• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.753-761
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• 1998

Preconditioning of a heart with small doses of catecholamines induces a tolerance against the subsequent lethal ischemia. The present study was performed to find a specific receptor pathway involved with the catecholamine preconditioning and to test if adenosine plays a role in this cardioprotective effect. Isolated rat hearts, pretreated with small doses of ${\alpha}-\;or\;{\beta}-adrenergic$ agonists/antagonists, were subjected to 20 minutes ischemia and 20 minutes reperfusion by Langendorff perfusion method. Cardiac mechanical functions, lactate dehydrogenase and adenosine release from the hearts were measured before and after the drug treatments and ischemia. In another series of experiments, adenosine $A_1\;or\;A_2$ receptor blockers were treated prior to administration of adrenergic agonists. Pretreatments of a ${\beta}-agonist,\;isoproterenol(10^{-9}{\sim}10^{-7}\;M)$ markedly improved the post-ischemic mechanical function and reduced the lactate dehydrogenase release. Similar cardioprotective effect was observed with an ?-agonist, phenylephrine pretreatment, but much higher $concentration(10^{-4}\;M)$ was needed to achieve the same degree of cardioprotection. The cardioprotective effects of isoproterenol and phenylephrine pretreatments were blocked by a ${\beta}_1-adrenergic$ receptor antagonist, atenolol, but not by an ${\alpha}_1-antagonist,$ prazosin. Adenosine release from the heart was increased by isoproterenol, and the increase was also blocked by atenolol, but not by prazosin. A selective $A_1-adenosine$ receptor antagonist, 1,3-dipropyl-8-cyclopentyl xanthine (DPCPX) blocked the cardioprotection by isoproterenol pretreatment. These results suggest that catecholamine pretreatment protects rat myocardium against ischemia and reperfusion injury by mediation of ${\beta}_1-adrenergic$ receptor pathway, and that adenosine is involved in this cardioprotective effect.

• 한국임상약학회지
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• 제10권3호
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• pp.107-110
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• 2000

Theophylline and $\beta$-adrenergic agonists are frequently used together in patients with respiratory diseases. However the clinical impact of $\beta_2$-adrenergic agonists on the blood concentration of theophylline is not fully evaluated. Formoterol, a newly available oral ${\beta}_2$-adrenergic agonist is frequently used in pediatric respiratory patients. The objective of this study was to investigate the effect of oral formoterol on theophylline's blood concentration. Randomized prospective study was conducted. Twenty-four children were enrolled on the study. Their age ranged 2 to 73 months (mean 35.8 months). Theophylline group (12 patients) received 10 mg/kg/day of for theophylline orally. Theophylline/formoterol group (12 patients) received 10 mg/kg/day of theophylline and $4\;{\mu}g/kg/day$ of formoterol orally. All medications were administered at least for 5 days starting on admission day. Theophylline's trough concentrations were obtained on days 3 and day 5. Pulse rates were recorded before the study medications were given on admission, and days 3 and day 5. Statistical significance was calculated by two-tailed Student's t-test. Theophylline's levels in children given theophylline and formoterol together were lower an those given theophylline alone ($6.38\pm0.90\;{\mu}g/ml\;vs\;7.43\pm0.77\;{\mu}g/ml$ on day 3(p<0.05), $5.62\pm0.56\;{\mu}g/ml\;vs.\;6.78\pm0.61\;{\mu}g/ml$ on day 5 (p<0.05)). In both groups, theophylline's trough concentration on day 5 were lower than day 3. There was no significant side effects in both groups. In conclusion, the new ${\beta}_2$ selective adrenergic agonist formoterol reduced serum theophylline levels in children with respiratory diseases. Further investigation is needed to clarify the long term effect of this drug interaction.

• 한국환경성돌연변이발암원학회지
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• 제21권2호
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• pp.95-98
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• 2001

$\beta$$_2$-Adrenergic receptors($\beta$$_2$-AR) contribute to cardiovascular regulation by influencing several functions and a several studies suggest that a decreased function of the $\beta$$_2$-AR may be involved in essential hypertension. We investigated the Arg16Gly mutation of $\beta$$_2$-AR gene, which show enhanced agonist-promoted downregulation of the receptor and yielded different results in terms of association with essential hypertension. We studied the relationship between genetic variation in the $\beta$$_2$-adrenergic receptor gene and hypertension in a Korean population using Nde I restriction fragment length polymorphism (RFLP) analysis. There were significant differences in allele and genotype frequencies between essential hypertensive and normotensive group (Odds ratio(CI) = 1.71 (1.09-2.70)). Therefore, our result suggests that the Nde I RELP of the $\beta$$_2$-adrenergic receptor gene may be useful as a genetic marker in hypertension diagnostics in Korean population.

• 대한약리학회지
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• 제22권1호
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• pp.24-33
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• 1986

본 연구에서는 개구리(Rana nigromaculata)의 피부에 있어서 전위차(PD), 단락전류(SCC) 및 total skin conductance(TSC)에 미치는 제종 adrenergic agonist 및 그 차단제의 영향을 관찰하여 개구리 피부에 adrenoceptors의 존재를 확인하고 Na 수송에 있어 그들의 역할을 구명코자 하였다. 1.Norepinephrine(NE, $6{\times}10^{-8}-6{\times}10^{-5}M$), phenylephrine($PE,5{\times}10^{-6}-5{\times}10^{-4}M$)의 PD 및 epinephrine(Epi, $5.5{\times}10^{-7}-5.5{\times}10^{-5}M$)의 PD 및 SCC 증가효과는 약물의 투여농도에 비례하였으며, Epi의 최대효과는 NE나 PE의 것보다 약하였다. 2. 이러한 PD 및 SCC의 증가효과는 alpha 1 adrenoceptor 차단체인 prazosin $2{\times}10^{-6}M$에 의해서 억제되었으며, 특히 Epi의 증가효과는 불가역성 alpha receptor 차단제인 phenoxybenzamine $3.3{\times}10^{-5}M$에 의하여 완전히 차단되며 대량의 Epi에 의해서는 PD 및 SCC의 감소를 초래하였다. 3. Beta adrenoceptor agonist인 isoproterenol$(5{\times}10^{-7}-5{\times}10^{-6}M)$에 의해 농도증가에 비례한 PD 및 SCC의 감소가 일어났으며, 이는 선택적 bete receptor 차단제인 propranolol $4{\times}10^{-6}M$에 의해 차단되었다. 또한 Epi의 PD 및 SCC 증가효과는 propranolol $4{\times}10M$에 의하여 강화됨을 볼 수 있었다. 4. Alpha 2 adrenoceptor agonist인 clonidine 및 guanabenz도 PD 및 SCC의 증가를 가져왔으며 이러한 효과는 alpha 2 receptor 차단제인 yohimbine에서 보다 Alpha 1 receptor 차단제인 prazosin에 의해 더 잘 억제되었다. 이상 실험의 결과 개구리 복부피부에도 포유동물에서와 같이 adrenergic alpha 및 beta receptor가 존재하며 alpha receptor는 PD 및 SCC의 증가를, beta receptor는 PD 및 SCC의 감소를 매개하여, 개구리 피부의 Na 수송에 있어 adrenergic system이 중요한 조절작용을 하고 있음을 알 수 있었다. 그러나 여기에 관여하는 alpha receptor는 다른 포유류에서와 같이 alpha 1 및 alpha 2 adrenoceptor로 구분할 수는 없었다.

• 한국임상수의학회지
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• 제23권4권
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• pp.421-426
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• 2006

The effects of transmural nerve stimulation induced releasing neurotransmitters on the changes of swine uterine smooth muscle motility were examined by polygraph through isometric force transducer. The frequency dependent relaxation and rebound contraction were revealed on precontraction with histamine by transmural nerve stimulation. The rebound contraction by transmural nerve stimulation was inhibited by nonselective ${\alpha}$-adrenergic receptor antagonist, phentolamine, and the relaxation by transmural nerve stimulation was blocked by nonselective ${\beta}$-adrenergic receptor antagonist, propranolol. The relaxation induced by nonselective ${\beta}$-adrenergic receptor agonist, isoproterenol on precontraction with histamine were the dose dependent manner and this relaxation was blocked by nonselective ${\beta}$-adrenergic receptor antagonist, propranolol in isolated uterine smooth muscle of pig. These results suggest that endogenous neurotransmitters on smooth muscle relaxation was influenced by ${\beta}$-adrenergic receptor in swine.

• Archives of Pharmacal Research
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• 제12권4호
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• pp.282-288
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• 1989

This study was investigated the effects of imipramine (IMI) and electroconvulsive shock (ECS), which are used as antidepressant therapy, on the central $\beta_1$or $\beta_2$ adrenergic receptor in anesthetized rats. The resting blood pressure and heart rate decreased in reserpinized group (5 mg/kg i. p., 24 hr before), but not in order 4 groups i. e. acute IMI (20 mg/kg i. p.. 3-5 hr before), chronic IMI (Same dose, twice a day for 14 days), siggle ECS (sinusoidal 20 Hz, 120 V for 2 sec) and repeated ECS (same condition, daily for 12 days). The increase of heart rate and hypotension evoked by 1 or 3 $\mu$g intracerebroventricular (i. c. v.) administration of (+) dobutamine, $\beta_2$-agonist, 1 or 3 $\mu$g i. c. v. was significantly attenuated in repeated ECS or reserpine treatment. And, the diminuation of pulse pressure of salbutamol also reduced by repeated ECS. These results suggest that IMI or ECS result in attenuation on tachycardia by (+) dobutamine or on hypotension by salbutamol, presumably by which the central $\beta_1$ or $\beta_2$receptor sensitivity may be suppressed, repectively.

• Archives of Pharmacal Research
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• 제9권4호
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• pp.219-222
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• 1986

Dose-dependent increasesin blood glucose were produced by epinephrine and clonidine in fasted male mice. Isoproterenol was ineffective in increasing blood glucose at lower doses ($10^{-8}M$/kg-$10^{-7}M$/kg); with higher dose ($10^{-6}M$/kg) the glucose level was increased. The hyperglycemia induced by epinephrine was inhibited by yobimbine, prazosin and propranolol, indicating that the hyperglycemic effect of epinephrine is mediated by alpha-1, alpha-2 and beta adrenoceptor. When clonidine (10$^{-6}$ M/kg) was administered simultaneously with sioproterenol ($10^{-6}M$/kg), an enhenced hyperglycemic effect was observed. The increment produced by clonidine plus isoproterenol was higher than that by clonidine alone. These increment produced by clonidine plus isoproterenol was higher than that by clonidine alone. These results suggest that stimulation of alpha-2 adrenoceptor may be reponsible for the exertion of the hyperglycemic effect by beta agonists in fasted mice.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.237-238
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• 1989

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2000년도 정기총회 및 제25차 춘계학술발표회
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• pp.132-132
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• 2000

• Animal cells and systems
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• 제4권1호
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• pp.71-76
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• 2000

The aim of this study was to investigate expression patterns of the prolactin (PRL) and c-fos genes by 17$\beta$-estradiol (17$\beta$-E) and stress in the mouse pituitary. In the pituitary, the levels of PRL mRNA were found high with some fluctuation at 30, 50, and 90 min whereas the levels of PRL mRNA were low at 120 min when ovariectomized female mice were injected with 17$\beta$-E or vehicle. PRL mRNA levels began to increase again at 4 h and remained high up to 24 h only in the 17$\beta$-E- treated mice. The overall changes in c-fos mRNA by 17$\beta$-E were very similar to those in PRL mRNA in the pituitary. Subsequent study revealed that these high initial levels of PRL and c-fos mRNAs were caused by stress during Injection, not by 17$\beta$-E, since vehicle injection alone into the ovariectomized mice could increase the levels of PRL and c-fos mRNAs. The stress-induced elevations of PRL and c-fos mRNAs were inhibited by bromocriptin, a dopamine agonist, suggesting that the dopaminergic system is involved in the action route of injection stress. In addition, the induced levels of c-fos mRNA by 17$\beta$-E and stress in the pituitary were very low compared with those in the uterus. The time course changes in c-fos mRNA level were different between the pituitary and uterus. Taken together, these data indicate that PRL and c-tos gene expression in the pituitary are regulated by 17$\beta$-E and stress in a parallel manner, supporting the notion that c-Fos plays a role in regulation of PRL gene expression.