• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.29-29
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• 2003

Compartmentation of intracellular signaling pathways serves as an important mechanism conferring the specificity of G protein-coupled receptor (GPCR) signaling. In the heart, stimulation of $\beta$$_2$-adrenoceptor ($\beta$$_2$-AR), a prototypical GPCR, activates a tightly localized protein kinase A (PKA) signaling, which regulates substrates at cell surface membranes, bypassing cytosolic target proteins (eg, phospholamban). Although a concurrent activation of $\beta$$_2$-AR-coupled $G_{i}$ proteins has been implicated in the functional compartmentation of PKA signaling, the exact mechanism underlying the restriction of the $\beta$$_2$-AR-PKA pathway remains unclear. In the present study, we demonstrate that phosphatidylinositol 3-kinase (PI3K) plays an essential role in confining the $\beta$$_2$-AR-PKA signaling. Inhibition of PI3K with LY294002 or wortmannin enables $\beta$$_2$-AR-PKA signaling to reach intracellular substrates, as manifested by a robust increase in phosphorylation of phospholamban, and markedly enhances the receptor-mediated positive contractile and relaxant responses in cardiac myocytes. These potentiating effects of PI3K inhibitors are not accompanied by an increase in $\beta$$_2$-AR-induced cAMP formation. Blocking $G_{i}$ or $G_{$\square$$\square$}$ signaling with pertussis toxin or $\beta$ARK-ct, a peptide inhibitor of $G_{$\square$$\square$}$, completely prevents the potentiating effects induced by PI3K inhibition, indicating that the pathway responsible for the functional compartmentation of $\beta$$_2$-AR-PKA siglaling sequentially involves $G_{i}$, $G_{$\square$$\square$}$, and PI3K. Thus, PI3K constitutes a key downstream event of $\beta$$_2$-AR- $G_{i}$ signaling, which confines and negates the concurrent $\beta$$_2$-AR/Gs-mediated PKA signaling.gnaling.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2008-2014
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• 2011

Serotonin or 5-hydroxytryptamine subtype 2C ($5-HT_{2C}$) receptor belongs to class A amine subfamily of G-protein-coupled receptor (GPCR) super family and its ligands has therapeutic promise as anti-depressant and -obesity agents. So far, bovine rhodopsin from class A opsin subfamily was the mostly used X-ray crystal template to model this receptor. Here, we explained homology model using beta 2 adrenergic receptor (${\beta}$2AR), the model was energetically minimized and validated by flexible ligand docking with known agonists and antagonists. In the active site Asp134, Ser138 of transmembrane 3 (TM3), Arg195 of extracellular loop 2 (ECL2) and Tyr358 of TM7 were found as important residues to interact with agonists. In addition to these, V208 of ECL2 and N351 of TM7 was found to interact with antagonists. Several conserved residues including Trp324, Phe327 and Phe328 were also found to contribute hydrophobic interaction. The predicted ligand binding mode is in good agreement with published mutagenesis and homology model data. This new template derived homology model can be useful for further virtual screening based lead identification.

• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.37-60
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• 1983

The uterus receives adrenergic terminals from the mesenteric ganglia and considerably large amount of catecholamines have been shown to be contained in this organ. On the other hand, the activities of epinephrine, norepinephrine or adrenergic nerve on uterine motility is so complicated that many controversial results have been reporter. Recently, a large number of reports concerning the changes of uterine catecholamines content have appeared, but little is known about the role of uterine catecholamines in their activities on uterine motility. The present experiments were undertaken to determine the significance of the intrinsic uterine catecholamines in the physiology of uterus. Female albino rabbits weighing approximately 2 kg were employed in this experiment. uterine strip3 were prepared and suspended in a constant temperature $bath(38^{\circ}C)$ containing 100 ml of Locke's solution aerated with 95% oxygen and 5% carbon dioxide. Spontaneous motility was recorded on a smoked drum with an isotonic lever. The catecholamines concentration of the uterus was determined according to the Procedure described of Shore and Olin (1958). Human uterus obtained from patients was also used to determine the catecholam ines content of myometrium. Followings are summarized results. 1) On the non-pregnant rabbit uterine strips, epinephrine and norepinephrine significantly elevated the tonus and stimulated the spontaneous motility. Pretreatment with dichloroisoproterenol(DCI), an adrenergic beta-receptor blocker, enhanced the stimulatory activity of epinephrine or norepinephrine. On the other hand, pretreatment with dibenamine, an adrenergic alpha-receptor blocker, rendered the uterine muscle to exhibit inhibition after the administration of epinephrine or norepinephrine. Following the treatment with both DCI and dibenamine, epinephrine or norepinephrine produced no appreciable effects on the spontaneous motility of the uterus. These results suggest there exist both alpha and beta-adrenergic receptors in the uterine muscle and the response to epinephrine of the former is predominant over that of latter in the non-pregnant uterus of rabbits. The total catecholamines concentration of the non-pregnant uterus was $351\;m{\mu}g/g$ and the fractional concentrations of epinephrine and norepinephrine were $125\;m{\mu}g/g(35.7%)$ and $226\;m{\mu}g/g$ respectively. It is interesting to note that the catecholamines content of uterus was characterized by a high fractional corcentration of epinephrine relative to norepinephrine. 2) On the pregnant rabbit uterine strips, the effects of epinephrine and norepinephrine varied according to the period of pregnancy. The response to epinephrine of adrenergic beta receptor of uterus increased during pregnancy, and the effect of catecholamine was inhibitory in the early pregnancy but became stimulatory as the pregnancy progressed. This stimulating action on the uterine motility was found to occur through the action of norepinephrine. The uterine catecholamines concentration was markedly reduced during pregnancy. The catecholamines concentration was started to decrease in the early pregnancy, reached the lowest level in the mid-pregnancy and then started to increaae again in the late pregnancy when the total catecholamines content became the highest level of all. This increase of catefholamines in late pregnancy was chiefly due to the increase of norepinephrine. These results suggest that the uterine motility may be related to the catecholamines content, especially norepinephrine content in the uterus. 3) Bilateral oophorectomy of rabbits results in a marked shrink of the uterus in size. The spontaneous motility of the uterine segment of these animals was very weak and irregular. Norepinephrine produced inhibitory effect, whereas epinephrine was stimulatory or inhibitory effect on the uterine segment. The total catecholamines tontent in whole uterus was markedly reduced. The injection of estrogen into the oophorectornized rabbit increased the weight of uterus to approximately three times of that of oophorectornized animal. The apontaneous motility and the response to epinephrine and norepinephrine of the uterine segment were greatly enhanced. Both epinephrine and norepinephrine produced a marked stimulatory effects of the uterine motility. The uterine content of catecholamines, particularly epinephrine, was markedly increased. The injection of progesterone into the oophorectornized rabbit increaeed the weight of uterus to approximately 2.5 times of that of eophorectornized animal. The spontaneous motility of the uterine segment was weak and irregular. Epinephrine produced stimulatory effect at high concentrations but norepinephrine always prcdnced inhibitory effect on the uterine segment. The uterine content of catecholamines, particularly of norepinephrine, was markedly reduced. These results suggested that ovarian hormones play an important role not only on the growth and spontaneous norepinephrine of uterus but also on the catecholamines content and responee to epinephrine and norepinephrine of the uterus. 4) The intraperitoneal injection of reserpine(3 mg/kg) into the non-pregnant, pregnant and oophorectornieed rabbits markedly decreased the uterine content of catecholamines, particularly of the norepinephrine. The stimulatory response to epinephrine and. norepinephrine of the uterine segment of these reserpinized ratbits was markedly reduced whereas the inhibitory response to these catecholamines was enhanced. This finding further support the close relationship between the uterine catecholamines content and uterine response to epineptrire and norepinephrine. 5) In the human uterus, the concentration of epinephrine was actrally greater than that of norepinephrine and it was significantly greater during the proliferative phase of the menstrtal cycle. In the human pregnant uterus, the concentrations of toth epinephrine and ncrefinephrine were markedly reduced and showed about 45 percent rednction after 6-8 weeks of ectopic Pregnancy. At full term ana during labor, the concentrations of epinephrine and norepinephrine at placental sites were less than those found in the non-pregnant group. Of interest was the finding that the norepinephrine concentration of uterus from toxemic patients was two and half times higher than that of lower uterine segment of the nontoxemic pregnant individuals. Also the epinephrine concentraticn was slightly increaeed.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.285-293
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• 1998

Yuldahansotang(YH) has been used in Sasang(四象) constitution medicine for many years as a therapeutic agent for cerebral disease. The effect of YH on the vascular system is not known. The purpose of this study was to determine the effect of YH on blood pressure, regional cerebral blood flow(rCBF) and pial arterial diameter of rats. 1. Blood pressure decreased by YH in rats. 2. rCBF was increased by YH in a dose-dependent manner. 3. Pretreatment with propranolol, methylene blue and indomethacin significantly inhibited YH induced increase in rCBF. 5. Blood pressure increased by Radix Puerariae(RP) and Radix Ligustici Tenuissimae(RLT) but Radix Scutellariae(RC) decreased blood pressure in rats. 6. rCBF was increased by RP and RLT in a dose-dependent manner but RC decreased low dosage, and RC increased high dosage. 7. Pial arterial diameter was increased by YH in a dose-dependent manner. 8. Pretreatment with propranolol significantly inhibited the increased in pial arterial diameter induced by YH. These results suggest that YH causes a diverse response of blood pressure, regional cerebral blood flow(rCBF) and pial arterial diameter. The increase in rCBF is also mediated by prostaglandins, cyclic GMP and adrenergic ${\beta}$ receptor and the increase in pial arteral diameter is mediated by adrenergic ${\beta}$ receptor.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.5
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• pp.460-469
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• 2019

Purpose: The ${\beta}3-adrenergic$ receptor (ADRB3) is expressed in visceral adipose tissue and has been speculated to contribute to lipolysis, energy metabolism, and regulation of the metabolic rate. In this study, we aimed to investigate the association of polymorphism of the ADRB3 gene with the sex of children with obesity and related pathologies. Methods: ADRB3 gene trp64arg genotyping was conducted in 441 children aged 6-18 years. Among these subjects, 264 were obese (103 boys; 161 girls) and 179 were of normal weight (81 boys; 98 girls). In the obese group, fasting lipids, glucose and insulin levels, and blood pressure were measured. Metabolic syndrome (MS) was defined according to the modified World Health Organization criteria adapted for children. Results: The frequency of trp64arg genotype was similar in obese and normal weight children. In obese children, serum lipid, glucose, and insulin levels; homeostasis model assessment of insulin resistance (HOMA-IR) scores; and MS were not different between arg allele carriers (trp64arg) and noncarriers (trp64trp). In 264 obese children, genetic analysis results revealed that the arg allele carriers were significantly higher in girls than in boys (p=0.001). In the normal weight group, no statistically significant difference was found between genotypes of boys and girls (p=0.771). Conclusion: Trp64arg polymorphism of the ADRB3 gene was not associated with obesity and MS in Turkish children and adolescents. Although no relationships were observed between the genotypes and lipids, glucose/insulin levels, or HOMA-IR, the presence of trp64arg variant was frequent in obese girls, which can lead to weight gain as well as difficulty in losing weight in women.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.83-90
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• 2004

This study was conducted to examine the effects of $\beta$3-adrenergic receptor polymorphism on the blood glucose level and obesity in 530 volunteers, who attended a weight loss program in a local obesity clinic. The age differences in total subjects and the distribution of male and female were 26.55$\pm$0.31 yr, 9.1% (n=48), 90.9% (n=492). The genotype distribution of $\beta$3-AR gene polymorphism were WW type 75%, WR type 22% and RR type 3%. Among many parameters, fasting blood glucose was significantly higher in WR＋RR type (p=0.001) compared with WW type. When the subjects were divided into two groups by 6.105 mmol/L of the fasting blood glucose level, the frequency of hyperglycemia was 23.3% in WW type subjects, while there was a increase to 35.6% in WR＋RR type subjects (p=0.011, $\chi$$^2$-analysis). When hyperglycemia group was compared with normoglycemia group, obesity index (p=0.044), %body fat (p=0.046) and TG (p=0.000) were significantly higher, and HDL (p=0.006) was significantly lower in the hyperglycemia. When all of the above factors were included in stepwise logistic regression analysis to find risk factors of hyperglycemia, the results were that the odds ratio for hyperglycemia were 2.015 (p=0.011) for WR+RR type of $\beta$3-AR gene, 2.165 (p=0.000) for TG and 0.419 (p=0.059) for HDL cholesterol. There was a significantly positive correlation between the blood glucose vs BMI, WHR, body fat in the WW type (r=0.099, 0.119, 0.082) However, in the WR and RR type there were no significance between the blood glucose vs BMI, WHR, body fat. These data suggest that the WR＋RR genotype of $\beta$3-AR has a very strong association with increased blood glucose level and might be a significant risk factor for hyperglycemia among Korean subjects.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.493-500
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• 1994

The purpose of this study was to investigate the effects of neurotransmitters and the source of $Ca^{2+}$ in the effects of neurotransmitters on the motility of pig oviductal isthmic smooth muscle. The motility of the isolated smooth muscle was recorded by using physiological recording system. The results were summarized as follows; Acetylcholine, norepinephrine, histamine and prostaglandin $F_{2{\alpha}}(PGF_{2{\alpha}})$ caused the contraction and the contractile responses were increased in a dose-dependent manner from the concentration of $10^{-7}$ to $10^{-4}M$. The maximum contractility of acetylcholine, norepinephrine, histamine and $PGF_{2{\alpha}}$ was 65.99, 28.66, 83.99 and 47.33% of 100 mM K contraction, respectively. The contractile response induced by acetylcholine$(10^{-6}M)$ was completely blocked by the pretreatment with cholinergic receptor blocker, atropine$(10^{-6}M)$, the contractile response induced by norepinephrine$(10^{-5}M)$ was blocked by the pretreatment with ${\alpha}$-adrenergic receptor blocker, phentolamine$(10^{-6}M)$ but was not blocked and rather increased by the pretreatment with ${\beta}$-adrenergic receptor blocker. propranolol$(10^{-6}M)$, the contractile response induced by histamine$(10^{-6}M)$ was completely blocked by the pretreatment with $H_1$-histaminergic receptor blocker, pyrilamine$(10^{-6}M)$ but was increased by the pretreatment with $H_2$-histaminergic receptor blocker, cimetidine$(10^{-6}M)$. The contractile response induced by acetylcholine$(10^{-6}M)$, norepinephrine$(10^{-5}M)$ and histamine$(10^{-6}M)$ was weakly contracted response in $Ca^{2+}$-free medium, but the contractile response induced by $PGF_{2{\alpha}}(10^{-6}M)$ was disappeared. The contractile response induced by acetylcholine$(10^{-6}M)$, norepinephrine$(10^{-5}M)$ and histamine$(10^{-6}M)$ was powerfully depressed by the pretreatment with $Ca^{2+}$-channel blocker, verapamil$(10^{-5}M)$ but the contractile response induced by $PGF_{2{\alpha}}(10^{-6}M)$ was completely inhibited.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.25-29
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• 1980

Etomidoline ($Nonspa^{\circledR}$), which is chemically related to tertiary amine, is new synthetic antispasmodic agent with analgesic action. Antispasmodic effect of this agent is stronger than hyoscine butylbromide ($Buscopan^{\circledR}$), quaternary amine, and the absorption from intestine is also much higher. This study was undertaken to determine the effect of etomidoline on duodenal motility and other smooth muscles of rabbit. Strips of various isolated smooth muscle, 2 cm long from adult rabbits weighting about 2 kg, were suspended in a muscle chamber containing Tyrode's solution, which was bubbled with oxygen gas, and the temperature of the solution was kept constant at $38^{\circ}C$. After being washed with fresh solution several times the strips of smooth muscle attained constant motility and tonus. Etomidoline and other drugs were added in various concentrations to the chamber. Contractility of the strips was measured by using polygraph (Grass, model 7). The results are as follows: 1) In isolated rabbit atrium etomidoline produces a slight depression of contractility and the rate is also decreased. 2) On the other hand, etomidoline relaxed isolated strips of stomach, duodenal, and detrusor of rabbit. This relaxing effect of etomidoline on isolated duodenal strip of rabbit was not blocked by ${\alpha}$-adrenergic blocking agent, phenoxybenzamine, but by ${\beta}$-adrenergic blocking agent, propranolol. 3) Etomidoline did not exert any effect on isolated aorta, gall bladder, and trigone of rabbit. From the above results, it may be concluded that the relaxing effect of etomidoline on duodenal strip is related ${\beta}$-adrenergic receptor.

• BMB Reports
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• v.31 no.2
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• pp.123-129
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• 1998

Foreign proteins, $endo-{\beta}-1,4-glucanase$ of Bacillus subtilis, preS1+S2 region of hepatitis B virus large surface antigen, human ${\beta}_2-adrenergic$ receptor ($h{\beta}_{2}AR$), and bovine growth hormone (bGH) were expressed in Saccharomyces cerevisiae and secreted into the medium. These proteins were expressed using the alcohol dehydrogenase I (ADH1) promoter of Saccharomyces cerevisiae and secreted by signal sequence of the 97 K killer toxin gene of doublestranded linear DNA plasmid (pGKL1) of S. cerevisiae. All these proteins underwent severe modifications; in particular, N-glycosylation in the case of $endo-{\beta}-1,4-glucanase$, $h{\beta}_2AR$, and preS1+S2. Seventy four percent of the expressed $endo-{\beta}-1,4-glucanase$ was secreted into the culture medium. Highly modified proteins were detected in the culture medium and in the cell. Expressed $h{\beta}_2AR$, which has seven transmembrane domains, remained in the cell. The degrees of secretion and modification and the states of proteins in the culture medium and in the cell were quite different. These results indicated that the nature of the protein has a critical role in its secretion and modifications.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.77-89
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• 1998

Background: Genetic and environmental factors are known to affect the incidence and severity of asthma. Stimulation of $\beta_2$-Adrenergic Receptor ($\beta_2$AR) results in smooth muscle relaxation, leading to decrease in resistance of airflow. The gene encoding the $\beta_2$AR has recently been seguenced. The $\beta_2$AR genotype at the polymorphic loci of codons 16, 27, 34, and 164 was known to cause changes in the amino acids. The relationships between the structure of the $\beta_2$AR and its functions are being elucidated. Purpose : The gene encoding the $\beta_2$AR was carried out to assess the frequency of polymorphisms in bronchial asthma, to determine wheather these polymorphisms have any relation to the severity, or nocturnal symptoms in bronchial asthma. Methods: The subjects studied were 103 patients with bronchial asthma, which consisted of 30 mild episodic, 32 mild persistent, 17 moderate, and 24 severe asthma patients. The polymorphisms of the $\beta_2$AR gene were detected by mutated allele specific amplification (MASA) method at the codons 16,27,34, and 164. Results: The most frequent polymorphism was arginine 16 to glycine. The other two polymorphisms, valine 34 to methionine and glutamine 27 to glutamic acid occured in 11 and 6 patients respectively. The polymorphism of threonine 164 to isoleucine was not found in our enrolled patients. The homozygous polymorphism of $\beta_2$AR gene was found in only arginine 16 to glycine (12.6%). The heterozygous polymorphisms of $\beta_2$AR gene were in arginine 16 to glycine, valine 34 to methionine, and glutamine 27 to glutamic acid, as 65.1 %,10.7%, and 5.8% respectively in asthma patients. The presence of agrginine 16 to glycine heterozygous or/and homozygous polymorphism was associated in severe asthma (p=0.015), but there was no association between the other three polymorphisms and the severity of asthma. The frequency of the $\beta_2$AR gene polymorphisms was no relation in nocturnal asthma as compared with non-nocturnal asthma. Conclusion: The arginine 16 to glycine polymorphism of the $\beta_2$AR gene is the most frequently found in asthma patients and association with severe asthma. But there was no association between the polymorphism of the $\beta_2$AR gene and nocturnal asthma.