• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.1-6
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• 1990

We established an in vitro system of central serotonergic neurons by culturing dissociated rat embryonic (El4) brainstem cells to 14 days in vitro and monitored the serotonergic neuronal growth by measuring 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) contents in the cells with hish performance liquid chromatography with electrochemical detection (HPLC-EC). We studied also tile effects of various drugs on the contents of 5-HT and 5-HIAA, confirming in vivo reports. The 5-HT content (13 ng/mg protein) and 5-HT turnover rate (17 pmol/mg protein/h) at 14 days in vitro were in good agreement with those reported in the adult rat brain. The 5-HT content was more easily depleted with p-chlorophenylalanine, a tryptophan hydroxylase inhibitor than with NSD 1015 (3-hydroxybenzylhydrazine), an aromatic L-amino acid decarboxylase (AADC) inhibitor. Incubation of the cultures with tryptophan or 5-hydroxytryptophan increased the rate of serotonin formation implying that neither tryptophan hydroxylase nor AADC is saturated with its amino acid substrate in this in vitro system . The 5-HT content was depleted by reserpine. The 5-HT and 5-HIAA contents were increased and decreased, respectively, by monoamine oxidase inhibitors. All the above results indicate that the biochemical properties of the central serotonergic neurons in this culture system reflect reliably those of central serotonergic neurons in vivo. We suggest that measuring 5-HT and 5-HIAA contents in the primary cultured dissociated brainstem-cells with HPLC-EC is useful in the study of pharmacology as well as toxicolgy of the central serotonergic neurons.

• Korean Journal of Biological Psychiatry
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• v.11 no.2
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• pp.146-154
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• 2004

Objective:Attention deficit hyperactivity disorder(ADHD) is the most common childhood psychiatric disorder, affecting 3-5% of school-aged children. Although the biological basis of ADHD is unknown, family studies provide strong evidence that ADHD has a genetic basis. Recent genetic studies have suggested associations between ADHD and serotonin 1B(5HT1B) receptor gene G861C polymorphism. The aim of this study is to test for the association between ADHD and 5HT1B receptor gene G861C polymorphism in Korean population. Method:We processed DNA extraction and genotyping. 106 Korean children with ADHD and their parents were analyzed using the transmission disequilibrium test(TDT) and haplotype-based haplotype relative risk (HHRR). And the ADHD children were compared with 212 age and gender matched normal controls. Results:There was no statistical difference of distributions between ADHD cases and controls. We did not observe any preferential transmission of alleles of 5HT1B receptor gene G861C polymorphism in ADHD. Conclusions:Though there is the possibility of failing to detect small genetic effects, our results show no evidence of an association between ADHD and 5HT1B receptor gene G861C polymorphism in the Korean population and indicate that it is unlikely that the 5HT1B receptor is implicated in the susceptibility to ADHD.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.6
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• pp.295-301
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• 2003

Striatum plays a crucial role in the movement control and habitual learning. It receives an information from wide area of cerebral cortex as well as an extensive serotonergic (5-hydroxytryptamine, 5-HT) input from raphe nuclei. In the present study, the effects of 5-HT to modulate synaptic transmission were studied in the rat corticostriatal brain slice using in vitro extracellular recording technique. Synaptic responses were evoked by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. 5-HT reversibly inhibited coticostriatal glutamatergic synaptic transmission in a dose-dependent fashion (5, 10, 50, and $10{\mu}M$), maximally reducing in the corticostriatal population spike (PS) amplitude to $40.1{\pm}5.0$% at a concentration of $50{\mu}M$ 5-HT. PSs mediated by non-NMDA glutamate receptors, which were isolated by bath application of the NMDA receptor antagonist, d,l-2-amino-5-phospohonovaleric acid (AP-V), were decreased by application of $50{\mu}M$ 5-HT. However, PSs mediated by NMDA receptors, that were activated by application of zero $Mg^{2+}$ aCSF, were not significantly affected by $50{\mu}M$ 5-HT. To test whether the corticostriatal synaptic inhibitions by 5-HT might involve a change in the probability of neurotransmitter release from presynaptic nerve terminals, we measured the paired-pulse ratio (PPR) evoked by 2 identical pulses (50 ms interpulse interval), and found that PPR was increased ($33.4{\pm}5.2$%) by 5-HT, reflecting decreased neurotransmitter releasing probability. These results suggest that 5-HT may decrease neurotransmitter release probability of glutamatergic corticostriatal synapse and may be able to selectively decrease non-NMDA glutamate receptor-mediated synaptic transmission.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.2
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• pp.165-178
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• 2001

In order to elucidate the biological etiology and the relationship between the ontogenesis of serotonin system and psychopathology in ADHD, plasma serotonin(5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid(5-HIAA) were measured and the correlation between the plasma levels of 5-HT and 5-HIAA and age were evaluated in 46 ADHD patients and 18 control subjects. The ADHD patients were composed of 16 combined type, 10 inattentive type, and 20 hyperactive-impulsive type and the control subjects were communication disorders. The results are summarized as follows：1) There was significant difference in plasma 5-HT levels among combined, inattentive and hyperactive-impulsive and control subjects(ANOVA F=4.33, df 3, 60, p<0.05), and post-hoc test using Scheffe method showed significant difference between the combined type and control group. But, post-hoc tests showed no significant differences between combined and inattentive, combined and hyperactive-impulsive, hyperactive-impulsive and inattentive, hyperactive-impulsive and control and inattentive and control groups. 2) There was no significant differences in plasma 5-HIAA levels among the combined, hyperactive- impulsive, inattentive and control groups(ANOVA F=2.08, df 3, 60, p>0.05). 3) Significant difference in 5-HT level was found between the whole ADHD group(N=46) and the control group(N=18)(T=3.10, df 62, p<0.05). But no significant difference in 5-HIAA level was found between the whole ADHD group and the control group(T=1.90, df 62, p>0.05). 4) Plasma 5-HT and 5-HIAA levels showed no significant correlation with TOVA findings(5-HT：omission pearson correlation 0.10, commision 0.23, reaction time 0.01, variability in attention 0.11, all p>0.05, 5-HIAA：omission 0.21, commision 0.15, reaction time 0.09, variability in attention 0.15, all p>0.05). 5) Plasma 5-HT and 5-HIAA levels showed no significant correlation with attention, hyperactivity and impulsivity based on DSM-IV criteria. 6) Plasma 5-HT and 5-HIAA levels showed no significant correlation with age both in ADHD and control group. These findings show that decreased plasma 5-HT level may play a role in the genesis of ADHD, but this finding has no significant correlation with the psychopathology of ADHD. And we could not find any significant differences in ontogenetic processes in 5-HT. Future studies should be focused on the drug effects, family history and prognosis based on the biochemical subtypes(high and low 5-HT group).

• Development and Reproduction
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• v.6 no.2
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• pp.111-115
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• 2002

5-Hydroxytryptamine(5-HT; serotonin) system has been implicated in the modulation of male sexual behaviors and the secretion of reproductive hormones. In human males, selective serotonin re-uptake inhibitors(SSRIs) are known to improve the major male sexual dysfunction, premature ejaculation, through the central nervous system-mediated pathways. As numerous hormone and local factors, 5-HT may have peripheral role in the regulation of male sexual function. The expression of 5-HT receptor subtypes in the target tissue, however, has not been explored yet. The present study was undertaken to test whether the 5-HT receptor subtypes are expressed in the reproductive tissues of male rat, especially in ejaculatory machinery such as seminal vesicle and vas deferens. To do this, reverse transcription-polymerase chain reaction(RT-PCR) and Southern blot analysis were employed. The transcripts for the 1A, 1B and 2C subtypes of 5-HT receptor were amplified in all the tested tissues. The present study demonstrated the expression of 5-HT receptor in the rat ejaculatory machinery, suggesting that 5-HT may play a pivotal role in the male sexual function via not only central pathway but also peripheral route. Further study on the receptor subtype-specific effect and their harmonized mode of action will be needed to establish the understanding of ejaculation mechanism and drug design.

• Toxicological Research
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• v.13 no.4
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• pp.359-365
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• 1997

Many factors are known to be responsible for cerebral ischemic injury, such as excitatory neurotransmitters, increased intraneuronal calcium, or disturbance of cellular energy metabolism. Recently, oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of ischemia/reperfusion injury. Therefore, to investigate the role of oxygen free radical during ischemia/reperfusion, in the present study the effect of endogenous oxygen free radical scavenger, superoxide dismutase / catalase(SOD / catalase) on the release of [$^3$H]-5-hydroxytryptamine([$^3$H]-5-HT) during hypoxia/reoxygenation in rat hippocampal slices was measured. The hippocampus was obtained from the rat brain and sliced 400 gm thickness with manual chopper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing [$^3$H]-5-HT(0.1 $\mu$M, 74 $\mu$Ci) for uptake, and washed. To measure the release of [$^3$H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Induction of hypoxia for 20 min (gassing it with 95% N$_2$/5% CO$_2$) was done in the 6th and 7th tube, and oxygen free radical scavenger, SOD / catalase was added 10 minutes prior to induction of hypoxia. The radioactivity in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. When slices were exposed to hypoxia for 20 min, [$^3$H]-5-HT release was markedly decreased and a rebound release of [$^3$H]-5-HT was observed on the post-hypoxic reoxygenation period. SOD / catalase did not changed the release of [$^3$H]-5-HT in control group, but inhibited the decrease of [$^3$H]-5-HT release in hypoxic period and rebound increase of [$^3$H]-5-HT in reoxygenation period. This result suggest that superoxide anion may play a role in the hypoxic-, and reoxygenation-induced change of [$^3$H]-5-HT release in rat hippocampal slices.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.59-59
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• 2003

Serotonin (5-HT; 5-hydroxytryptamine) exerts multiple effects on central nervous system as well as behaviors such as mood and appetite. The signaling of serotonin is mediated by 7 families of serotonin receptors, designated 5-HT$_1$ to 5-HT$_{7}$. Six families of this receptor are G-protein coupled 7TM receptors, and the third intracellular loop of these receptors is proposed to interact with specific types of G-proteins. To investigate the specific interaction between the third intracellular loop of 5-HT$_{6}$ with G$\square$s, we have constructed a chimera protein that represent the third intracellular loop of 5-HT$_{6}$ within a leucine zipper motifs, In addition an alpha subunit of human G-protein that interact with 5-HT$_{6}$ was cloned into a bacterial expression vector. The two proteins were expressed in E. coli and purified in homogeneity. The interaction of the prepared proteins was examined by ELISA assay. The affinity between the two proteins and effect of insertion mutations were discussed.ussed.d.

• Korean Journal of Acupuncture
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• v.25 no.1
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• pp.229-246
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• 2008

Objectives : Acupoints of LR1(Dadun)${\cdot}$HT9(Shaochong), KI10(Yingu)${\cdot}$HT3(Shaohai) are used as controlling the diseases from heart problems. Especially, when they are used, tonification or sedation techniques method is taken as a controlling the medication for an early stroke in the Korean medicine. So the aim of this study is to investigate the anti-apoptotic and neuroprotective effects of Acupuncture techniques of tonification or sedation at LR1${\cdot}$HT9, KI10${\cdot}$HT3 on the focal ischemia induced by intraluminal filament insertion in rats. Materials and Methods : The focal ischemia was induced by intraluminal filament insertion into middle cerebral artery. The animals were divided into five groups (n=7 in each group) : Control group, no therapy group after ischemia induced; AT-1; acupuncture therapy group at LR1${\cdot}$HT9, KI10${\cdot}$HT3 after ischemia-induced. AT-2; acupuncture therapy at right LR1, HT9(forward direction), KI10${\cdot}$HT3(opposite direction) inserting to the direction of route of the each meridian. AT3; acupuncture therapy at right LR1, HT9(twirling forward with the thumb of right hand 9 times), KI10${\cdot}$HT3(twirling forward with the forefinger of right hand 6 times) AT-4; acupuncture therapy at right LR1, HT9(forward direction, twirling forward with the thumb of right hand 9 times), KI10${\cdot}$HT3(opposite direction, twirling forward with the forefinger of right hand 6 times) inserting to the direction of route of the each meridian. The anti-apoptotic and neuroprotective effects of Acupuncture techniques of tonification or sedation at LR1, HT9, KI10${\cdot}$HT3 were observed by Bax, Bcl-2, mGluR5, Cytochrome c, Cresyl violet and ChAT-stain. Results : The intensity of Bax and Bax/Bcl-2 ratio were increased in ACU-2 and ACU-4 group but decreased in ACU-3 group. The intensity of mGluR5 was increased in ACU-1, ACU-2, ACU-3 and ACU-4 group. The intensity of cytochrome c was decreased in ACU-3 and ACU-4 group. The density of neurons stained by Cresyl violet and ChAT were increased in ACU-1, ACU-3 and ACU-4 group. Conclusions : Our study suggests that acupuncture therapy of tonification at LR1, HT9 by twirling forward with the thumb of right hand 9times, sedation at KI10${\cdot}$HT3 by twirling forward with the forefinger of right hand 6 times after perpendicularly inserting needle shows anti-apoptotic and neuroprotective effects on cholinergic neuron in focal cerebral ischemia of the stroke in rats.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.71-82
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• 1966

The inhibitory effect of 5-hydroxytryptamine (5-HT) on the isolated intestinal strips of the tortoise (Amyda japonica), rat, rabbit and guinea pig was investigated. 1) The strips from the middle or lower part of the tortoise intestine responded with relaxation to 5-HT $(10^{-9}{\sim}10^{-5}g/ml)$, and the magnitude of the relaxation was proportional to the dose of 5-HT. The rectal part of the tortoise intestine, in contrast, showed contraction, the magnitude of which also was proportional to the dose of 5-HT. 2) Various blocking agents such as methysergide, morphine, tetracaine, nethalide, bretylium, hexamethonium, mecamylamine and chlorisondamine, showed no selective blocking activity on the relaxant effect of 5-HT on the tortoise intestine. The inhibitory effect of isoproterenol on the tortoise intestine, however, was selectively blocked by nethalide, and the stimulatory effect of 5-HT on the rectal part of the tortoise was blocked by methysergide. 3) In the presence of 5-HT, the stimulatory effect of DMPP on the tortoise intestine was remarkably attenuated, whereas that of acetylcholine and $BaCl_2$ was little affected. In the presence of isoproterenol, the stimulatory effect of acetylcholine and $BaCl_2$ were affected, but that of DMPP was little affected. 4) Large dose of 5-HT($10^{-4}$g/ml) produced inhibitory effect on the strips from the distal part of the isolated colon of the rat, rabbit and guinea pig, when the strips had been exposed to 5-HT($10^{-4}$g/ml), methysergide or phen`oxybenzamine. 5) Bretylium, as well as nethalide, abolished or remarkably reduced, in a few cases of the experiments, the inhibitory effect of the large dose of 5-HT on the distal part of the colon, whereas morphine did not affect it. 6) The ileal strips of the guinea pig also showed relaxation, as in the colonic strips, having been exposed to the large dose of 5-HT or phenoxybenzamine. This effect, however, was not obsered in the case of the rabbit ileum. 7) The property of the action-site of 5-HT in the tortoise intestine seemd to be different from the 5-HT receptors which have been revealed by several investigators. 8) Adrenergic component seemed to be participated in the inhibitory effect of 5-HT on the colon of the rat and rabbit.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.308-311
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• 2000

The organic electroluminescene (EL) device has gathered much interested because of its potential in materials and simple device fabrication. We fabricated EL device which have a mixed single emitting layer containing N,N'-diphenyl-N,N'-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine [TPD] and poly(3-hexylthiophene) [P3HT]. The molar ratio between P3HT and TPD chaged with 1:1, 3:1, 5:1, 3:2 and 5:2. EL intensity of ITO/P3HT+TPD/Mg:In devices is enhanced by addition of TPD into P3HT. This can be explained that the energy transfer occurs from TPD to P3HT. Recombination probability increases in emitting layer because that TPD as hole transport material plays a role more injection hole and Mg:In (3.7eV) electrode has low work function make easily electron injection. ITO/P3HT+TPD(5:2)/Mg:In devices emit orange-red light at 28V.