• Korean Journal of Biological Psychiatry
• /
• v.10 no.1
• /
• pp.62-69
• /
• 2003

Corticotropin-releasing factor(CRF) and neuropeptide Y(NPY) are known to play important roles in mediating stress responses and stress-related behavior. To elucidate the role of neuropeptides in response to the condition that had paired with traumatic event, we observed the changes of CRF and NPY by immunohistochemistry using a conditioned footshock paradigm. Male Sprague-Dawley rats were placed in a shuttle box and exposed to 20 pairings of a tone(< 70dB, 5sec) followed by a footshock(FS, 0.8mA, 1sec) over 60min. A second group was exposed to the tone-footshock pairings, returned to the homecage for 2days, and then reexposed to the test chamber and 20tones alone for 60min, prior to sacrifice. Control groups were : a) sacrificed without exposure to FS ; b) exposed to the tone-footshock pairings and then sacrificed two days later ; or c) exposed to the chamber and tones alone, returned to the homecage for 2days and then reexposed to the chamber and 20tones over 60min prior to sacrifice. CRF was increased in animals exposed to FS or the aversive condition(context and tone) that had paired to FS in bed nucleus of the stria terminalis (BNST) compared to the control. NPY was increased by FS in amygdala and PVN, but the condition previously associated with FS results in slight increase only in amygdala area. These results suggest that the BNST appears to be the mostly involved neural circuit in response to explicit cues previously paired with footshock. Moreover, this study raise the possibility that increased CRF peptide in the BNST in response to re-exposure to the aversive condition may underlie, in part, the experience of conditioned fear-related anxiety behavior.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.2
• /
• pp.244-251
• /
• 1997

The relationship between structure and biological activity was studied on the three neuropeptides (mammalian, trout- and goldfish-neuropeptide $\gamma$) that were syntheized by the solid-phase method. Circular dichroism spectra showed that mammalian, trout- and goldfish-neuropeptide $\gamma$ adopted an unordered structure in buffer solution. In the-presence of neutral and acidic liposomes, mammalian and trout-neuropeptioe $\gamma$ also took a random structure. However, goldfish-neuropeptide $\gamma$ took an $\alpha-helical$ structure in acidic liposomes. The intestinal motility response was investigated with carp intestines, guinea-pig ileums and rat duodenums. In case of carp intestine, contractile activity was as follows : goldfish-neuropeptide $\gamma\simeq$ trout-neuropeptide $\gamma>$ mammalian-neuropeptide $\gamma$, On the other hand, the contractile activity of mammalian-neuropeptide $\gamma$ was more potent than trout- and goldfish-neuropeptide $\gamma$ in the guinea-pig ileums and rat duodenums. These results suggest that neuropeptide $\gamma$ show the species-specific activity.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.8
• /
• pp.5336-5342
• /
• 2015

Although demand for scar treatment has been rising as our quality of life is improved, most scar treatment products rely on importation. Enkephalin is one of the neuropeptides secreted from neuronal ends. As both skin and neuron are derived from the exoderm during the development process, skin cells express opioid receptors as neuronal cells do. Opioid receptors are categorized into three types, mu(m)-, delta(d)-, and kappa(k)- opioid receptors, all of which are directly involved in the wound healing process. In this study, enkephalin derivatives are synthesized by Alanin Scan and their efficacy was evaluated and compared. In vitro wound healing effects, stimulatory effects of collagen synthesis, and skin hydration effects were also evaluated and confirmed. Among Enkephalin derivatives, AS13 showed highest wound healing effect.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.3
• /
• pp.148-152
• /
• 2005

A novel neuropeptide with a relaxing activity on the dorsal retractor muscle (DRM) was isolated from the whole body extract of the starfish, Asterina pectinifera. The peptide was purified by gel-filtration ion-exchange and $C_{18}$ reversed-phase HPLC. The complete amino acid sequence of this peptide, which was determined by automated Edman degradation and MALDI-TOF mass, was Phe-Gly-Lys-Gly-Gly-Ala-Tyr-Asp-Pro-Leu-Ser-Ala-Gly-Phe-Thr-Asp. A comparison of the amino acid sequence with those of other known neuropeptides revealed that the asteripectin was a novel neuropeptide with smooth muscle-relaxing activity on the starfish DRM. This peptide showed threshold response to relaxing activity on the DRM at $10^{-10}M$ and the maximal relaxing effect was $120{\pn}7.0\%$ at $10^{-5}M$. The relaxing activity of this peptide on the starfish DRM increased in a dose-dependent manner.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.3
• /
• 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 the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7575-7581
• /
• 2015

Corticotropin-releasing factor(CRF), one of the stress driven neuropeptides, was widely proposed to influence hair loss and re-growth. For the development of receptor antagonists, the screening system based on intracellular calcium signal process was developed and optimized. The aequorin parental cells were transfected with CRF1 receptor and alpha 16 promiscuous G protein cDNA to establish HEK293a16/hCRF1, a stable cell line for the human CRF1 receptor. In HEK293a16/hCRF1 cells, the range of sauvagine dose response was 12-fold higher($EC_{50}:15.21{\pm}1.83nM$) than in the transiently expressed cells, hence essential conditions for the antagonist screening experiments such as the robust signals and high solvent tolerance were secured. The standard antagonists for the CRF1 receptor, antalarmin and CP154526, resulted $IC_{50}$ values of $414.1{\pm}5.5$ and $290.7{\pm}1.9nM$, respectively. Similar results were presented with frozen HEK293a16/hCRF1 cells. Finally, our HEK293a16/hCRF1 cells with the aequorin based cellular functional assay can be a model system for the development of functional cosmetics and modulators that can have a clinical efficacy on hair re-growth.

• Journal of Life Science
• /
• v.22 no.4
• /
• pp.499-507
• /
• 2012

Previous work has characterized myomodulin A (MMA, PMSMLRLamide) and myomodulin E (MME, GLQMLRLamide) purified from the central nervous systems of the sea hare, $Aplysia$ $Kurodai$, using the anterior byssus retractor muscle (ABRM) of the mussel, $Mytilus$ $edulis$. The amino acid sequences of MMA and MME were the same as those of the myomodulin family peptide found in other mollusks. In this study, we synthesized MME, its derivatives, and other neuropeptides to investigate the relationship between the structure and biological activity of MME. The primary structures of MME's derivatives, Des[$Gly^1$]-MME, Des[$Gly^1,Leu^2$]-MME, and Des[$Gly^1,Leu^2,Gln^3$]-MME, were LQMLRLamide, QMLRLamide, and MLRLamide, respectively. MMA and synthetic peptides were tested on ABRM in $M.$ $edulis$ as well as muscle preparations in $Achatina$ $fulica$. MME displayed an inhibitory effect on phasic contraction of the ABRM at $1{\times}10^{-9}$ M or higher. MME also had a relaxing effect on the catch-tension of AMRM at $1{\times}10^{-8}$ M. Both MMA and its analogs stimulated a contractile response on the crop and relaxed the catch-relaxing response on the penial retractor muscle of $A.$ $fulica$. These results suggest that MME and its analogs have modulatory effects on various muscles of mollusks. This study has also laid the groundwork for future neural and circuit modulation studies during animal behavioral changes.

• The Korean Journal of Pharmacology
• /
• v.31 no.1 s.57
• /
• pp.11-15
• /
• 1995

Serotonergic neurons in medulla oblongata play an important role in the endogenous descending pain inhibitory system. To illucidate the factors involved in the regulation of medullary serotonergic neurons, we studied the effects of cholecystokinin (CCK) and agents acting on various second messenger systems on 5-hydroxytryptamine (5-HT) release from cultured neurons of rat fetal (gestational age 14th day) medulla oblongata. Cultured cells maintained for 10 days in vitro were stimulated for 48 hours with CCK or other neuropeptides at 10 micromolar concentration. CCK ($10{\mu}M$) and substance P ($10{\mu}M$) significantly increased. 5-HT release. However, somatostatin, proctolin, thyrotropin releasing hormone, and interleukin-6 did not have any effects on 5-HT release. Nimodipine ($1{\mu}M$), a calcium channel blocker, almost completely, and calmidazolium ($1{\mu}M$), a calmodulin antagonist, significantly inhibited the CCK-induced 5-HT release. The total 5-HT content (intracellular 5-HT plus released 5-HT) was significantly increased by CCK. However, the intracellular 5-HT content was not significantly changed by CCK. Forskolin ($5{\mu}M$), an adenylate cyclase activiator, but not $2{\mu}M$ phorbol myristate acetate (PMA), a protein kinase C activator, significantly enhanced 5-HT release. The total 5-HT content (intracellular 5-HT plus released 5-HT) was significantly increased by forskolin. However, the intracellular 5-HT content was not significantly changed by forskolin. PMA had no effect on intracellular 5-HT levels. These results suggest that CCK regulates serotonergic neurons in the medulla oblongata by enhancing 5-HT secretion through calcium influx and caimodulin, and that cyclic AMP system but not protein kinase C system is involved in 5-HT release.

• Clinical and Experimental Pediatrics
• /
• v.49 no.5
• /
• pp.533-538
• /
• 2006

Purpose : The headache, one of the symptoms of meningitis, is related to abrupt elevation of intracranial pressure(ICP) or stimulation of intracranial nociceptive structure. However, in cases of mild elevation of ICP or normal findings of cerebrospinal fluid(CSF) analysis, patients sometimes complain of headaches. Therefore, other pathways may contribute to the occurrence of headaches in aseptic meningitis or meningismus. We intend to investigate the role of substance P(SP) and calcitonin gene-related peptide(CGRP) in aseptic meningitis or meningismus. Methods : We measured leukocyte count, the concentration of protein and glucose in CSF and ICP of patients with meningeal irritation sign. We also measured SP and CGRP levels by using immunoassay. We analyzed the relationship between the presence of headache and the value of SP and CGRP. Results : The concentrations of CGRP($18.8{\pm}10.5ng/mL$) in CSF and ICP($14.8{\pm}4.5cmH_2O$) in aseptic meningitis group were significantly higher than in those($14.1{\pm}7.4ng/mL$ and $12.0{\pm}5.1cmH_2O$, respectively) of the meningismus group(P<0.05). There was no significant difference in the SP levels between the two groups. In the aseptic meningitis group, the concentrations of SP and CGRP were significantly higher in the normal ICP group than in the elevated ICP group(P<0.05). Conclusion : Headaches in children with aseptic meningitis or meningismus is considered to be related to the elevation of the CSF levels of SP and CGRP.

• The Korean Journal of Pharmacology
• /
• v.29 no.2
• /
• pp.225-235
• /
• 1993

Pituitary LH release has been known to be regulated by the hypothalamic gonadotropin releasing hormone (GnRH) and the gonadal steroid hormones. In addition, neurotransmitters and neuropeptides are actively involved in the control of LH secretion. The alteration in LH release might reflect changes in biosynthesis and/or posttranslational processing of LH. However, little is known about the mechanism by which biosynthesis of LH subunits is regulated, especially at the level of transcription. In order to investigate if ovarian steroid hormones regulate the LH subunit gene expression, ${\alpha}\;and\;LH{\beta}$ steady state mRNA levels were determined in anterior pituitaries of ovariectomized rats. Serum LH concentrations and pituitary LH concentrations were increased markedly with time after ovariectomy. ${\alpha}\;and\;LH{\beta}$ subunit mRNA levels after ovariectomy were increased in a parallel manner with serum LH concentrations and pituitary LH contents, the rise in $LH{\beta}$ subunit mRNA levels being more prominent than the rise in ${\alpha}\;subunit$ mRNA. ${\alpha}\;and\;LH{\beta}$ subunit mRNA levels in ovariectomized rats were negatively regulated by the continuous treatment of ovarian steriod hormones for $1{\sim}4\;days$ and $LH{\beta}\;subunit$ mRNA seemed to be more sensitive to negative feedback of estradiol than progesterone. Treatment of estrogen antagonist, LY117018 or progesterone antagonist, RU486 significantly restroed LH subunit mRNA levels as well as LH release which were suppressed by estradiol or progesterone treatment. These results suggest that ovarian steroids negatively regulate the LH synthesis at the pretranslational level by modulating the steady state levels of ${\alpha}\;and\;LH{\beta}\;subunit$ mRNA and $LH{\beta}\;subunit$ mRNA seemed to be more sensitive to negative feedback action of estradiol than progesterone.