• Journal of fish pathology
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• v.9 no.1
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• pp.41-51
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• 1996

The present study was undertaken to investigate the physiological characteristics of the adrenergic responses in the tilapia dorsal aorta. Epinephrine, norepinephrine, clonidine and methoxamine in the presence of propranolol($3{\times}10^{-6}$M), induced only endothelium-independent and concentration-dependent vasocontractions in tilapia dorsal aorta. The rank order of potency of adrenergic agonists inducing vasocontraction was epinephrine>norepinephrine>phenylephrine>clonidine>ethoxamine, Yohimbine produced a parallel shift of the concentration-vascontraction curves of epinephrine, norepinephrine, phenylephrine and clonidine to the right, while prazosin depressed the maximum responses of epinephrine and norepinephrine. Calcium-free physiological solution and verapamil markedly reduced epinephrine or norepinephrine-induced vasocontractions. These results suggest that a-adrenergic agonists produce only on endothelium-inedpenent casoconstrictions in tilapia dorsal aorta and these effect of a-adrenergic agonists, which might be associated with both calcium release from intracellular stores and calcium influx through voltage-dependent calcium channel.

• Journal of the Korean Society of Food Culture
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• v.26 no.4
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• pp.364-373
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• 2011

The purpose of this study was to investigate the body composition, biochemical parameters, and consumption of convenience foods according to ${\beta}$-3 adrenergic receptor polymorphism in university students. A survey was conducted on a total of 486 students - 189 males and 297 females. Based on a self-reporting method, questionnaires were administered for over 20 minutes, and ${\beta}$-3 adrenergic receptor and blood samples were also analyzed. The genotype frequencies of ${\beta}$-3 adrenergic receptor polymorphism were Trp/Trp homozygote (73.0%) and Trp/Arg heterozygote (27.0%) in male students. For the female students, the distribution of genotypes was Trp/Trp (71.0%) and Trp/Arg (29.0%). There were no differences according to biochemical parameters (ALT, cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, and hemoglobin) or body composition. Males with TT genotype frequently ate Ramyon (2.40${\pm}$0.52), Cup Ramyon (2.37${\pm}$0.39), Kimchi (2.23${\pm}$0.61), and frozen meat (2.00${\pm}$0.44), whereas males with TA genotype ate Fries (frozen food) (1.90${\pm}$0.79), Smoked meat (1.67${\pm}$0.81), and Canned fruit (1.64${\pm}$0.81). Females with TT genotype frequently ate Frozen fries (2.21${\pm}$0.35), Kimbab (2.12${\pm}$0.44), and Ramyon (1.85${\pm}$0.40), whereas females with TA genotype frequently ate Kimchi (1.73${\pm}$0.98), Fries (frozen food) (1.46${\pm}$0.26), and Cup Ramyon (1.30${\pm}$0.34). When questioned about satisfaction about body shape, 22.8 and 60.8% of those with TT genotype answered that they were 'satisfied' or needed to 'lose weight', respectively, whereas 18.0 and 63.9% of those with TA genotype answered that they were 'satisfied' or needed to 'lose weight', respectively. In conclusion, this study found no significant effects in terms of ${\beta}$-3 adrenergic receptor polymorphism, which suggests that health-promoting education needs to be developed so that university students appropriately recognize their bodies and control their weight in desirable ways. Therefore, it is necessary to educate individuals with TT genotype how to buy reasonable foods by understanding the interrelationship between convenience foods and health care and by checking the nutrition index labels on convenience foods. Thus, it is recommended that a health-promoting program be developed for the promotion of healthy lifestyles.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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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.

• Biomolecules & Therapeutics
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• v.25 no.1
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• pp.44-56
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• 2017

Insulin resistance is characterized by the reduced ability of insulin to stimulate tissue uptake and disposal of glucose including cardiac muscle. These conditions accelerate the progression of heart failure and increase cardiovascular morbidity and mortality in patients with cardiovascular diseases. It is noteworthy that some conditions of insulin resistance are characterized by up-regulation of the sympathetic nervous system, resulting in enhanced stimulation of ${\beta}$-adrenergic receptor (${\beta}$AR). Overstimulation of ${\beta}$ARs leads to the development of heart failure and is associated with the pathogenesis of insulin resistance in the heart. However, pathological consequences of the cross-talk between the ${\beta}$AR and the insulin sensitivity and the mechanism by which ${\beta}$AR overstimulation promotes insulin resistance remain unclear. This review article examines the hypothesis that ${\beta}$ARs overstimulation leads to induction of insulin resistance in the heart.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.394-400
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• 1991

A question whether abnormal responsiveness of hypothalamic catecholaminergic nervous system to ovarian steoid hormones in spontaneously hypertensive rats (SHR) exist was investigated. Four groups of experimental animals were prepared for SHR and normotensive Wistar rats (NW) respectively: 1) intact, 2) ovariectomized (OVX+V), 3) ovariectomized and estrogen treated (OVX+E), 4) ovariectomized and estrogen plus progesterone treated (OVX+E+P) groups. Hypothalami from experimental animals were dissected out and used for determination of .alpha.-adrenergic receptor binding characteristics and catecholamine contents. Norepinephrine(NE) content and B$_{max}$ of $\alpha_1$-adrenergic receptors in hypothalami were greater in intact SHR than in intact NW, but dopamine(DA) content was lower in SHR than in NW. Neither contents of NE and DA nor binding characteristics of $\alpha_1$-adrenergic receptors were different in OVX+V and OVX+E group from intact group of both SHR and NW. Kd and B$_{max}$ of $\alpha_1$-adrenergic receptors in OVX+E+P was lower than that in intact SHR but not in NW. DA content was lower in OVX+E+P than in intact group of SHR and NW. The result of the present study indicates that there is an abnormal responsiveness of hypothalamic catecholaminergic nervous system to ovarian steroid hormones in SHR which may be one of genetically-determined factors probably not responsible for the development of hypertension.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.177-177
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• 2002

• Proceedings of the Korean Nutrition Society Conference
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• 2002.05a
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• pp.100-100
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• 2002

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.219-231
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• 1995

Vasoactive intestinal polypeptide(VIP) and ${\beta}-adrenergic$ agonists have immunomodultory effects on the peripheral blood T-lymphocytes of rat through their own receptors. Both of them utilize the same signal transduction pathway. That is, the stimulatory guanine nucleotide binding protein(G protein) mediates the receptor-adenylyl cyclase coupling, producing intracellular increase of cyclic adenosine monophosphate(cAMP). In the previous experiment, propranolol, a ${\beta}-adrenergic$ receptor blocker, inhibited the VIP-induced protein phosphorylation in lymphocytes. However, propranolol could not block the effect induced by forskolin. Therefore, this study was designed to elucidate the mechanism of the inhibitory action of propranolol on the effects of VIP. Using peripheral blood lymphocytes of rats, the effect of propranolol on the receptor binding characteristics of VIP was observed. And the effects of propranolol were compared to the effects of timolol on the cAMP increase induced by isoproterenol, VIP or forskolin. The results obtained are as follows. 1) Receptor binding study showed no significant differences in the affinity or density of VIP receptor between the control and propranolol-pretreated groups. 2) VIP-induced increase of cAMP was inhibited by propranolol, but not by timolol. 3) Both propranolol and timolol suppressed the isoproterenol-induced cAMP increase. 4) Propranolol also inhibited the histamine-induced cAMP increase. 5) Propranolol did not inhibit the increase of cAMP stimulated by forskolin. 6) Lidocaine did not block the VIP-induced cAMP increase. These results show that the inhibitory mechanism of propranolol is not related to ${\beta}-adrenergic$ receptor or its membrane stabilizing effect, and it is suggested that propranolol can block the effects of VIP by inhibiting the intermediate step between the VIP receptor and adenylyl cyclase.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.71-78
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• 2004

Adrenergic receptors play a major role in thermogenesis and lipolysis in brown and visceral adipose tissues, and have been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of $\beta$2-adrenergic receptor ($\beta$2AR) and $\beta$3-adrenergic receptor ($\beta$3AR) genotypes on hyperglycemia and obesity in the Korean population. A representative sample consisting of 530 Korean men and women were measured for height, weight, BMI, WHR, obesity index and body composition. The genotypes of $\beta$2AR polymorphism in codon 27 and $\beta$3AR polymorphism in codon 64 were analyzed by the PCR RFLP method. Serum concentrations of fasting glucose, total cholesterol, HDL cholesterol and triglyceride were determined. The frequencies of $\beta$2AR and $\beta$3AR genotype were: both wild type, 62.5% ; only $\beta$2AR variant type, 12.8% ; only $\beta$3AR variant type, 18.8% ; and both variant type, 5.8% ; the frequency of E and R alleles were 0.098 and 0.137, respectively. Among the physiological parameters, fasting glucose level was significantly higher in subjects with both variant type compared with the three other types (p <0.05), Subjects with both variant type had 12%, 12% and 9.3% increases in serum glucose levels compared with wild type, only $\beta$2AR variant type, and only $\beta$3AR variant type, respectively. When logistic regression analysis was conducted to estimate the risk for hyperglycemia, the subjects were selected for fasting blood glucose concentrations of more than 6.105 m㏖/L (110 mg/dL), and the odds ratios were 1.215 (p=0.636) for only $\beta$2AR variant type,1.659 (p=0.089) for only $\beta$3AR variant type, and 3.078 (p=0.011) for both variant type. These results suggest that the interaction of $\beta$2AR and $\beta$3AR variant genotypes has a strong association with increased glucose levels, and might be a significant risk factor for hyperglycemia among Korean subjects.

• Analytical Science and Technology
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• v.17 no.1
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• pp.53-59
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• 2004

Up to now, methods for the detection of genetic alterations as single strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) have been used. It is too labor-intensive and expensive to serve for routine analysis. Moreover, lower in its sensitivity and specificity being also strongly dependent on the experience of the investigater. To improve these problems, we analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed phase chromatography (IP-RPC). We extracted genomic DNA from 80 asthma patients and then amplified DNA using PCR and analysed PCR product by SSCP and DHPLC. As a result, we analysed mutation frequency is 19 (23.75%) on SSCP and 25 (31.25%) on DHPLC in ${\beta}_2$-adrenergic receptor gene. We conclude that DHPLC is a fast and simple screening method rather than SSCP analysis.