, tail and dead damaged acrosome did not differ between the ages 13, 14 and 15 months of age in bulls (P>0.05), however, the dead sperm with intact acrosome (DIA), the numbers showed that more than 15 months in 8, 13, 14 months (8.7±4.1 vs. 47.3±12.2, 34.8±14.0, 28.8±8.5, P<0.05). In addition, frozen-thawed sperm at 8 months of age showed low total motile sperm compared to those at 13, 14 and 15 months of age (26.4±8.2 vs. 45.7±29.5, 62.3±41.0, 70.4±15.9%, respectively; P<0.05). In conclusion, sperm derived from epididymal tail at 8 months of age in Hanwoo bulls showed high abnormal morphology and poor motility, which is not adequate for artificial insemination(AI) and in vitro fertilization(IVF). On the other hand, sperm derived from epididymal tail at 13, 14, 15 months of age in bull showed high normal morphology and motility, which may be available for AI and IVF. Epididymal sperm collected from bulls over 13 months is needed for further study whether to use the actual in vitro fertilization.

The purpose of this study was to investigate improvement of food habits and eating behavior in children with obesity andprecocious puberty by nutritional education monitoring. The results are as follows. Average height and weight of subjectsexceeded Korean height and weight standards for children as outlined by The Korea Pediatric Society. Using nutritioneducation monitoring, meals became more regular, overeating significantly decreased, and eating speed decreased. Further,frequencies of eating-out and night-eating significantly decreased. The most preferred menu item when eating-out wasKorean food, and the most preferred menu item for night-eating was fruits, fast food, & processed food. Meat & fish andvegetable intakes all significantly increased. Fruit and milk intakes also significantly increased while bread, snack, and icecream intakes decreased. Further, fast food & instant food intakes decreased. However, water intake was not significantlyaffected. The favorite food of children was meat & fish, followed by fast food & processed food. This study may provideinformation on dietary behavior of children with obesity and precocious puberty and suggests that nutrition education orcounseling can improve food habits and eating behavior.

Although the majority of surviving pigs cloned by somatic cell nuclear transfer (SCNT) appear to be physiologically normal, there is a general lack of detailed hemato-physiologic studies for the period of early adulthood to substantiate this claim. In the present study, we investigated variation in blood chemistry and endocrinological parameters between mesenchymal stem cells (MSCs) derived from cloned and normal age-matched female and male miniature pigs. Cloned females and males showed normal ranges for complete blood count assessments. Biochemical assessments showed that γ-GGT, ALT and cholesterol levels of male and female clones were significantly (P<0.05 or P<0.01, respectively) higher than that of age-matched control miniature pigs. Variations in insulin and IGF-1 were higher in female clones than in male clones and controls. Thus, although female and male cloned miniature pigs may be physiologically similar to normal animals, or at least within normal ranges, a greater degree of physiological and endocrinological variation was found in cloned pigs. The above variation must be taken into account before considering cloned female or male miniature pigs for various biomedical applications.

Background & Objectives: Methoxychlor(MET), an organochlorine insecticide, has been thought a potent endocrine disrupting chemical. The present study was undertaken to examine whether short-term exposure to MET can alter the onset of puberty and the associated reproductive parameters such as hormone receptor expressions in prepubertal female rats. Method: MET (1, 10 and 100 mg/kg/day) was administered daily from postnatal day 25 (PND 25) through the PND 34, and the animals were sacrificed on the PND 35. The first V.O. day was monitored, and the weights of reproductive tissues were measured. To assess the structural alterations in the ovary and uterus, the tissues were embedded in paraffin and stained for histological analysis. The transcriptional activities of hypothalamic and pituitary genes were measured using quantitative RT-PCRs. The uterine and hypothalamic proteins were extracted and used for the ER western blotting. Results: As a result, 100 mg group showed advanced V.O. than control, 1 mg group and 10 mg group. The wet weights of ovaries from MET-treated animal dose-dependently increased. The uterine weights were increased in 1 mg group and 10 mg group, while the 100 mg group samples were not significantly different from control tissues. The adrenal, kidney, spleen and thymus weights were not shown any significant change. Corpora lutea and fully grown follicles were observed in the ovaries from the 100 mg group, while numerous primary and secondary follicles were observed in the ovaries from control group. Myometrial thickness of MET-treated group was dose-dependently increased. Epithelial hypertrophy and well-developed glands were observed in the uterus from the 10 mg groups. Conclusions: The present study demonstrated that the short-term exposure to MET during the critical period of prepubertal stage could activate a reproductive endocrine system, resulting the early onset of puberty in immature female rats. Our study suggests that MET’s disrupting effect might be derived from premature activation of key reproduction-related genes in hypothalamus-pituitary neuroendocrine circuit.

The aim of this study was to investigate the clinical relations of eating behaviors to body mass index (BMI) and obesity in girls with idiopathic central precocious puberty. This study included 30 precocious puberty patients who were diagnosed at Chosun University Hospital between February and December 2013. Information was obtained from their parents using a questionnaire focused on eating behaviors and lifestyle factors. We rechecked their BMI and questionnaire after 12 months to identify the changes. Six (20%) of the 30 patients children were overweight and obesity at diagnosis. Overweight and obesity group tended to overeat. Normal weight group ate an unbalanced diet more than overweight and obesity group, particularly lack of fruit and vegetable (p=0.010). Eight (27%) of the 30 patients children were overweight and obesity and 24 (80%) of the 30 patients children showed increased BMI after 12 months follow up. BMI-decreased group ate breakfast with whole family members more frequent than BMI-increased group (p=0.006). This study showed the importance of healthy diet during treatment of precocious puberty. Children with precocious puberty should avoid overeating and make a balanced diet with preferable eating behaviors from the family meals.

In mammals, puberty is a dynamic transition process from infertile immature state to fertile adult state. The neuroendocrine aspect of puberty is started with functional activation of hypothalamus-pituitary-gonadal hormone axis. The timing of puberty can be altered by many factors including hormones and/or hormone-like materials, social cues and metabolic signals. For a long time, attainment of a particular body weight or percentage of body fat has been thought as crucial determinant of puberty onset. However, the precise effect of high-fat (HF) diet on the regulation of hypothalamic GnRH neuron during prepubertal period has not been fully elucidated yet. The present study was undertaken to test the effect of a HF diet on the puberty onset and hypothalamic gene expressions in immature female rats. The HF diet (45% energy from fat, HF group) was applied to female rats from weaning to around puberty onset (postnatal days, PND 22-40). Body weight and vaginal opening (VO) were checked daily during the entire feeding period. In the second experiment, all animals were sacrificed on PND 36 to measure the weights of reproductive tissues. Histological studies were performed to assess the effect of HF diet feeding on the structural alterations in the reproductive tissues. To determine the transcriptional changes of reproductive hormone-related genes in hypothalamus, total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Body weights of HF group animals tend to be higher than those of control animals between PND 22 and PND 31, and significant differences were observed PND 32, PND 34, PND 35 and PND 36 (p<0.05). Advanced VO was shown in the HF group (PND p<0.001) compared to the control (PND ). The weight of ovaries (p<0.01) and uteri (p<0.05) from HF group animals significantly increased when compared to those from control animals. Corpora lutea were observed in the ovaries from the HF group animals but not in control ovaries. Similarly, hypertrophy of luminal and glandular uterine epithelia was found only in the HF group animals. In the semi-quantitative RT-PCR studies, the transcriptional activities of KiSS-1 in HF group animals were significantly higher than those from the control animals (p<0.001). Likewise, the mRNA levels of GnRH (p<0.05) were significantly elevated in HF group animals. The present study indicated that the feeding HF diet during the post-weaning period activates the upstream modulators of gonadotropin such as GnRH and KiSS-1 in hypothalamus, resulting early onset of puberty in immature female rats.

Dicarboximide계 살균제인 vinclozolin(VCZ)은 과일, 야채, 관상용 식물에서 미생물에 의해 유발되는 병들을 통제하는데 사용되어왔다. VCZ의 대사산물인 M1과 M2는 흔히 토양, 식물, 포유류에 잔존하기 때문에 인간에게 노출될 가능성이 크다. VCZ가 갖는 항안드로겐성 활성 때문에 주로 수컷에 대한 연구가 이루어졌으며, 암컷의 사춘기와 생식계에 미치는 영향은 연구가 미비한 실정이다. 따라서 본 연구는 VCZ가 암컷 흰쥐의 사춘기 개

전세계적으로 매년 대량생산되는 프탈레이트(phthalate)류 물질은 플라스틱처럼 다양한 생활용품의 원료로 사용되기 때문에 인간에 대한 노출 정도가 매우 높은 산업 물질이다. 대표적으로 di(2-ethyl hexyl)phthalate(DEHP)와 그 활성 대사물인 monoethyl hexyl phthalate(MEHP)가 내분비계 장애물질(endocrine disruptor)로 작용하여 인간과 실험 동물의 생식계를 교란한다는 증거들이 급속히 축적되고 있

콩류 섭취가 유방암이나 골다공증, 그리고 심혈관계 질환 예방에 도움이 된다는 사실은 학계는 물론 일반인들에까지 큰 관심을 불러 일으키고 있다. 그러나 콩류, 특히 그 주성분인 genistein(GS)이 상기한 긍정적인 효과 외에도 여성의 생식계에 잠재적으로 부정적인 영향을 미칠 가능성에 대한 의문이 계속되어 왔다. 본 연구에서는 GS가 암컷 흰쥐의 사춘기 개시에 미치는 효과와 호르몬 수용체 등 이때의 다양한 생식 지표들의 변화들 조사하였다. GS(100