• 한국한의학연구원논문집
• /
• 제2권1호
• /
• pp.205-225
• /
• 1996

This study has been carried out to investigate the effects of Youngyanggaksan (YGS) extract on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. YGS extract prolonged significantly the beginning time to convulsion and time to death induced by strychnine. 2. YGS extract prolonged significantly the time to death induced by electrical shock of ECT unit (3sec, 200F, 25mA). 3. On the experiment of hypothermic effects of YGS extract on the rectal temperature of rats, YGS extract decreased significantly the rectal temperature of rats. 4. On the experiment of antipyretic effects of YGS extract on the febrile induced by the subcutaneous injection of $150{\mu}g/kg$ endotoxin in rats, YGS extract decreased significantly the rectal temperature of rats. 5. On the experiment of analgesic effects of YGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1ml/100g in rats, the writhing syndrome was reduced significantly by administration of YGS extract. 6. On the experiment of sedative effects of YGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of YGS extract. 7. On the experiment of effects of YGS extract on the activity of GABA-transaminase(GABA-T) in rat brains after 21 days of oral administration of YGS extract, the activity of GABA-T was reduced significantly by administration of YGS extract. 8. On the experiment of effects of YGS extract on the activity concentration of GABA in rat brains after 21 days of oral administration of YGS extract the activity concentration of GABA was reduced significantly by administration of YGS extract. 9. On the experiment of effects of YGS extract on the activity of GAD in rat brains after 21 days of oral adminstration of YGS extract, the activity of GAD was reduced significantly by administration of YGS extract. According to the those results, Youngyanggaksan extract reveals the effects on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system.

• The Korean Journal of Physiology and Pharmacology
• /
• 제8권2호
• /
• pp.111-115
• /
• 2004

Roundabout (Robo) is the transmembrane receptor for slit, the neuronal guidance molecule. In this study, the tyrosine phosphorylation of Robo was observed in Robo-transfected human embryonic kidney cells and developing rat brains, and found to be increased by the treatment with protein kinase A activator, forskolin. In contrast, protein kinase C activation by phorbol-12-myristate-13-acetate decreased the phosphorylation of Robo. Intracellular calcium was required for the tyrosine phosphorylation. Furthermore, the transfection of an Eph receptor tyrosine kinase dramatically enhanced the tyrosine phosphorylation. These findings indicate that the tyrosine phosphorylation of Robo is regulated by multiple mechanisms, and that Eph receptor kinases may play a role in the regulation of tyrosine phosphorylation of Robo in the rat brain.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권2호
• /
• pp.161-167
• /
• 1997

This study compares the subtypes of central beta adrenergic receptors (ARs) of brains of untreated rats with those of imipramine-treated rats. Beta adrenergic receptors were measured by quantitative autoradiography of the binding of $^3H$-dihydroalprenolol ($^3H$-DHA) in coronal sections of rat brain. Repeated treatment of rats with imipramine significantly reduced the binding of $^3H$-DHA to beta-1 AR in many brain areas, especially throughout the cerebral cortex, hippocampus, thalamus, and amygdala. Significant reductions of the binding of $^3H$-DHA to beta-2 AR were not found in any area of the brain. These data suggests that a selective down-regulation of beta-1 AR may be involved in the adaptive changes occurring after prolonged imipramine treatment.

• 약학회지
• /
• 제34권6호
• /
• pp.384-394
• /
• 1990

We studied the effect of carbon monoxide(CO)-induced bypoxia on monoamine neurotransmitter and their syntheitc enzyme in rat brain. When the rats were acute or chronic intoxicated at CO 5000 ppm for 30 minutes or 2000 ppm for 1 week each 3 hours, dopamine content increased significantly with decreasing of its turnover in striatum and norepinephrine content was diminished in hypothalamus. 5-hydroxytryptamine content was increased significantly and its turnover was decreased both in striatum and hypothalamus. Tyrosine hydroxylase activity was reduced in striatum. These results suggest that inhibition of TH activity in CO-induced hypoxia is owing to lack of oxygen supply threfore NE content is decreased. We suggest that increasing of dopamine and 5-hydroxytryptamine are due to reduction of its turnover.

• Clinical and Experimental Pediatrics
• /
• 제46권8호
• /
• pp.789-794
• /
• 2003

목 적: 신생 흰쥐의 뇌에 저산소-허혈을 유발하여 선조체 monoamine과 그 대사물들의 변화를 관찰하여, 저산소-허혈 손상 시 dopamine과 monoamine의 역할을 관찰하고자 하였다. 방 법 : 생후 5-6일 된 신생 흰쥐의 우측 총경동맥을 결찰 후 우측 선조체에 microdialysis probe를 삽입하였다. 2시간 동안의 안정기를 거친 후, probe를 통해 기저치를 수집하고, 바로 8% 산소에 2시간 동안 노출시키고, 2시간 동안 회복시키며 20분 간격으로 수집한 샘플을 HPLC를 통해 분석하였다. 결 과 : 1) Dopamine은 저산소-허혈기에 급격히 증가하는 경향을 보였으나 통계적 유의성은 없었다(P>0.05). 2) DOPAC은 저산소-허혈 동안 기저치의 $23.0{\pm}4.2%$까지 감소하였다가, 재산소화 동안에 기저치의 $120.8{\pm}54.9%$까지 증가하였다(P<0.05). 3) HVA는 DOPAC과 같은 변화를 보였으나 덜 현저하였고, 저산소-허혈 동안 기저치의 $35.3{\pm}7.6%$까지 감소하였다가 재산소화 동안에 $105.8{\pm}32.3%$까지 회복되었다(P<0.05). 4) NE은 저산소-허혈 노출과 재산소화 동안 유의한 변화를 보이지 않았다(P>0.05). 5) 5-HIAA는 저산소-허혈 동안 서서히 감소하였다가 재산소화 동안 증가하였고, 그 변화는 통계적으로 유의하였다(P<0.05). 6) 실험 중 serotonin은 검출되지 않았다. 결 론: 저산소-허혈은 미성숙 신생 횐쥐의 뇌 선조체의 monoamine 대사에 영향을 끼쳤으며, 이 결과는 monoamine, 특히 dopamine과 그 대사물들이 신생 흰쥐 뇌의 저산소-허혈손상의 기전에 중요한 역할을 할 수 있다는 가능성을 제시한다.

• 대한한의학회지
• /
• 제24권2호
• /
• pp.204-212
• /
• 2003

Current therapy for acute ischemic stroke is highly focused on neuroprotective agents, and many herbal medicines have been challenged for experimental models. The aim of this study is to investigate whether Angelicae gigantis Radix can protect nerve cells against ischemic neural damage of middle cerebral artery occlusion (MCAO) in rats' brains. Rats were treated with Angelicae gigantis Radix immediately after 2 hours of MCAO for 7 days. On the 7th day, the brains of the rats were sliced through the hippocampus and dyedby c-Fos immunohistochemistry stain and cresyl violet stain for microscopic examination. The number of viable neurons and c-Fos immunoreactive cells in CA1 regions was counted. MCAO caused significant decrease in density of neurons and c-Fos immunoreactive cells compared to those of sham-operated rats. Administration of Angelicae gigantis Radix significantly elevated MCAO-induced decrease in density of neurons and c-Fos immunoreactive cells. These results suggest that the neuroprotective effect of Angelicae gigantis Radix against focal cerebral ischemia is related to c-Fos gene expression. Thus, these findings indicate that Angelicae gigantis Radix can be used for treatment and prevention of cerebral ischemia.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권2호
• /
• pp.117-125
• /
• 1997

The N-methyl-D-aspartate (NMDA) receptor-mediated glutamatergic neurotransmission is involved in synaptic plasticity, developmental processes, learning and memory and many neuropathological disorders including age-related diseases. In the present study, regulation of the NMDA receptor properties by various ligands was investigated using $[^3H]MK-801$ binding studies in the synaptic membranes of young and aged rat forebrains. The binding in the presence of glutamate and glycine increased dramatically with growth between 1 and 6 weeks old, and thereafter declined gradually with aging. Glutamate, glycine or spermine respectively increased the binding with growth. Glutamate maintained the binding during aging, while glycine or spermine significantly decreased the binding in the aged brain. The maximum stimulation by glycine varied depending on the ages of brains. Greater sensitivity to glycine was observed at 1 week and 3 months and the sensitivity was significantly reduced in the aged brain. In contrast, spermine showed similar stimulation patterns in young and aged rats. These results indicated that the functional properties of the NMDA receptor-ion channel complex in young and aged rat forebrains are differentially regulated by agonists, and the reduction of the receptor function with normal aging may be, in some degree, due to the reduction of the receptor sensitivity to glycine.

• The Korean Journal of Physiology and Pharmacology
• /
• 제5권6호
• /
• pp.467-477
• /
• 2001

We examined astrocyte regional heterogeneity in their morphological changes in response to various stimuli. Astrocytes were cultured from six different neonatal rat brain regions including cerebral cortex, hippocampus, cerebellum, mid brain, brain stem and hypothalamus. Astrocyte stellation was induced by serum deprivation and the maximum stellation in different regional astrocytes was achieved after 2 h. After 24 h, in all astrocyte cultures, the level of stellation returned to their original level. Cerebellar or hypothalamic astrocytes were the most or the least sensitive, respectively, to serum deprivation. The order of maximum sensitivity to serum deprivation among different regional astrocytes was: cerebellum＞mid $brain{\ge}hippocampus,\;brain\;stem{\ge}cerebral$ cortex＞hypothalamus. Isoproterenol-induced astrocyte stellation was also examined in different regional astrocytes, and similar order of maximum sensitivity as in serum deprivation was observed. Next a possible developmental effect on astrocyte morphological changes was examined in cerebral cortex and cerebellum astrocytes cultured from postnatal day 1 (P1), P4 and P7 rat brains. A much higher sensitivity of cerebellum astrocytes to serum deprivation as well as isoproterenol treatment was consistently observed in P1, P4 and P7-derived astrocytes compared to cerebral cortex astrocytes. The present study demonstrates different regional astrocytes maintain different levels of morphological plasticity in vitro.

• Journal of the Optical Society of Korea
• /
• 제13권1호
• /
• pp.166-170
• /
• 2009

NIRS (Near-infrared spectroscopy) is a relatively, new, non-invasive, and non-ionizing method of measuring hemodynamic responses in thick biological tissues such as the cerebral cortex. In this study, we measured the hemodynamic responses of the rat barrel cortex to whisker stimulation by using a frequency-domain NIRS system. We designed multiple optical probes comprising multi-mode optical fibers and manipulating arms, both of which can be easily applied to small animals. Various electrical stimulations were applied to rat whiskers at different voltage levels and stimulation frequencies. Our results show that the hemodynamic responses are highly dependent on the stimulation voltage level, and not so much on stimulation frequency. This paper suggests that NIRS technology is highly suitable for the study of small animal brains.

• Clinical and Experimental Pediatrics
• /
• 제49권2호
• /
• pp.198-202
• /
• 2006

목 적 : Fas는 세포표면 수용체로 세포사멸 신호를 전도한다. 많은 질환에서 세포표면의 Fas가 Fas ligand(FasL)와 결합하여 세포사멸 과정을 유발하게 된다. 연구자들은 7일된 신생 흰쥐에 저산소성 허혈성 손상을 유발한 후 뇌 해마에서 Fas와 FasL의 발현을 관찰하고자 하였다. 방 법 : 7일된 신생 흰쥐를 오른쪽 총 경동맥 영구 결찰 후 8% 산소에 2시간 노출시켰다. 저산소성 허혈성 손상 후 12, 24, 48시간에 뇌를 적출 냉동 보관하였다. Western blotting 방법과 면역형광염색 방법으로 냉동 보관된 뇌의 경동맥을 결찰한 오른 쪽 해마에서 Fas와 FasL의 발현을 관찰하였다. 결 과 : Fas와 FasL의 발현은 저산소성 허혈성 손상 후 12시간에 경동맥이 결찰된 오른쪽 해마에서 크게 증가하고 이후 감소하는 것을 western blotting 방법에 의해 관찰하였다. Fas와 FasL의 면역형광발현은 오른쪽 해마의 CA1 영역에서 손상 후 12시간과 24시간에 대조군에 비해 증가하였다. Fas의 면역형광 발현은 손상 후 48시간에 감소하였으나 FasL의 면역형광발현은 손상 후 48시간에도 지속되었다. 결 론 : 세포표면에서 Fas와 FasL의 발현과 그들의 결합은 저산소성 허혈성 손상을 받은 미성숙 뇌의 신경세포 손상에 기여할 것으로 추측되었다.