• 대한약리학회지
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• 제20권2호
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• pp.59-71
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• 1984

신장기능에 대한 중추신경계의 역할을 구명코자. presynaptic ${\alpha}-adrenoceptor$의 선택적 작동약인 clonidine을 urethane마취 가토의 측뇌실내로 (icv)투여하여 신장기능의 변동을 관찰하였다. $5{\mu}g/kg$ icv이하의 양으로는 신장기능의 유의한 변동을 볼 수 없었으나, $15{\mu}g/kg$ icv 으로는 20분간에 걸쳐 현저한 Na 및 K배설 증가를 볼 수 있었다 이 때 신혈류 및 사구체 여과율은 유의한 변동을 나타내지 아니하였다. 또 이때 Na 재흡수율은 유의하게 감소하였으며, Na배설증가 작용이 세뇨관에서의 Na재흡수 억제에 기인함을 알 수 있었다. 전신혈압 변동은 이 작용에 기여하지 아니하였다. Presynaptic ${\alpha}-adrenoceptor$에 대한 선택적 길항약인 yohimbine $100\;{\mu}g/kg$을 clonidine투여 20분전에 측뇌실내로 투여하면 clonidine의 신장작용이 완전히 차단되었다. 이 량의 yohimbine은 측뇌실내 투여시 신장기능에 아무런 변동도 초래하지 아니하였다. $15\;{\mu}g/kg$ clonidine을 정맥내로 투여하면 투여 직후에 뇨량 감소와 신장기능 감퇴를 초래한 뒤 후기에 약간의 Na배설증가의 경향을 보였으나, clonidine을 icv로 투여하였을 때 볼 수 있던 만큼의 Na배설증가는 볼 수 없었다. 따라서 icv clonicine의 신장작용에는 신장에 대한 clonidine의 직접작용이 관여하지 않음을 알 수 있었다. 이 연구결과는 가토의 신장기능 조절에 있어서 중추의 교감신경 긴장도가 중요한 역할을 하고 있음을 시사하였다.

• 대한수의학회지
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• 제33권1호
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• pp.71-80
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• 1993

The central nervous system depressant effect of xylazine and xylazine-ketamine was studied in chicken and mice. Intraperitoneal injection of xylazine(1~30 mg/kg) and xylazine(1~30 mg/kg)-ketamine(100 mg/kg) induced a loss of the righting reflex in chicken and mice, respectively. These effects of xylazine were dose-dependent. The results obtained were as follows; 1. The effect of xylazine-induced depression was antagonized by adrenergic antagonists having ${\alpha}_2$-blocking activity(yohimbine, tolazoline, piperoxan and phentolamine). 2. Yohimbine was most effective in the reduction of the CNS depression by xylazine. 3. Phenoxybenzamine and prazosin did not reduced CNS depression by xylazine in both species. 4. Labetalol (${\alpha}_1$, ${\beta}_1$-adrenergic antagonist) and propranolol(${\beta}$-adrenergic blocking agent) were not effective in reducing xylazine induced depression. 5. Cholinergic blocking agents (atropine and mecamylamine), a dopaminergic antagonist (Haloperidol), a histamine $H_1$-antagonist(chlorpheniramine), a histamine $H_2$-antagonist(cimetidine), a serotonergic-histamine $H_1$ antagonist(cyproheptadine) were not effective in reducing xylazine-induced depression. 6. Xylazine-induced depression is mediated by ${\alpha}_2$-adrenergic receptors and appears not to be involved in cholinergic, dopaminergic, serotonergic or histaminergic pathways.

• The Korean Journal of Physiology
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• 제21권1호
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• pp.67-77
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• 1987

Effect of intravenously injected clonidine on the flexion reflex was studied in 15 decerebrated and spinalized cats. The flexion reflex was elicited by electrical stimulation of the tibial nerve or the common peroneal nerve and it was recorded as single unit activity from filaments of the L6 or L7 ventral roots. In order to obtain the late flexion reflex discharges, $A{\delta}$ and C afferent fibers were stimulated with single or train electrical pulses respectively. The flexion reflex, especially the late component, was markedly inhibited after intravenous administration of clonidine. The clonidine-induced inhibition of the flexion reflex was compared before and after treatment of the animals respectively with yohimbine and naloxone. The inhibitory effect on the flexion reflex of clonidine was not altered by naloxone, a ${\mu}-opioid$ receptor blocker, whereas it was completely blocked by yohimbine, an ${\alpha}_2-adrenergic$ antagonist. These results indicate that clonidine inhibits the flexion reflex through excitation of ${\alpha}_2-adrenoceptors$ even at the spinal cord level.

• Natural Product Sciences
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• 제4권2호
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• pp.58-61
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• 1998

Eurycoma longifolia Jack was evaluated for aphrodisiac property on sexually naive male mice using the electrical copulation cage. Optimum condition was provided for this study and the male mice were treated with 500 mg/kg of either chloroform, methanol, water or n-butanol fractions from E. longifolia Jack. However, the mice in the yohimbine and control groups received 30 mg/kg and 3 ml/kg of yohimbine and normal saline respectively. The male mice were then conditioned to seek either an estrous female, sexually vigorous male or no mouse, a measurement of right, wrong or no choice respectively. Besides this, hesitation time which was the time spent before the sexually naive male mice crossed the electrical grid (maintained at 0.12 mA) was also determined. Results showed that E. longifolia Jack possesses aphrodisiac property on the sexually naive male mice as shown by the slow and transient reduction in hesitation time and also a similar manner in the increase in the % of sexually naive male mice scoring right choice throughout the investigation period. Hence, this further supports the folkuse of this plant as aphrodisiac.

• 한국동물위생학회지
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• 제17권3호
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• pp.255-263
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• 1994

To elucidate the action of the adrenergic nerve on the isolated uterine smooth muscle of the pig, effects of electrical transmural nerve stimulation and norepinephrine were investigated on the pretreatment of phentolamine ； non-selective ${\alpha}$-adrenoceptor blocker, propranolol ; ${\beta}$-adrenoceptor blocker and the yohimbine；${\alpha}_2$-selective adrenoceptor blocker from physiograph. 1. The relaxation response induced by norepinephrine was the concentration of $10^{-6}$ M at first and maximum response was concentration of $10^{-4}$M. 2. The relaxation response induced by norepinephrine was not effected by the pretreatment with non-selective $\alpha$-adrenoceptor blocker, phentolanune ($10^{-6}$ M) but was completely blocked by the pretreatment with ${\beta}$-adrenoceptor blocker, propranolol($10^{-6}$ M). 3. The contractile response induced by electrical transmural nerve stimulation(20V, 10Hz, 0.5msec, 20sec ) was inhibited by the pretreatment with non-selective ${\alpha}$-adrenoceptor blocker, phentolamine($10^{-6}$ M) but was not inhibited and rather increased by the pretreatment ${\beta}$-adrenoceptor blocker, propranolol($10^{-6}$ M), and was not approximately effected by the pretreatment with ${\alpha}_2$-adrenoceptor blocker, yohimbine($10^{-6}$ M). These finding suggest that it was excitatory action by ${\alpha}_1$-adrenergic nerve and inhibitory action by ${\alpha}_2$-adrenergic, ${\beta}$-adrenergic nerve on uterine smooth muscle of the pig.

• Journal of Korean Neurosurgical Society
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• 제47권6호
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• pp.420-423
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• 2010

Objective : Peripheral nerve injury often leads to neuropathic pain, which is characterized by burning pain, allodynia, and hyperalgesia. The role of the sympathetic nervous system in neuropathic pain is a complex and controversial issue. It is generally accepted that the alpha adrenoreceptor (AR) in sympathetic nerve system plays a significant role in the maintenance of pain. Among alpha adrenoreceptor, alpha-1 receptors play a major role in the sympathetic mediated pain. The primary goal of this study is to test the hypothesis that sympathetically maintained pain involves peripheral alpha-2 receptors in human. Methods : The study was a randomized, prospective, double-blinded, crossover study involving twenty patients. The treatments were : Yohimbine (30 mg mixed in 500 mL normal saline), and Phentolamine (1 mg/kg in 500 mL normal saline) in 500 mL normal saline at 70 mL/hr initially then titrated. The patients underwent infusions on three different appointments, at least one month apart. Thus, all patients received all 2 treatments. Pain measurement was by visual analogue scale, neuropathic pain questionnaire, and McGill pain questionnaire. Results : There were significant decreases in the visual analogue scale, neuropathic score, McGill pain score of yohimnine, and phentolamine. Conclusion : We conclude that alpha-2 adrenoreceptor, along with alpha-2 adrenoreceptor, may be play role in sympathetically maintained pain in human.

• 대한수의학회지
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• 제33권2호
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• pp.211-216
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• 1993

To elucidate the action of the cholinergic and ${\alpha}_2$-adrenergic nerve on the isolated ileal smooth muscle of the dog, effect a of electrical field stimulation were investigated on the pretreatment of the physostigmine; cholinestrase inhibitor, yohimbine; ${\alpha}_2$-adrenoceptor blocker, atropine ; cholinergic receptor blocker and phentolamine; non-selective $\alpha$-adrenoceptor blocker from physiograph. 1. The contractile response induced by electrical field stimulation was the frequency (2-40 Hz)-dependent manner. 2. The contractile response induced by electrical field stimulation was markedly increased by the pretreatment of physostigmine$(1{\mu}M)$; cholinestrase inhibitor. 3. The contractile response induced by electrical field stimulation was increased by the pretreatment of yohimbine$(1{\mu}M)$; ${\alpha}_2$-adrenoceptor blocker. These finding suggest that it was powerful excitatory action by cholinergic nerve and inhibitory action by ${\alpha}_2$-adrenergic nerve on ileal smooth muscle of the dog.

• 약학회지
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• 제48권5호
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• pp.285-290
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• 2004

The purpose of this study is to prove how magnetic field (MF) acts on sympathetic neuro-transmissions using thermal response. Mice were divided into two groups and each one was exposed to MF (20 G, 24 hrs) or sham. Every vehicle or drugs were treated a half hour before the thermal response test. The pain threshold was lowered by MF (20 G, 24 hrs) alone. This reduction of pain threshold by MF was not blocked by a single treatment of $\alpha$-receptor antagonist (prazosin), $\alpha$$_2$-receptor agonist (clonidine, guanabenz), $\beta$$_1$-receptor antagonist (atenolol) or $\beta$$_1$,$\beta$$_2$-receptor antagonist (propranolol). But administration of $\alpha$$_2$-receptor antagonist (yohimbine) completely inhibited the decrease in pain threshold by MF. Moreover, it increased by high dose of yohimbine over normal condition. These results suggest that MF acts on sympathetic nerve terminal to induce hyperalgesia, in which pre-synaptic az receptor might be involved.

• 대한약리학회지
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• 제30권1호
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• pp.29-37
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• 1994

배외측 뇌교의 전기자극은 척수 수준에서 동통의 역치를 증가시키고, 또한 말초로 부터 오는 유해성 자극에 의해 야기되는 척수후각세포의 흥분성을 억제하여 진통효과를 나타낸다. 이러한 진통효과는 noradrdnergic 원심신경을 매개로 한다고 하였지만, 이직까지 이를 직접적으로 뒷받침하는 신경화학적인 증거는 보고되지 않았다. 따라서 본 실험은 뇌교에 위치한 청반핵(Locus coeruleus)의 전기자극시, 척수 수준에서 일어나는 동통조절효과를 쥐꼬리 회피 반사(Tail Flick Reflex)를 이용해 관찰하고, 이러한 동통조절효과는 어떤 신경전달물질을 매개로해서 일어나며, 또한 생체내에서 직접 유리 되는지 살펴보기 위해 Push Pull technique을 이용해 척수액내 noradrenaline의 농도 변화를 HPLC로 측정하였다. 청반핵자극시의 동통조절기전을 알아보기위해 yohimbine, naloxone 그리고 vehicle의 3group 으로 나누어 각 길항제의 효과를 실험하였다. 청반핵 자극시 TF latency의 증가(>6.Ssec)를 보이는 역치 자극강도가 yohimbine $30{\mu}g$을 척수내로 투여한 후에는 $135\;{\mu}A$로서 안정시의 $55\;{\mu}A$에 비해 147% 증가되어 유의한 변화를 보여주었다(P<0.01, n=5). $Naloxone\;20{/mu}g$을 투여한 실험군 에서도 초기 역치자극강도 $54\;{\mu}A$에서 $120\;{\mu}A$로서 123% 증가되어 역시 유의한 변화를 보여주었다(P<0.01, n=5). 그러나 vehicle group에서는 투여 전, 후 역치자극강도의 변화가 없었다. 청반핵 자극이 없는 안정상태에서의 TF latency 값은 모두 3.1 sec였고 yohimbine과 naloxone투여후에는 각각 2.5 sec,2.6sec로 감소되어, 긴장성 억제가 차단되는 것으로 나타났다(각각 P<0.05,P<0.1,n=5).청반핵의 전기자극$(100\;{\mu}A)$은 척수액내 noradrenaline의 농도를 증가시켰으나(평균 4.18mg/ml에서 7.74 ng/ml로, p<0.05, n=10),dopamine의 농도는 증가되지 않았다. 이상의 결과는 청반핵 자극에 의한 척수내 동통조절효과는 opioid 계외에 부분적으로 noradrdnaline을 매개로 해서 이루어지며, 이에 관여하는 수용체는 ${\alpha}_2$ 임을 보여주었다.

• 대한약리학회지
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• 제17권2호
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• pp.23-30
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• 1981

1) 흰쥐 및 가토정관표본(家兎精管標本)에서 전기자극(電氣刺戟)(Field Stimulation)에 의한 수축반응(收縮反應)에 미치는 McN-A-343. cocain 및 clonidine등 그 작용(作用)에 NE와의 유관성(有關性)이 시사(示唆)되어 있는 약물(藥物)의 영향(影響)을 조사(調査)하였다. 2) 소양(小量)의 McN-A-343$(0.003,\;0.03,\;0.3{\mu}\;g/ml)$, clonidine$(0.003,\;0.03\;{\mu}g/ml)$, cocaine$(0.03\;{\mu}g/ml)$존재하(存在下)에서 $5{\sim}10Hz$에 의한 자극효과(刺戟效果)는 억제(抑制)되었고 이 억제(抑制)는 yohimbine, piperoxan 투여(投與)에 의하여 원수축반응(原收縮反應)으로 회복(回復)되었다. 3) 전술(前述)한 McN-A-343$(0.03\;{\mu}g/ml)$ 또는 cocaine $(0.03\;{\mu}g/ml)$에 의한 억제(抑制)는 각각 동량(同量)의 cocaine 또는 McN-A-343으로 더욱 강화(張化)되었다. 이 강화(强化)된 억제효과(抑制效果)는 yohimbine으로 회복(回復)되었다. 4) 비교적(比較的) 대량(大量)의 McN-A-343$(30\;{\mu}g/ml)$ 및 cocaine$(3\;{\mu}g/ml)$존재하(存在下)에서 $5{\sim}10Hz$ 및 0.01 Hz의 자극효과(刺戟效果)는 강화(强化)되었다. 이 강화(强化)는 thymoxamine 존재하(存在下)에서 소실(消失)되었고, atropine 존재하(存在下)에서는 McN-A-343의 강화(强化)만이 소실(消失)되었다. 5) Muscarine에 의하여 자극효과(刺戟效果)는 강화(强化)되었고 이 강화(强化)는 thymoxamine 및 atropine 존재하(存在下)에서 억제(抑制)되었다. 6) 흰쥐 정관표본(精管標本)의 0.01 Hz의 자극효과(刺戟效果)는 McN-A-343 또는 clonidine에 의하여 억제(抑制)되었고, yohimbine 존재하(存在下)에서 후자(後者)에 의한 억제(抑制)는 부분회복(部分回復)되었으나 전자(前者)에 의한 억제(抑制)는 영향(影響)받지 않았다. 7) 이상(以上)의 성적(成績)으로 McN-A-434은 교감신경말단(交感神經末端)으로부터의 NE유리(遊離)에 대하여 상반(相反)된 두가지 작용(作用) 즉(卽) $pre-{\alpha}$를 통(通)한 NE유리(遊離)의 억제(抑制) 및 muscarinic recepor를 통(通)한 NE유리(遊離)의 증가(增加)를 일으키는 성질(性質)을 갖고, cocain(소량(少量))은 NE-uptake 억제(抑制)에 의하여 NE를 통(通)해 $pre-{\alpha}$에 작용(作用)하여 NE유리(遊離)를 억제(抑制)시키는 성질(性質)을 갖고 있음을 알 수 있다.