• Fisheries and Aquatic Sciences
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• v.24 no.10
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• pp.330-339
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• 2021

Oyster (Crassostrea gigas) is a marine bivalve mollusk widely distributed in coastal areas, and have been long widely used in industrial resources. Several studies demonstrated that fermented oyster (FO) extract attribute to bone health, but whether administration of FO play as an endocrine disruptor has not been studied. Therefore, in the present study, we investigated the effect of FO on the endocrine system in vitro and in vivo. As the results of the competitive estrogen receptor (ER) and androgen receptor (AR) binding affinities, FO was not combined with ER-α, ER-β, and AR. However, 17β-estradiol and testosterone, used as positive control, were interacted with ER and AR, respectively. Meanwhile, oral administration of 100 mg/kg and 200 mg/kg of FO doesn't have any harmful effect on the body weight, androgen-dependent sex accessory organs, estrogen-dependent-sex accessory organs, kidney, and liver in immature rats. In addition, FO supplementation has no effect on the serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone, and 17β-estradiol. However, the relative weight of androgen- and estrogen-dependent organs were significantly increased by subcutaneously injection of 4.0 mg/kg of testosterone propionate (TP) and by orally administration of 1.0 ㎍ of 17α-ethynyl estradiol (EE) in immature male and female rats, respectively. Furthermore, TP and EE administration markedly decreased the serum LH and FSH levels, which are similar those of mature Sprague-Dawley (SD) rat. Furthermore, the testosterone and 17β-estradiol levels were significantly enhanced in TP and EE-treated immature rats. Taken together, our findings showed that FO does not interact with ER and AR, suggesting consequentially FO does not play as a ligand for ER and AR. Furthermore, oral administration of FO did not act as an endocrine disruptor including androgenic activity, estrogenic activity, and abnormal levels of sex hormone, indicating FO may ensure the safety on endocrine system to develop dietary supplement for bone health.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.269-275
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• 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 Life Science
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• v.33 no.9
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• pp.693-702
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• 2023

The present study examined the rate of cell growth and differentiation potential into adipocytes in A549 lung adenocarcinoma cells exposed to each adipogenic medium containing glucose metabolism hormones, such as thyroxine (T4) thyroid hormone and glucocorticoid (GC) adrenal steroid hormone, as well as pioglitazone (PGZ), a PPARγ agonist. Following each adipogenic treatment for 2 weeks, the rate of cell growth was significantly (p<0.05) inhibited, and the level of telomerase activity was significantly (p<0.05) decreased in the PGZ-based adipogenic medium containing both T4 and GC hormone compared with those containing each T4 or GC hormone. Moreover, the adiposome-like vesicles were highly reacted with Oil-Red O staining solution, and the levels of transcripts expressed in the differentiating adipocytes for adipogenesis, including adinopectin, leptin, and resistin, were significantly (p<0.05) increased in the PGZ-based adipogenic medium containing both T4 and GC hormone compared with those of the adipogenic medium containing each T4 or GC hormone, implying that adipocytic differentiation has fully occurred in the A549 cancer cells. Based on present observations, the PGZ-based adipogenic medium containing both T4 and GC efficiently induces inhibition of cell growth and cellular differentiation into adipocytes in A549 cancer cells rather than in the adipogenic medium containing only T4 or GC hormone. Adipogenic treatment could provide potential probability in cancer chemotherapy.

• The Journal of Korean Medicine
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• v.22 no.4
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• pp.1-9
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• 2001

Objectives : To investigate the effect of Taxilli Ramulus (TR) extract on bone metabolism of ethanol-treated animal model. Methods : The changes of serum calcium, calcitonin, estrogen level, a1ka1ine phosphatase activity, osteocalcin, parathyroid hormone content and urine calcium level were observed with ethanol treatment for 60 days. The results were compared with an ethanol- TR extract double treatment group. Results : We observed increment of serum osteocalcin, parathyroid hormone content, alkaline phosphatase activity and urine calcium level by chronic ethanol feed and they were recovered to near normal level with Taxilli Ramulus extract treatment. Weight gain, serum calcium level, calcitonin and estrogen content were remarkably reduced with ethanol treatment and their levels were normalized by Taxilli Ramulus extract. Conclusions : These results showed that Taxilli Ramulus extract have the ability to recover to normal in the body an abnormal calcium metabolism process due to external factors. These results suggested that Taxilli Ramulus extract have preventive effects on calcium concentration loss and osteoporosis.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.455-460
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• 1998

The present study was aimed at investigating whether the development of hypertension is related with an altered expression of nitric oxide synthases (NOS) in the kidney. By Western blot analysis, the expression of bNOS and ecNOS isoforms was determined in the kidney of deoxycorticosterone acetate (DOCA)-salt and two-kidney, one clip (2K1C) rats. In DOCA-salt hypertension, the expression of both bNOS and ecNOS was decreased, along with tissue contents of nitrites. In 2K1C hypertension, the nitrite content of the clipped kidney was decreased along with ecNOS levels, whereas neither the nitrite content nor the expression of NOS isoforms was significantly altered in the contralateral non-clipped kidney. These results suggest that the development of hypertension is associated with an altered renal expression of NOS and nitric oxide generation in DOCA-salt and 2K1C rats.

• Journal of Plant Biology
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• v.38 no.4
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• pp.337-341
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• 1995

Hairy roots of Korean ballon flower (Platycodon grandiflorum A. DC) were induced from the root tissues infected with Agrobacterium rhizogenes ATCC 15834. Growth and polyacetylene [lobetyol (1), lobetyolin (2) and lobetyolinin (3)] production fo ten hairy root clones cultured in 1/4 Gamborg B5 (B5) liquid medium were determined. One selected hairy root clone (D6) grew well in hormone free-B5 liquid medium and showed maximum content of polyacetylenes at week 6 for 1 (0.375% dry wt) and at week 7 for 2 and 3 (3.030% and 0.206% dry wt, respectively) whose levels were much higher than those of the intact plant root (1:0.019%, 2:0.077% dry wt, 3 was not detected).

• Clinical and Experimental Pediatrics
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• v.55 no.1
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• pp.6-10
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• 2012

Human puberty is a complex, coordinated biological process with multiple levels of regulations. The timing of puberty varies greatly in children and is influenced by both environmental and genetic factors. The key genes of pubertal onset, $KISS1$, $GPR54$, $GNRH1$ and $GNRHR$, may be major causal factors underlying gonadotropin-releasing hormone-dependent precocious puberty (GDPP). Two gain-of-function mutations in $KISS1$ and $GPR54$ have been identified recently as genetic causes of GDPP. $GNRH1$ and $GNRHR$ are also gene candidates for GDPP; however no mutations have been identified in these genes. Presently potential genetic causes like $LIN28B$ continues to appear; many areas of research await exploration in this context. In this review, I focus primarily on the genetic causes of GDPP.

• Journal of Digestive Cancer Research
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• v.3 no.1
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• pp.21-25
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• 2015

Gastric neuroendocrine tumors (GNETs, also known as gastric carcinoids) are rare form of hormone-secreting neoplasms that present with varied clinical syndromes. There are four types of GNETs based on size, proliferation, localization, differentiation, and hormone production. Type I GNET is related to autoimmune atrophic gastritis and hypergastrinemia. Type II GNETs are related to multiple endocrine neoplasia (MEN)-1, Zollinger-Ellison syndrome and hypergastrinemia. Type 3 GNETs are not associated with any background pathology, and type 4 GNETs are poorly differentiated tumors. The most useful diagnostic and prognostic marker for gastrointestinal NETs is plasma chromogranin A (CgA) levels. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. For optimal management, the type, biology, and stage of the tumor must be considered. Here, we provide a comprehensive and up-to-date review of GNETs.

• IMMUNE NETWORK
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• v.4 no.1
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• pp.60-64
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• 2004

Background: Microglial cells, major immune effector cells in the central nervous system, become activated in neurodegenerative disorders. Activated microglial cells produce proinflammatory mediators such as nitric oxide (NO), tumor necrosis factor-$\alpha$ and interleukin-$1{\beta}$(IL-$1{\beta}$). These proinflammatory mediators have been shown to be significantly increased in the neurodegenerative disorders such as Alzhimer's disease and Pakinson's disease. It was known that one of the neurodegeneration source is stress and it is important to elucidate mechanisms of the stress response for understanding the stress-related disorders and developing improved treatments. Because one of the neuropeptide which plays a main role in regulating the stress response is corticotropin-releasing hormone (CRH), we analyzed the regulation of NO release by CRH in BV2 murine microglial cell as macrophage in the brain. Methods: First, we tested the CRH receptor expression in the mRNA levels by RT-PCR. To test the regulation of NO release by CRH, cells were treated with CRH and then NO release was measured by Griess reagent assay. Results: Our study demonstrated that CRH receptor 1 was expressed in BV2 murine microglial cells and CRH treatment enhanced NO production. Furthermore, additive effects of lipopolysaccaride (LPS) and CRH were confirmed in NO production time dependantly. Conclusion: Taken together, these data indicated that CRH is an important mediator to regulate NO release on microglial cells in the brain during stress.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.411-416
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• 1993

We assessed effects of ovine luteinizing hormone (oLH) and follicle-stimulating hormone (oFSH) on the granulose and theca layers from the four largest follicles, $F_1-F_4$ of hens which had been hypophysectomized 12 h before expected ovulation. Ovine LH (0.4 mg), oFSH (0.4 mg) or oLH in combination with oFSH (0.4 mg each) was injected intravenously 6 h after hypophysectomy. Progesterone, testosterone and $estradiol-17{\beta}$ levels of the granulose and theca layers which were removed 6 h after hormone injection, were measured by radioimmunoassay. Progesterone contents of $F_1-F_3$ granulosa layer at 12 h after hypophysectomy were much lower than those of control hens. This reduced progesterone level was restored partially by the injection of oLH alone for $F_1$, while no follicles responded to oFSH treatment. In contrast, the injection of oLH in combination with oFSH resulted in high progesterone content of the granulose layer from all four follicles. Progesterone content of the theca layer was negligible in all treatments. Simultaneous injection of oLH and oFSH also elevated $estradiol-17{\beta}$ level accumulating in the theca layer from all follicles, of which much higher concentrations of $estradiol-17{\beta}$ were observed when comparison were made to each of their corresponding controls. No appreciable change in testosterone contents of two layers was observed in the present experiments. These results suggest that oFSH augments function of oLH to stimulate the production of progesterone in the granulose layer and $estradiol-17{\beta}$ in the theca layer.