• Biomolecules & Therapeutics
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• 제21권4호
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• pp.313-322
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• 2013

Previous studies have demonstrated that repeated administration of the exogenous stress hormone corticosterone (CORT) induces dysregulation in the hypothalamic-pituitary-adrenal (HPA) axis and results in depression and anxiety. The current study sought to verify the impact of catechin (CTN) administration on chronic CORT-induced behavioral alterations using the forced swimming test (FST) and the elevated plus maze (EPM) test. Additionally, the effects of CTN on central noradrenergic systems were examined by observing changes in neuronal tyrosine hydroxylase (TH) immunoreactivity in rat brains. Male rats received 10, 20, or 40 mg/kg CTN (i.p.) 1 h prior to a daily injection of CORT for 21 consecutive days. The activation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily CTN administration significantly decreased immobility in the FST, increased open-arm exploration in the EPM test, and significantly blocked increases of TH expression in the locus coeruleus (LC). It also significantly enhanced the total number of line crossing in the open-field test (OFT), while individual differences in locomotor activities between experimental groups were not observed in the OFT. Taken together, these findings indicate that the administration of CTN prior to high-dose exogenous CORT significantly improves helpless behaviors, possibly by modulating the central noradrenergic system in rats. Therefore, CTN may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression and anxiety disorders.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.639-645
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• 1997

The purpose of the present study is to determine the role of muscarinic cholinergic receptors of posterior hypothalamus in the central blood pressure regulation when respiration is controlled. In anesthetized and artificially ventilated rats, vasodepressor response was evoked by injection of L-glutamate(10 nmol) neuroexcitatory amino acid into the posterior hypothalamic area. The injection of $carbachol(0.5{\sim}8\;nmol)$ into the same area induced dose-dependent vasodepressor and bradycardic responses. Pretreatment with atropine(4 nmol) completely blocked the vasodepressor response to carbachol(2 nmol). In contrast, in spontaneously breathing rats, the injection of carbachol(8 nmol) into the posterior hypothalamic area induced the vasopressor and tachycardic responses. These results suggest that the muscarinic cholinergic receptors in the posterior hypothalamic area primarily play an inhibitory role in the central regulation of blood pressure and heart rate.

• 대한물리치료과학회지
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• 제9권4호
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• pp.53-61
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• 2002

This study was carried out to investigate the effects of electrical stimulation on the change oxytocin(OT) immunoreactive cells in the hypothalamus of the male SD rats. Fifteen healthy and normal male rats were divided into three groups, 5 SD rat in each group. The one group has been stimulated by electro-acupuncture(EA, 2Hz) for 30 min and the other group by EA for 1hr 30 min and control group has not been stimulated. The results were summarized as follows. OT immunoreactive cells were found in the Paraventricular nucleus (PVN), Supraoptic nucleus(SON) and Lateral Magnocellular Area(LMA). The number of OT immunoreactive cells of PVN were significantly increased after 30 min as compared with control group (p<0.05) and were also significantly increased after 1hr 30min than 30 min(p<0.05). The number of OT immunoreactive cells of SON were significantly increased after 30 min and 1hr 30 min(p<0.05) as compared with control group, but decreased after 1hr 30 min than 30 min. The number of immunoreactive hells of LMA significantly increased after 30 min(p<0.05) as compared with control group, but significantly decreased after 1hr 30 min than 30 min(p<0.05). These results show that OT is released into the hypothalamus in response to electrical stimulation.

• 대한약리학회지
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• 제30권1호
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• pp.39-48
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• 1994

포만중추 (satiety center)를 자극하여 음식섭취를 억제한다고 알려진 CCK-8을 흰쥐 복강에 투여하여, 흰쥐 뇌의 도파민 변화에 대한 CCK-8의 효과를 관찰하였다. 흰쥐 뇌의 부위별 도파민 함량은 HPLC-ECD방법으로 측정하였으며, 시상하부와 흑질에서의 TH-immunoreactive neuron은 면역조직화학법과 영상분석법을 시행하였다. 굶긴 쥐에서는 정상 쥐에 비하여, 도파민 함량이 전두 피질, 해마, 시상하부 및 편도체에서 각각 감소하였다. CCK-8을 투여한 쥐는 정상 쥐와 굶긴 쥐에 비하여, 도파민 함량이 시상하부에서 의미있게 감소하였다. 또한 굶긴 쥐는 정상 쥐와 비교하여, TH-positive neuron의 분포와 수가 뇌실옆핵, 깔때기핵, 정중융기 및 혹질에서 현저히 감소하였다. CCK-8투여시, 시상하부와 흑질에서의 TH-immunoreactive neuron의 수는 굶긴 쥐에 비하여 증가하였다. 이상의 실험 결과로 보아 음식물 섭취를 억제하는 작용이 있는 CCK-8은 시상하부의 도파민 신경계와 일부분 관련되어 있으며, 또한 시상하부와 흑질에 존재하는 TH-positive neuron은 음식물 섭취 행위에 중요한 역할이 있음을 시사하고 있다.

• 대한수의학회지
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• 제41권1호
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• pp.1-6
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• 2001

Pituitary adenylate cyclase activating polypeptide (PACAP)는 양의 뇌하수체에서 처음 분리 되었고, 뇌하수체 전엽세포의 cAMP의 생성을 자극하며, 흰쥐고환의 정자형성과 steroid 호르몬 형성에 관련한다고 알려져 있다. 이 연구는 성숙한 흰쥐의 고환에서 PACAP mRNA와 그 단백질의 분포를 조사하여 아래와 같은 결론을 얻었다. PACAP mRNA와 그 단백질은 흰쥐의 정세관에서 정자세포의 생성단계에 따라 특이적으로 발현되었다. 이들은 정세관의 발달단계 중 III~VII 기의 정자세포에서 발현되었고, 특히 V 기에서 초기 VII 기의 원형의 정자세포에서 가장 강하게 발현되었다. 이러한 결과는 흰쥐고환의 발달단계에 있는 정자세포에서 합성된 PACAP이 정자형성에 관련된다는 것을 나타내므로, PACAP이 고환의 기능에 중요한 역할을 하는 것을 암시한다.

• 동의생리병리학회지
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• 제17권6호
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• pp.1393-1403
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• 2003

The genetic effects of restraint stress challenge on HPA axis and the therapeutic effect of Boshimgeonbi-Tang on the stress were studied with cDNA microarray analyses on hypothalamus using an immobilization-stress mouse as stress model. Male CD-1 mice were restrained in a tightly fitted and ventilated vinyl holder for 2hours once a day, and this challenge was repeated for seven consecutive days. The body weights of the immobilization-stress mice were diminished about 25 percent degree as compared to normal ones. Seven days later, total RNA was extracted from the organs of the mouse, body-labeled with CyDye/sup TM/ fluorescence dyes (Amersham Bioscience Co., NJ), and then hybridized to cDNA microarray chip. Scanning and analyzing the array slides were carried out using GenePix 4000 series scanner and GenePix Pro/sup TM/ analyzing program, respectively. The expression profiles of 109 genes out of 6000 genes on the chip were significantly modulated in hypothalamus by the immobilization stress. Energy metabolism-, lipid metabolism-, apoptosis- and signal transduction-related genes were transcriptionally activated whereas DNA repair-, protein biosynthesis-, and structure integrity-related genes were down-regulated in hypothalamus. The 58 genes were up-regulated by the mRNA expression folds of 1.5 to 7.9. and the 51 genes were down-regulated by 1.5 - 3.5 fold. The 20 genes among them were selected to confirm the expression profiles by RT-PCR. The mRNA expression levels of Tnfrsf1a (apoptosis), Calm2 (cell cycle), Bag3 (apoptosis), Hspe1 (protein folding), Aatk (apoptosis), Dffa (apoptosis), Itgb1 (cell adhesion), Vcam1 (cell adhesion), Fkbp5 (protein folding), BDNF (neuron survival) were restored to the normal one by the treatment of Boshimgeonbi-Tang.

• The Korean Journal of Physiology and Pharmacology
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• 제26권4호
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• pp.255-262
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• 2022

Oxytocin is a neuropeptide produced primarily in the hypothalamus and plays an important role in the regulation of mammalian birth and lactation. It has been shown that oxytocin has important cardiovascular protective effects. Here we investigated the effects of oxytocin on vascular reactivity and underlying the mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and in rat aorta ex vivo. Oxytocin increased phospho-eNOS (Ser 1177) and phospho-Akt (Ser 473) expression in HUVECs in vitro and the aorta of rat ex vivo. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), inhibited oxytocin-induced Akt and eNOS phosphorylation. In the rat aortic rings, oxytocin induced a biphasic vascular reactivity: oxytocin at low dose (10^-9-10^-8 M) initiated a vasorelaxation followed by a vasoconstriction at high dose (10^-7 M). L-NAME (a nitric oxide synthase inhibitor), endothelium removal or wortmannin abolished oxytocin-induced vasorelaxation, and slightly enhanced oxytocin-induced vasoconstriction. Atosiban, an oxytocin/vasopressin 1a receptor inhibitor, totally blocked oxytocin-induced relaxation and vasoconstriction. PD98059 (ERK1/2 inhibitor) partially inhibited oxytocin-induced vasoconstriction. Oxytocin also increased aortic phospho-ERK1/2 expression, which was reduced by either atosiban or PD98059, suggesting that oxytocin-induced vasoconstriction was partially mediated by oxytocin/V1aR activation of ERK1/2. The present study demonstrates that oxytocin can activate different signaling pathways to cause vasorelaxation or vasoconstriction. Oxytocin stimulation of PI3K/eNOS-derived nitric oxide may participate in maintenance of cardiovascular homeostasis, and different vascular reactivities to low or high dose of oxytocin suggest that oxytocin may have different regulatory effects on vascular tone under physiological or pathophysiological conditions.

• 약학회지
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• 제34권5호
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• pp.311-322
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• 1990

This study primarily attempted to investigate the effects of methamphetamine on stereotyped behavior. Furthermore, an extensive experiment was conducted to examine the cortex methamphetamine concentration and levels of dopamine, serotonin, and their metabolites in striatum, septum and hypothalamus. Following treatment with 10 mg/kg methamphetamine, stereotyped behavior was observed in 10 minutes. Consequently female rats displayed more intense and longer lasting activity than the male. The concentration of cortex methamphetamine was even higher in female than male. The administration of methamphetamine increased the rate of dopamine turnover-i.e. lower dopamine, higher homovanillic acid in the striatum, septum. The highest rate was found in the striatum. Methamphetamine decreased the levels of serotonin, and its metabolite of 5-indoleacetic acid in the striatum, septum. An intensity in behavioral response was accompanied by an increase in dopamine turnover, a decrease in serotonergic transmission. The reduction of 3,4-dihydroxyphenylacetic acid-i.e. the metabolite of dopamine was due not to the inhibition of monoamine oxidase but to the induction of monoamine oxidase but to the induction of catechol-O-methyltransferase. The phenomenon of biogenic amines by methamphetamine concurred upon the concentration of methamphetamine in the brain. This process preceded stereotyped behavior. After single injection of 10 mg/kg methamphetamine, the levels of biogenic amines recovered within 6 hours.

• The Journal of Korean Physical Therapy
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• 제10권2호
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• pp.113-125
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• 1998

The neurotropic psudorabies virus(PRV) to replicate within neurons is very useful pathogen for neuronal tracing. I carried out this study to investigate the parametric analysis on the viral infection in the rat circadian control center with two genetically engineered strains out of PRV. The two strains are isogenic with the attenuated Bartha strain of PRV ; in one strain a lacZ reporter gene was inserted into the gC locus (PRV-BaBlu ; $4.75\times10^8pfu/ml$) and the other strain contained a PRV envelope glycoprotein gene(PRV-D ; $2.5\times10^8pfu/ml$) theat is absent in PRV-BaBlu. simultaneous or temporally separated sequential injection of$2{\mu}l$ of each strain into the vetreous body of eye produced a course of transsynaptic infection of retinohypothalamic circuitry. The results were as follows; 1. PRV-BaBlu and PRV-D infected the suprachiasmatic nucleus in hypothalamus and intergeniculate leaflet in lateral geniculate nucleus of thalamus. 2. The rate of PRV infection was dependent upon PRV strain. 3. Pre-infected neurons by PRV-D were interfered with the replication of PRV-BaBlu. 4. Dual injection of PRV-D and PRV-BaBlu showed more virulent than the parental strain.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.587-591
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• 2005

The effect of extremely low frequency (ELF,60Hz) magnetic fields (MFs) on convulsions was investigated in rats. We determined the onset arid duration of convulsions induced by bicuculline alone or by co-exposure to MFs and bicuculline. In addition, we measured the GABA concentrations in the rat brains using HPLC-ECD. MFs strengthened the convulsion induced by bicuculline (0.3, 1, and 3${\mu}g$, I.c.v.), with a shortening of the onset time, but lengthening of the duration time. Co-exposure to MFs and bicuculline decreased the GABA levels in the cortex, hippocampus and hypothalamus, whereas MFs alone reduced the level of GABA only in the hippocampus. These results suggest that the exposure to MFs may modulate bicuculline-induced convulsions due to GABA neurotransmissions in rat brains.