• Animal cells and systems
• /
• 제3권3호
• /
• pp.311-317
• /
• 1999

Prolactin (PRL) was reported to be locally synthesized in many brain areas including the hypothalamus, thalamus (TH) and hippocampus (HIP). In the pituitary lactotrophs, PRL synthesis is dependent upon a pituitary-specific transcription factor, Pit-1. In the present study, we attempted to identify Pit-1 or Pit-1-like protein in brain areas known as the synthetic sites of PRL. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis showed the same Pit-1 transcripts in brain areas such as the medial basal hypothalamus (MBH), preoptic area (POA), TH, and HIP with the Pit-1 transcripts in the anterior pituitary (AP). Electrophoretic mobility shift assay (EMSA) was run with nuclear protein extracts from brain tissues using a double strand oligomer probe containing a putative Pit-1 binding domain. Shifted bands were found in EMSA results with nuclear proteins from MBH, POA, TH and HIP. Specific binding of the Pit-1-like protein was further confirmed by competition with an unlabeled cold probe. Antisense Pit-1 oligodeoxynucleotide (Pit-1 ODN), which was designed to bind to the Pit-1 translation initiation site and block Pit-1 biosynthesis, was used to test Pit-1 dependent brain PRL transcription. Two nmol of Pit-1 ODN was introduced into the lateral ventricle of a 60-day old male rat brain. RNA blot hybridization and in situ hybridization indicated a decrease of PRL mRNA signals by the treatment of Pit-1 ODN. Taken together, the present study suggests that Pit-1 may play an important role in the transcriptional regulation of local PRL synthesis in the brain.

• 한국동물학회지
• /
• 제39권1호
• /
• pp.115-121
• /
• 1996

임신중기에서 발기에 이르는 흰쥐의 태반에서 Placental Lactogen I (PL-I), II 그리고 Pit-1 의 유전자 발현 변화를 Northern blot hybridization으로 조사하였다. 그 결과, 임신시기에 따라 PL-I과 PL-II의 mRNA 양과 크기에 변화가 나타났다. 이들 유전자 발현에 미치는 에스트로겐의 영향을 조사하기 위하여, 임신 14일째 쥐의 난소를 제거하고(OVX), 이후 매일 에스트로겐을 투여한 후 (OVX+E), 임신 18일째 태반을 회수하여 PL-I, II 그리고 Pit-1의 유전자 발현을 Northern blot hybridization으로 조사하였다. OVX 군의 경우, PL-I의 mRNA 크기는 1 kb에서 1.3 kb로 PL-II의 mRNA는 0.6kb에서 1 kb로 변화하였다. OVX+E 군에서는 PL-I과 PL-II의 mRNA가 정상대조군과 같은 상태로 환원하였다. 정상대조군에 비하여 OVX와 OVX+E 군에서 PL-I과 PL-II의 mRNA 크기에는 영향을 미치지 못한 반면, mRNA 양은 난소제거시 감소하였다가, 에스트로겐을 투여하면, 부분적으로 회복되는 경향을 보였다. 이러한 본 실험의결과는 에스트로겐이 PL-I과 PL-II의 RNA splicing이나 polyadenylation 등을 포함한 유전자 발현에 영향을 미치며, Pit-1이 이 과정에 개입하는 것을 시사하는 것이다.

• Animal cells and systems
• /
• 제6권3호
• /
• pp.247-252
• /
• 2002

The effect of paraquat (PQ, 1,1＇-dimethyl-4,4＇-bipyridium) on the histogene-sis and glycoconjugates (GCs) properties of the pyloric region of the stomach in a perinatal rat was examined by histological and histochemical methods. Oral administration of PQ (9 mg/kg per day in 0.2 mL of D.W.) on 7 to 14 days of gestation revealed growth retardation with significant reductions in the length of pyloric gland and their pit. As for histochemical properties of GCs in the pyloric region of the stomach, the PQ-treated rats showed some differences, such as delayed initial appearance of the sulfated GCs and lectin affinities compared with the vehicle group. These different GCs properties in the surface and gastric pit were usually detected in the fetal rats and more prominent and evident differences were revealed in the gland epithelium of the early postnatal rat. These results suggest that maternal PQ administration causes intrauterine growth retardation asso-ciated with delayed histogenesis and GCs immaturation of pyloric mucosa in developing rat.

• 한국동물학회:뉴스레터
• /
• 제12권2호
• /
• pp.100.1-100
• /
• 1995

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
• /
• pp.228.1-228
• /
• 1995

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
• /
• pp.140.1-140
• /
• 1996

No Abstract, See Full Text

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권8호
• /
• pp.3473-3477
• /
• 2015

Plants and their by-products offer a diverse mixture of chemical constituents like natural antioxidants. Date-pits are rich in phenolic compounds that have antioxidant potential. The main objective of this study was to investigate the protective effect of a date-pit extract (DPE) against AOM-induced colonic carcinogenicity and oxidative stress. Thirty-two weanling male Sprauge-Dawley rats were randomly divided into four groups (eight rats in each group). All rats were fed basic diet and water ad libitum, and randomly distributed per treatment groups as follows: negative controls injected with normal saline once a week for two weeks, a cancer group injected intra-peritoneally with azoxymethane (15mg/kg body weight) for two consecutive weeks, and DPE treated groups receiving the extract via the oral route (1.5ml/day) for the entire experiment in the presence or absence of AOM injection. Results showed that DPE contained phytonutrients that were capable of inhibiting chemically-induced oxidative stress in the rat colonic cells. In those animals that consumed DPE, a protective effect was observed against AOM-induced oxidative stress in rat colonic cells as evident by a significant decrease in MDA and oxidized DCF formation in AOM injected and DPE fed groups. It is concluded that DPE has potential antioxidant and anticarcinogenic properties.

• Korean Journal of Acupuncture
• /
• 제36권2호
• /
• pp.115-126
• /
• 2019

Objectives : Osteoporosis is a condition characterized by low bone mass and increased bone fragility. It has become a major problem of senior citizens. The purpose of this study is to experiment the effect of water extract of Forsythiae Fructus (wFF) on osteoclast differentiation; and the other purpose is to examine the effect of wFF on osteoporosis in ovariectomized rat. Methods : To investigate the effect of wFF on osteoclast differentiation and activity, RAW 264.7 cells were used. The number of TRAP positive cell, TRAP activity, pit area, mRNA expression of makers (RANK, TRAP, CA II, CTK, MMP-9, NFATc1, c-Fos), protein expression of makers (NFATc1, c-Fos) were investigated. For in vivo study, 40 female Sprague-Dawley (SD) rats were induced osteoporosis by ovariectomy (OVX) and then tested for anti-osteoporosis effect by administration of wFF. Results : wFF suppressed osteoclatogenesis, TRAP activity and pit area formation. Moreover, wFF decreased the expression of master differentiation factors (NFATc1, c-Fos) and also reduced the osteoclastogenesis-related markers (TRAP, CA II, CTK, MMP-9). These suggest that wFF inhibit osteoclasts differentiation and bone resorption. In the OVX rat model, wFF inhibited decreasing of BMD and trabecular area. Conclusions : Forsythiae Fructus should be effective for osteoporosis prevention and treatment.

• Clinical and Experimental Reproductive Medicine
• /
• 제23권3호
• /
• pp.269-275
• /
• 1996

Biosynthesis and secretion of anterior pituitary hormones are under the control of specific hypothalamic stimulatory and inhibitory factors. Among them, Growth Hormone Releasing Hormone (GHRH) is the major stimulator of pituitary somatotrophs activating GH gene expression and secretion. Human GHRH is a polypeptide of 44 amino acids initially isolated from pancreatic tumors, and the gene for the hypothalamic form of GHRH is organized into 5 exons spanning over 10 kilobases (kb) on genomic DNA and encodes a messenger RNA of 700-750 nucleotides. Several neuropeptides classically associated with the hypothalamus have been found in the extrahypothalamic regions, suggesting the existence of novel sources, targets and functions. GHRH-like immunoreactivity has been found in several peripheral sites, including placenta, testis, and ovary, indicating that GHRH may also have regulatory roles in peripheral reproductive organs. Furthermore, higher molecular weight forms of the GHRH transcripts were identified from these organs (1.75 kb in testis; 1.75 and >3 kb in ovary). These tissue-specific expression of GHRH gene suggest the existence of unique regulatory mechanism of GHRH expression and function in these organs. In fact, placenta-specific and testis-specific promoters for GHRH transcripts which are located in about 10 kb upstream region of hypothalamic promoter were reported. The use of unique promoters in extrahypothalamic sites could be refered in a different control of GHRH gene and different functions of the translated products in these tissues. Somatotrophs and lactotrophs have been thought to be derived from a common bipotential progenitor, the somatolactotrophs, which give origins to either phenotypes. Although the precise mechanism responsible for the lactotroph differentiation in the anterior pituitary gland has not been yet clalified, there are several candidators for the generation of lactotrophs. In human, the presence of GHRH peptides with different size from authentic hypothalamic form in the normal anterior pituitary and several types of adenoma were demonstrated. Recently our group found the existence of immunoreactive GHRH and its transcript from the normal rat anterior pituitary (gonadotroph> somatotroph> lactotroph), and the GHRH treatment evoked the increased proliferation rate of anterior pituitary cells in vitro. The transgenic mouse models clearly shown that GHRH or NGF overexpression by anterior pituitary cells induced development of pituitary hyperplasia and adenomas particularly GH-oma and prolactinoma. Taken together, we hypothesize that the pituitary GHRH could serve not only as a modulator of hormone secretion but as a paracrine or autocrine regulator of anterior pituitary cell proliferation and differentiation. Interestingly enough, the expression of Pit-1 homeobox gene (the POU class transcription factor) was confined to somatotrophs, lactotrophs and somatolactotrophs in which GHRH receptors are expressed commonly. Concerning the mechanism of somatolactotroph and lactotroph differentiation in the anterior pituitary, we have focused following two possibilities; (1) changes in the relative levels or interactions of both hypothalamic and intrapituitary factors such as dopamine, VIP, somatostatin, NGF and GHRH; (2) alterations of GHRH-GHRH receptor signaling and Pit-1 activity may be the cause of lactotroph differentiation or pituitary hyperplasia and adenoma formation. Extensive further studies will be necessary to solve these complicated questions.

• Journal of Preventive Medicine and Public Health
• /
• 제38권3호
• /
• pp.330-336
• /
• 2005

Objectives : The aim of this study was to investigate the effects of bisphenol A (BPA), an estrogen-like environmental endocrine disrupter, on the placental function and reproduction in rats. The mRNA levels of the placental prolactin-growth hormone(PRL-GH) gene family, placental trophoblast cell frequency and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats ($160g{\pm}20g$) were detected by the presence of the copulatory plug or sperm in the vaginal smear, which marked Day 0 of pregnancy. Pregnant rats were divided into three groups. The control group was intraperitoneally injected with a sesame oil vehicle. The two remaining groups were injected with 50 or 500 mg/kg B.W/day of BPA, resuspended in sesame oil, on either days 7 to 11 or 16 to 20 of pregnancy, with the rats sacrificed on either day 11 or 20, respectively. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction. The hormone concentrations were analyzed by radioimmunoassay, and the frequency of the placental trophoblast cells observed by a histochemical study. Reproductive data, such as the placental weight and litter size, were surveyed on day 20. The fetal weight was surveyed for 4 weeks after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the PRL-GH gene family, such as placental lactogen I, Iv and II, prolactin like protein A, C and Cv, and decidual prolactin-related protein were significantly reduced due to BPA exposure. The mRNA levels of the Pit-1a and b isotype genes, which induce the expression of the PRL-GH gene family in the rat placenta, were also reduced due to BPA exposure. The PL-Iv and PL-II concentrations were reduced in the BPA exposed group. During the middle to last stage of pregnancy (Days 11-20), a high dose of BPA exposure reduced the frequency of spongiotrophoblast cells, which are responsible for the secretion of the PRL-GH hormones. Reproductive data, such as the placental and fetal weights and the litter size, were reduced, but that of the pregnancy period was extended in the BPA exposed compared to the control group. Conclusions : BPA disrupts the placental functions in rats, which leads to reproductive disorders.