• 약학회지
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• 제35권4호
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• pp.295-300
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• 1991

Ralationship between noradrenergic nervous system activity and luteinizing hormone releasing hormone(LHRH) content mediated by testosterone in hypothalamus was tested. Three groups of adult male animals were prepared; (1) Intact; (2) Castration+Vehicle (Cast+V); (3) Castration+Testosterone (Cast+T). Silastic capsule containing vehicle or testosterone was implanted into neck region of animals two weeks following castration. Norepinephrine content, alpha-adrenergic receptor binding characteristics using H$^{3}$-WB4101, and content of LHRH by LHRH RIA procedure were determined. Testosterone replacement to castrated male rats augmented the content of norepinephrine and LHRH. Testosterone replacement increased the alpha-adrenergic receptor density but did not change alpha-receptor affinity. The data from the present study suggest that increase in LHRH content by testosterone may be positively coupled to the activity of central noradrenergic nervous system.

• 대한약리학회지
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• 제23권2호
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• pp.87-94
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• 1987

스트레스로 인한 위궤양형성에 중추성 교감신경의 영향여부를 추구하기 위하여 norepinephrine, epinephrine, dopamine, isoproterenol 및 clonidine을 흰쥐의 뇌실내로 투여 하고 한냉 환경 $(4^{\circ}C)$에서 4시간 구속방치하여 위 분비기능의 변동과 궤양 발생 정도를 검색하여 다음과 같은 결과를 얻었다. 1. Norepinephrine, epinephrine, dopamine및 소량의 clonidine 처치로 궤양 발생이 현저하게 감소하였다. 2. Norepinephrine또는 epinephrine 처치군에서는 위액분비, 산분비 및 펩신 분비의 감소와 궤양 발생 감소가 초래되었다. 3. Dopamine혹은 소량의 clonidine 처치군에서는 궤양 발생의 감소와 위액분비 및 산분비 감소가 초래되었으나 펩신 분비는 변동 없었다. 4. Isoproterenol처치군에서는 궤양 발생과 펩신 분비는 대조군과 차이 없고, 위액분비 및 산분비의 감소만 나타났다. 5. 대량의 clonidine 투여군에서는 궤양발생, 산분비 및 펩신분비 모두 변동없이 약간의 위액분비 감소가 나타났다 이상의 결과로 보아 중추성 교감신경자극은 궤양 형성을 억압하는 작용이 있고, 이에는 교감신경성 ${\alpha}$-수용체 및 도파민성 수용체가 관여된다고 믿어지며, 이 효과는 위액분비 감소 및 산 분비 감소작용과 아울러 또 다른 요인이 관여한다고 추측된다.

• 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.

• 대한약리학회지
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• 제11권2호
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• pp.19-27
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• 1975

Haloperidol, a butyrophenone, was synthetized by Janssen and introduced for the treatment of psychosis. Although structurally different from the phenothiazines, the butyrophenones share many of their pharmacological properties, such as inhibition of conditioned avoidance response, blocking effect of amphetamine reaction, producing catalepsy, antishock effect and protection against the lethal effects of catecholalmines. Chlorpromazine can lower the arterial blood pressure through its adrenergic blocking activity, its direct effect in relaxing vascular smooth muscle, its direct effect in depressing the myocardium and its action in a complex manner on the central nervous system. In the case of haloperidol, however, was not clarified the mechanism of lowering the blood pressure. The present paper describes the effects of haloperidol on cardiovascular system to investigate the mechanisms of its actions on the arterial blood pressure. The results are followings; 1. In anesthetized cats, intravenous administration of haloperidol and chlorpromazine in the dose of 0.1mg/kg produced a slight decrease in the blood pressure, which followed by complete recovery within $30{\sim}60$ minutes. In the dose of 3mg/kg, however, both produced an abrupt and marked decrease of the blood pressure, which followed by delayed recovery. 2. Haloperidol in the dose ranges of 0.1mg to 3.0mg/kg tended to produce the heart rate slowing in the cats, while chlorpromazine has no effect on the rate. 3. Following administration of haloperidol or chlorpromazine, epinephrine reversal in the arterial blood pressure was observed in the cat, however the responses of norepinephrine and acetylcholine were little affected. 4. In the isolated rabbit atrium the contractility was depressed by haloperidol in the doses over 0.5mg per 100ml, but the rate was not affected. In contrast, the epinephrine-induced contractility was not depressed after haloperidol treatment. However, the increased rate of atrium by epinephrine was partially blocked after haloperidol. 5. In the isolated rabbit aortic strip, epinephrine-induced contraction was blocked by haloperidol. With the above results, it may be concluded that the hypotensive effect of haloperidol was largely due to ${\alpha}$-adrenergic blocking properties and the direct effect in depressing the myocardium as well as its action on central nervous system.

• 대한약리학회지
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• 제16권2호
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• pp.31-38
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• 1980

Calvert et al. formulated the hypothesis that carbon tetrachloride ($CCl_4$) acted on the central nervous system to produce and intensify sympathetic discharge which resulted in anoxic necrosis of the liver. Recknagel suggested that the essential feature of $CCl_4$ hepatotoxicity depended on the cleavage of it to $CCl_3$(free radical) and the peroxidative decomposition of cytoplasmic membrane structural lipids. And there are many reports which show the increase of adrenergic activity in hyperthyroidism. In this paper, the influence of thyroxine on the hepatotexicity of carbon tetrachloride was investigated in mice. The results obtained were summarized as follows; 1) Hepatic total lipid and lipid peroxide contents were slightly decreased by L-sodium thyroxine injection(4mg/kg/day for 4days or 6days), but hepatic glycogen content was significantly decreased. 2) Hepatic total lipid and lipid peroxide contents and serum lactic dehydrogenase activity were significantly increased by $CCl_4$ (4 ml/kg single dose or triple dose: 4ml/kg/day for 3days), but hepatic glycogen content was significantly decreased. 3) The increase of hepatic total lipid and lipid peroxide contents and serum lactic dehydrogenase activity induced by $CCl_4$ were significantly inhitited by the pretreatment of thyroxine. 4) The decrease of hepatic glycogen induced by $CCl_4$ was not affected by the pretreatment of thyroxine.

• 대한약리학회지
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• 제24권2호
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• pp.153-164
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• 1988

The potential role of endogenous opioid peptides (EOPS) in cardiovascular regulation has only recently been entertained. EOPS have been localized in brain, spinal cord, autonomic ganglia, particularly the adrenal gland, and many other peripheral tissues. There are at least five major types of opioid receptors; namely ${\mu},\;{\delta},\;k,\;{\sigma},\;and\;{\varepsilon}$ and Experimental evidence indicates that cardiovascular actions of the peptide are mediated primarily by ${\mu},\;{\delta}$ and k receptors, and that these receptor types may be allosterically coupled. In anesthetized rabbits met-enkephalin decreased blood pressure and heart rate, which closely paralleled a reduction in sympathetic discharge. Naloxone, but not naloxone methobromide, antagonized these effects, which suggests a central site of action of met-enkephalin. A number of autonomic agents, particularly adrenergic ${\alpha}$-and, ${\beta}-agonists$ and antagonists modify the cardiovascular actions of met-enkephalin. Experiments in reserpine-treated and adrenalectomized rats provide no evidence of sympathetic nervous system involvement in the pressor responses to intravenous injection of opioid peptides, but rather suggest a direct peripheral action. Finally, activation of a beta-endorphinergic pathway projecting from the arcuate nucleus to the nucleus tractos solitarii in rats can cause naloxone reversible hypotension and bradycardia. There is evidence to implicate this pathway in antihypertensive drug action and in the modulation of baroreflex activity.