• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.292-292
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• 1994

Catecholamines acting through ${\beta}$-adrenergic receptors regulate a wide range of metabolic activities in mammalian tissue. Of the various receptors coupled to adenylate cyclase, the ${\beta}$-adrenergic receptors are the most extensively characterized and have been purified from both nonmammal ian and mammal inn sources. However, most studies of the molecular properties of ${\beta}$-adrenergic receptors have been confined to peripheral tissues. Less progress has been achieved in characterizing the brain ${\beta}$-adrenergic receptor The goal of the present study was, therefore, to purify and characterize the neurotransmitter receptor proteins. To achieve this goal, the following stepwise experiments were performed. At first, the membrane-bound ${\beta}$-adrenergic receptors were. solubi1ized from brain tissue. Secondly, conditions for affinity chromatography were determined to purify the solubilized receptors effectively. Finally, the large-scale purification was performed and the characteristics of the purified ${\beta}$-adrenergic receptor were examined.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.1-8
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• 1993

It has been known that calcium antagonists also inhibit the radioligand binding to muscarinic and $\alpha$-adrenergic receptors and, in case of verapamil, these inhibitions may play a role in the effects of verapamil on the heart. In this study, the effects of nicardipine, nifedipine, nimodipine, diltiazem and verapamil on the binding of [$^3H$]dihydroalprenolol (DHA) to dog cardiac ${\beta}$-adrenergic receptors were examined. A single uniform [$^3H$]DHA binding site ($K_D/= 5nM\;and\;B_{max}=2600$ fmol/mg protein) was identified in dog cardiac sarcolemma. [$^3H$]DHA binding was not affected by the usual therapeutic concentrations of these calcium antagonists (nanomolar range) but in the "nonspecific"concentration ranges ($28-180{\mu}m$) these drugs inhibited [$^3H$]DHA binding to $\beta$-adrenergic receptors. Nicardipine, nifedipine, nimodipine and diltiazem competed for [$^3H$]DHA binding to ${\beta}$-adrenergic receptors with dissociation constants ($K_i$) of $28{\mu}m,\' 74{\mu}m, 39{\mu}m \;and \;35{\mu}m,$ respectively. Verapamil ($K_i=176.5 {\mu}m$) was less potent inhibitor than other drugs and this inhibition was noncompetitive; the maximal binding capacity ($B_{max}$) $300 {\mu}m$ verapamil without change in the apparent dissociation constant (4K_D$) for DHA. These results indicate that the inhibitory action of calcium antagonists at high concentrations on ${\beta}$-adrenergic receptors is not involved in the therapeutic effects of these drugs by the calcium channel blocking action.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.161-167
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• 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.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.617-622
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• 1993

The preliminary studies on the localization of adrenoceptors were performed on smooth muscle strips of bovine esophageal groove. The mechanical activity of the muscle strip was recorded isometrically in vitro.w In the bottom circular muscle strips. the excitatory ${\alpha}-adrenergic$ responses were not blocked by tetrodotoxin$(2.1{\times}10^{-6}M)$ and denervation which was carried by cold storage of strips for 48 hrs in Tyrode's solution at $5-6{^{\circ}C}$ without oxygen supply. These excitatory ${\alpha}-adrenergic$ responses were partially blocked by atropine. In the lip longitudinal muscle strips, the inhibitory${\beta}-adrenergic$ responses were not blocked by pretreatment of tetrodotoxin and atropine. The results suggest that ${\beta}-adrenergic$ receptors mediating relaxations are located on the postsynaptic smooth muscle cells, whereas ${\beta}-adrenergic$ receptors mediating contractions are located both in the smooth muscle cells and in the cholinergic neurones.

• Journal of Korean Biological Nursing Science
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• v.10 no.1
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• pp.80-87
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• 2008

Purpose: Hypoestrogenism caused by ovariectomy, disease, or menopause is associated with increased obesity in women. Altered fat distribution and weight gain are consequences of menopausal hypoestrogenism, but the mechanisms responsible are not completely known. This study examined the effect of estrogen on obesity in ovariectomized rats. Method: The groups of female rats were 4 weeks post ovariectomy (OVX) or, 4 weeks post-sham operation (SHAM), and 2 weeks post ovariectomy followed by 2 weeks replacement with estradiol benzoate (ER-$16{\mu}g$/kg, subq, qd). Serum ghrelin level was measured by radioimmunoassay (RIA). The expression of adrenergic receptors in adipose tissue was measured by Western blotting assay. Result: OVX significantly increased body weight, serum cholesterol. Two weeks estrogen replacement reduced body weight accompanied by the increment of serum ghrelin and the reduction of the receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$. Conclusion: We provide evidence that estrogen reduces obesity through the altered receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$ in adipose tissue in ovariectomized rats.

• YAKHAK HOEJI
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• v.32 no.6
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• pp.428-434
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• 1988

The effects of calcium and calcium antagonist, nifedipine on the adrenergic receptor-stimulated glycogenolysis were investigated in isolated rat hepatocytes. The hepatic glycogenolysis induced by alpha-adrenergic receptor stimulation depended on calcium ions, and beta-adrenergic activation was unrelated to calcium ions. Nifedipine decreased the alpha-adrenergic agonist-induced glucose release significantly and the decrease was depended on calcium ions. The glucose release induced by beta-adrenergic agonist was not inhibited by nifedipine.

• Environmental Mutagens and Carcinogens
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• v.21 no.2
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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.

• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.41-48
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• 1966

The author studied the adrenotropic receptors of the non-pregnant uteri of the rabbit and rat, using epinephrine (alpha and beta activator), phenoxybenzamine(alpha blocking agent) and nethalide (beta blockade), and obtained the following results: 1. The spontaneous motility of isolated non-pregnant uteri from rabbits were stimulated by epinephrine, whereas that of isolated non-pregnant rat uterus was inhibited by epinephrine. 2. Both alpha and beta adrenergic receptors were present in the uterine muscle of both animals. 3. In the non-pregnant rabbit uterus, alpha receptors were predominant, whereas in the non -pregnant rat uterus, beta receptors preponderated over alpha receptors.

• Clinical and Experimental Emergency Medicine
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• v.3 no.3
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• pp.175-180
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• 2016

Objective Combination of ${\beta}_1-adrenergic$ receptor (AR) blockade and ${\beta}_2-AR$ activation might be a potential novel therapy for treating heart failure. However, use of ${\beta}-AR$ agonists and/or antagonists in the clinical setting is controversial because of the lack of information on cardiac inotropic or chronotropic regulation by AR signaling. Methods In this study, we performed hemodynamic evaluation by examining force frequency response (FFR), Frank-Starling relationship, and response to a non-selective ${\beta}-AR$ agonist (isoproterenol) in hearts isolated from 6-month-old transgenic (TG) mice overexpressing ${\beta}_1-$ and ${\beta}_2-ARs$ (${\beta}_1-$ and ${\beta}_2-AR$ TG mice, respectively). Results Cardiac physiologic consequences of ${\beta}_1-$ and ${\beta}_2-AR$ overexpression resulted in similar maximal response to isoproterenol and faster temporary decline of positive inotropic response in ${\beta}_2-AR$ TG mice. ${\beta}_1-AR$ TG mice showed a pronounced negative limb of FFR, whereas ${\beta}_2-AR$ TG mice showed high stimulation frequencies with low contractile depression during FFR. In contrast, Frank-Starling relationship was equally enhanced in both ${\beta}_1-$ and ${\beta}_2-AR$ TG mice. Conclusion Hemodynamic evaluation performed in the present showed a difference in ${\beta}_1-$ and ${\beta}_2-AR$ signaling, which may be due to the difference in the desensitization of ${\beta}_1-$ and ${\beta}_2-ARs$.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.95-95
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• 1997

Among the various receptor molecules discovered so far the ${\beta}$2-adrenergic receptors have been regarded as excellent model systems for the so called 7 transmembrane helix receptor and have been the focus of extensive studies. For the analysis of receptor structure and function a monoclonal antibody plays a crucial role, thus providing useful tools for the study of receptor. However, because of the minute quantity of receptor molecules which could be obtained from natural sources, the generation of specific monoclonal antibody against receptor molecules from the purified receptors has been regarded as virtually impractical in consideration of cost and experimental times. The purpose of the present study was to generate and characterize a monoclonal antibody against human ${\beta}$2-adrenergic receptor. For the production of antibody, C-terminal regions of the human ${\beta}$2-adrenergic receptor was produced as a fusion protein with Glutathion S-transferase (GST) in E. Coli. The expression of the fusion protein was identified by SDS-PAGE and Western blot using monoclonal anti-GST antibody. The fusion protein was purified to an apparent homogeniety by affinity chromatography with Glutathion Sepharose CL-4B and used as an antigen for the immunization of BALB/C mice. The Production of monoclonal antibody was achieved by fusion of the immunized spleen cells and SP/2-0 myeloma cells. Positive hybridomas were screened by ELISA and were cloned by two consecutive rounds of limiting dilution. The monoclonal antibody produced in this study (mAb${\beta}$C02) was IgM type and purified by immunoaffinity chromatography using anti-mouse IgM agarose as an affinity matrix. MAb${\beta}$C02 showed strong and specific immunoreactivity against both the fusion protein and human ${\beta}$2-adrenergic receptor in ELISA and Western blot. The molecular weight of immunoreactive band was 64 kDa and exactly coincided with the previously reported molecular weight of ${\beta}$2-adrenergic recepters. The results of the present study suggest that mAb${\beta}$C02 may be used for the study of receptor function and regulation in normal or nonphysiological status.