• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.2861-2862
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• 2011

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.315-323
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• 1997

Central tryptaminergic system has been shown to play an important role in the regulation of renal function: $5-HT_1(5-hydroxytryptamine_1)$ receptors might seem to mediate the diuresis and natriuresis, whereas the $5-HT_2\;and\;5-HT_3$ receptors mediate the antidiuretic and antinatriuretic effects. This study attempted to delineate the role of central $5-HT_{1A}$ subtype in the regulation of rabbit renal function by observing the renal effects of intracerebrovent-ricularly(icv)-administered PAPP(p-aminorhenylethyl-m-trifluoromethytphenyl piperazine, LY165163), a selective agonist of $5-HT_{1A}$ receptors. PAPP in doses ranging from 40 to $350{\mu}g/kg$ icv induced significantly diuresis, natriuresis, and kaliuresis, along with increased renal perfusion and glomerular filtration. Systemic blood pressure was also increased. Free water reabsorption$(T^cH_2O)$, a measure of ADH(antidiuretic hormone) secretion, was increased also. Intravenous $350{\mu}g/kg$ of PAPP elicited antidiuresis and antinatriuresis together with decreased blood pressure, thus indicating that the effects of icv PAPP were brought about through the central mechanisms, not by direct peripheral effects of the drug on kidney. Ketanserin, a selective $5-HT_2$ antagonist, $40{\mu}g/kg$ icv, did not affect the renal effects of the icv PAPP. Methysergide, a non-selective $5-HT_1$ antagonist, also did not block the renal functional responses by the icv PAPP. NAN-190, a $5-HT_{1A}$ antagonist, also did not antagonized the renal action of the icv PAPP. However the increased free water reabsorption was abolished by both methysergide or ketanserin pretreatment. The increments of blood pressure by icv PAPP was blocked only by NAN-190 pretreatment. These observations suggest that the central $5-HT_{1A}$ receptor might be involved in the central regulation of rabbit renal function by exerting the diuretic and natriuretic influences.

• Toxicological Research
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• 제12권2호
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• pp.171-179
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• 1996

To investigate the involvement of $5-HT_{2A}/ 5-HT_{2C} receptors in the developmental toxicity of cocaine in rats, mianserin (2.5 mg/kg), a $5-HT_{2A}/5-HT_{2C}$ receptor antagonist, and/or cocaine HCl (45 mg/kg) were administered intraperitoneally (i.p.), during postnatal days (PND) 7-13. Behavioral assessments for the rat pups were done after 100 days of age by using the progressive ratio schedule of reinforcement (FR 1-FR 128, doubled everyday) and cocaine challenge (5, 15 or 30 mg/kg i.p.) upon established FR 32 behavior. Cocaine injected just prior to the FR 32 session suppressed the established FR 32 responding in a dose-dependent manner. The low dose of cocaine did not affect the FR 32 responding, while the high dose of cocaine suppressed it in all experimental groups. However, by the middle dose of cocaine, rats previously received water-cocaine in their early life showed a marked resistance to cocaine-induced behavioral suppression, and this resistance was not observed in rats received both mianserin and cocaine in their early life. These results suggest that $5-HT_{2A}/ 5-HT_{2C}$ receptors may have an important role for the persistently altered behavioral sensitivity to cocaine caused by exposure to cocaine during development.

• 대한약리학회지
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• 제26권2호
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• pp.153-160
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• 1990

5-Hydroxytryptamine(5-HT)를 가토뇌실내로 투여 (icv)하면 이뇨와 Na배설증가가 초래되며, 이러한 작용은 $5-HT_1$ 수용체길항제인 methysergide에 의하여 차단되므로 중추성 신장기능조절에 있어 중추 tryptamine계의 관련이 시사된 바 있다. 본 연구에서는 $5-HT_2$ 길항제로 알려진 ketanserin (KET)를 이용하여 $5-HT_2$ 수용체의 역할을 구명하고자 하였다. KET $120\;{\mu}g(=0.3{\mu}moles)/kg$ icv는 신혈류역학에는 아무런 변동을 일으키지않으나 유의한 Na배설증가를 초래하여, 세뇨관에서의 Na 재흡수 감소가 시사되었다. 전신혈압은 약간 감소하였다. 정맥내 투여시에는 유의한 기능변동을 볼 수 없었다. 5-HT $200{\mu}g/kg$ icv는 경미하나 유의한 Na배설증가 및 이뇨작용을 나타냈다. 그러나 신장기능에 그다지 큰 영향을 미치지 않는 양인 $40{\mu}g/kg$의 KET icv후에는 5-HT의 작용이 크게 강화되어, Na배설분획이 9.3%에 달하였다. Norepinephrine, dopamine, histamine과 같은 다른 생체아민의 신장작용은 KET전처치에 의하여 영향받지 아니하였다. 본 연구는 중추 $5-HT_1$ 수용체와는 반대로 중추 $5-HT_2$ 수용체는 항이뇨 및 Na배설감소를 매개하고 있으며, 중추 tryptamine계는 신장기능을 이중적으로 조절하고 있음을 시사하였다.

• 대한수의학회지
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• 제34권3호
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• pp.447-456
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• 1994

In order to elucidate the characterization of receptors involved in inestinal motility of Israeli carp, spontaneously contracting Israeli carp intestinal preperations were prepared and mounted in the organ chambers for contraction traicings using a polygraph. Various contractile agonists were treated and their dose-response curves were constructed. $EC_{50}$ values$(pD_2)$ of each agonist on specific receptors, $pA_2$ values of competitive antagonists against some agonists, and $K_1$, values of noncompetitive antagonists against some agonists were analyzed for characterization of receptors related with the intestinal contraction. Results obtained through the experiments were summarized as follows: 1. Acetylcholine(ACh) exhibited biphasic dose-response curves: initial ACh-induced dose dependent contractions were observed in pM levels but followed by decreased response in in-between concentration levels. Dose dependent contractions reappeared in ${\mu}M$ level. The peaks in pM and ${\mu}M$ levels appeared in $10^{-13}M$ and $3{\times}10^{-5}M$, respectvely. 2. Carbachol(CaCh) exhibited dose dependent contractions from $10^{-9}M$ to $10^{-5}M$, and its $pD_2$ values were higher than those of ACh($5.60{\pm}0.11$). ACh and CaCh exhibited equiactive contractions. Nicotine had no effects on contractile responses of Israeli carp intestine. 3. ACh-induced responses were inhibited by atropine($K_1:7{\times}10^{-8}M$), a muscarinic antagonist, in a non-competitive manner. But CaCh-induced responses were inhibited by both antimuscarinic atropine($pA_2:9.52{\pm}0.14$) and selective $M_2$ antagonistic 4-DAMP($pA_2:8.16{\pm}0.09$), in competitive manners. Nicotine receptor antagonistic decamethonium and hexamethonium had no effects on ACh-and CaCh-induced contractions. Therefore, the cholinergic receptor related to intestinal motility of Israeli carp was assumed as $M_2$ type. 4. In Israeli carp intestine, 5-HT (serotonin) exhibited dose dependent contractions in concentration range from $10^{-8}M$ to $10^{-5}M$. The maximal responses, however, were corresponded to about 50% of those of ACh or CaCh. 5-HT induced contractions were inhibited by $5-HT_2$ antagonistic ketanserin ($K_1: 7.8{\times}10^{-4}M$) in a non-competitive manner, but not by both of anti $5-HT_1$, spiperone and anti $5-HT_3$, MDL-72222. Hence, $5-HT_2$ receptors are suggested to be existed in Isreli carp intestine.

• The Korean Journal of Physiology and Pharmacology
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• 제25권5호
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• pp.489-494
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• 2021

Oxaliplatin, a third-generation platinum derivative, is the mainstay of current antineoplastic medications for advanced colorectal cancer therapy. However, peripheral neuropathic complications, especially cold allodynia, undermine the life-prolonging outcome of this anti-cancer agent. Rosavin, a phenylpropanoid derived originally from Rhodiola rosea, exhibits a wide range of therapeutic properties. The present study explored whether and how rosavin alleviates oxaliplatin-induced cold hypersensitivity in mice. In the acetone drop test, cold allodynia behavior was observed from days 3 to 5 after a single injection of oxaliplatin (6 mg/kg, i.p.). Cold allodynia was significantly attenuated following rosavin treatment (10 mg/kg, i.p.). Specific endogenous 5-HT depletion by three consecutive pretreatments with parachlorophenylalanine (150 mg/kg/day, i.p.) abolished the analgesic action of rosavin; this effect was not observed following pretreatment with naloxone (opioid receptor antagonist, 10 mg/kg, i.p.). Furthermore, 5-HT_1A receptor antagonist WAY-100635 (0.16 mg/kg, i.p.), but not 5-HT₃ receptor antagonist MDL-72222 (1 mg/kg, i.p.), blocked rosavin-induced analgesia. These results suggest that rosavin may provide a novel approach to alleviate oxaliplatin-induced cold allodynia by recruiting the activity of 5-HT_1A receptors.

• 대한핵의학회지
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• 제31권1호
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• pp.9-18
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• 1997

목 적 : 본 연구에서는 정량적 자가방사선사진법을 이용하여 비정형 항정신병 약물의 하나인 risperidone 이 백서 뇌의 신경수용체에 어떻게 작용하는지를 알아보고자 하였다. 대상 및 방법 : 급성투여군은 백서 30마리를 6군으로 나누어 0, 0.1, 0.25, 0.5, 1, 2mg/kg의 risperidone을 복강내 투여하고 2시간후에 단두하였고, 만성투여군은 0, 0.1, 1mg/kg의 risperidone을 21일간 복강내 투여후 단두하여 정량적자가 방사선사진법으로 $5-HT_2$과 $D_2$ 수용체에 대한 [$^3H$]spiperone 결합을 측정함으로써, 선조체, 측좌핵, 전두엽피질 각각의 $5-HT_2$과 $D_2$ 수용체의 분포변화를 측정하고 투여량에 따른 수용체의 영향을 ANOVA 검정으로 분석하였다. 결 과 : 급성투여군에서 $5-HT_2$ 수용체는 전두엽 피질에서 risperidone 투여후 0.1-2mg/kg의 투여 범위전체에서 [$^3H$]spiperone 결합이 대조군에 비하여 32% 이하로 감소하여 통계적으로 유의한 차이를 보였으며, 선조체와 측좌핵의 피질하 수용체에서는 거의 결합을 보이지 않았다. $D_2$ 수용체는 risperidone 투여량의 증가에 따라 선조체와 측좌핵의 [$^3H$]spiperone 결합이 감소하였으며, 1-2mg/kg의 투여량을 준 경우에는 대조군에 비해 57% 이하로 감소하여 통계적으로 유의한 차이를 보였다. 만성투여군에서는 피질의 $5-HT_2$ 수용체가 대조군에 비하여 저용량투여군과 고용량투여군에서 각각 51%와 46%로 감소하였다. 결론 : Risperidone은 $D_2$ 수용체를 약하게 차단하며 $D_2$ 수용체에 영향을 주는 양보다 적은 양을 투여해도 $5-HT_2$ 수용체를 차단하는 효과를 보임으로써 $5-HT_2$ 수용체에 강력히 작용하는 비정형 항정신병 약물임을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제16권1호
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• pp.65-70
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• 2012

Synaptic long-term potentiation (LTP) and long-term depression (LTD) have been studied as mechanisms of ocular dominance plasticity in the rat visual cortex. Serotonin (5-hydroxytryptamine, 5-HT) inhibits the induction of LTP and LTD during the critical period of the rat visual cortex (postnatal 3~5 weeks). However, in adult rats, the increase in 5-HT level in the brain by the administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine reinstates ocular dominance plasticity and LTP in the visual cortex. Here, we investigated the effect of 5-HT on the induction of LTP in the visual cortex obtained from 3- to 10-week-old rats. Field potentials in layer 2/3, evoked by the stimulation of underlying layer 4, was potentiated by theta-burst stimulation (TBS) in 3- and 5-weekold rats, then declined to the baseline level with aging to 10 weeks. Whereas 5-HT inhibited the induction of LTP in 5-week-old rats, it reinstated the induction of N-methyl-D-aspartate receptor (NMDA)-dependent LTP in 8- and 10-week-old rats. Moreover, the selective SSRI citalopram reinstated LTP. The potentiating effect of 5-HT at 8 weeks of age was mediated by the activation of 5-$HT_2$ receptors, but not by the activation of either 5-$HT_{1A}$ or 5-$HT_3$ receptors. These results suggested that the effect of 5-HT on the induction of LTP switches from inhibitory in young rats to facilitatory in adult rats.

• The Korean Journal of Physiology and Pharmacology
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• 제7권6호
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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.

• The Korean Journal of Physiology and Pharmacology
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• 제23권4호
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• pp.271-279
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• 2019

The lamina II, also called the substantia gelatinosa (SG), of the trigeminal subnucleus caudalis (Vc), is thought to play an essential role in the control of orofacial nociception. Glycine and serotonin (5-hydroxytryptamine, 5-HT) are the important neurotransmitters that have the individual parts on the modulation of nociceptive transmission. However, the electrophysiological effects of 5-HT on the glycine receptors on SG neurons of the Vc have not been well studied yet. For this reason, we applied the whole-cell patch clamp technique to explore the interaction of intracellular signal transduction between 5-HT and the glycine receptors on SG neurons of the Vc in mice. In nine of 13 neurons tested (69.2%), pretreatment with 5-HT potentiated glycine-induced current ($I_{Gly}$). Firstly, we examined with a $5-HT_1$ receptor agonist (8-OH-DPAT, $5-HT_{1/7}$ agonist, co-applied with SB-269970, $5-HT_7$ antagonist) and antagonist (WAY-100635), but $5-HT_1$ receptor agonist did not increase $I_{Gly}$ and in the presence of $5-HT_1$ antagonist, the potentiation of 5-HT on $I_{Gly}$ still happened. However, an agonist (${\alpha}$-methyl-5-HT) and antagonist (ketanserin) of the $5-HT_2$ receptor mimicked and inhibited the enhancing effect of 5-HT on $I_{Gly}$ in the SG neurons, respectively. We also verified the role of the $5-HT_7$ receptor by using a $5-HT_7$ antagonist (SB-269970) but it also did not block the enhancement of 5-HT on $I_{Gly}$. Our study demonstrated that 5-HT facilitated $I_{Gly}$ in the SG neurons of the Vc through the $5-HT_2$ receptor. The interaction between 5-HT and glycine appears to have a significant role in modulating the transmission of the nociceptive pathway.