• 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.

• Korean Journal of Veterinary Research
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• v.24 no.1
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• pp.17-23
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• 1984

To validate the physiological properties of the histamine receptors of ileal smooth muscle in dog, the effects of adrenergic-, cholineric-, and H-receptor antagonists on the responses of ileal smooth muscle strips to histamine were investigated. The results were summarized as follows; 1. Histamine caused the contraction of ileal smooth muscle and the contractile responses were increased between the concentration of histamine $10^{-7}M$ and $10^{-5}M$ with dose-dependent manner in dog. 2. The shorter the treatment interval of histamine, the lower the contractile activity until the treatment interval extended to 40 minutes. 3. The contractile response induced by histamine was completely blocked by the pre treatment with a $H_1$-receptor blocker, chlorpheniramine and not by the pretreatment with a $H_2$-receptor blockers cimetidine. 4. The contractile response induced by histamine was not blocked by the pretreatment with a cholinergic receptor blocker, atropine. 5. The contractile response induced by histamine was not blocked by the pretreatment with an ${\alpha}$-adrenergic receptor blocker, phenoxybenzamine, or a ${\beta}$-adrenergic receptor blocker, propranolol. From these results, it was suggested that the contraction induced by histamine was elicited through $H_1$-receptor on the ileal smooth muscle in dog.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.472-477
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• 1999

To elucidate the action of the cholinergic and adrenergic nerve on isolated gastric fundus smooth muscle of rabbit, the effects of electrical transmural stimulation were investigated in the presence of atropine, cholinergic receptor blocker; phentolamine, nonselective ${\alpha}$-adrenergic receptor blocker; propranolol, nonselective ${\beta}$-adrenergic receptor blocker and L-arginine from the isometric contraction of physiological recording system. 1. The contractile response induced by electrical transmural stimulation was increased as the frequency(1~32Hz)-dependent manner on the isolated gastric fundus smooth muscle. 2. The contractile response induced by electrical transmural stimulation was markedly inhibited by the pretreatment of atropine($1{\mu}M$). 3. The contractile response induecd by electrical transmutal stimulation was inhibited by the pretreatment of phentolamine($1{\mu}M$). 4. The relaxative response induced by electrical transmural stimulation on presence of atropine ($1{\mu}M$) was inhibited by the pretreatment of propranolol($1{\mu}M$). 5. The relaxative responses on precontraction induced by histamine($10{\mu}M$) with guanethidine ($50{\mu}M$) and atropine($1{\mu}M$) by electrical transmural stimulation were increased by L-arginine (1mM). These findings suggest that it was the excitatory action of cholinergic and ${\alpha}$-adrenergic nerve, and the inhibitory action of ${\beta}$-adrenergic nerve and nonadrenergic noncholinergic nerve on the isolated gastric fundus smooth muscle of rabbit.

• The Korean Journal of Pharmacology
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• v.16 no.1 s.26
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• pp.9-14
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• 1980

To evaluate the adrenergic receptors for glycogenolytic responses to catecholamine, the blood glucose level, liver glycogen content and muscle glycogen level in rats were studied with treatment of epinephrine, norepinephrine and isoproterenol. In addition, to study the possibility of interconversion of adrenergic receptors, the effects of catecholamines in feeding animal were compared with those in fasting animal. The results are summarized as follow; 1) Epinephrine and norepinephine showed dose dependent increase of blood glucose level but the effect of isproterenol was not significant. 2) The prandial states of animal did not influence on effects of catecholamines on blood glucose level. 3) Liver glycogen contents were lowered by epinephrine or by norepinephrins but effect of isoproterenol was not significant. 4) Glycogen content of skeletal muscle was significantly lowered by isoproterenol and. epinephrine shifted the dose-response curve to right, but the effect of norepinephrine was not significant. 5) The effects of epinephrine and norepinephrine on blood glucose were significantly blocked by ergotamine but not by propranolol. These results indicate that the glycogenolytic response to adrenergic agents in rat is mediated by an alpha-receptor in liver and by a beta-receptor in skeletal muscle.

• 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.

• YAKHAK HOEJI
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• v.35 no.4
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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.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.49-59
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• 1977

Adrenergic receptors are now classified into alpha type and beta type These adrenergic receptors are distributed in various tissue in different patterns. Therefore, the adrenergic response of a certain tissue may be different from those of the other tissues, and such differences may exist among various species of animals. In this paper, the authors attempt to reevaluate the effect of epinephrine on the isolated atria, aortic strips, and vas deferenses of rabbits preincubated with alpha receptor blockades (ergotamine and dibenamine) and beta receptor blockades (propranolol and dichloroisoproterenol) in Locke-Ringer bathing medium. The results obtained were summarized as follows; 1) The dose dependent responses of isolated atria to epinephrine were significantly inhibited by propranolol and dichloroisoproterenol, and slightly inhibited by dibenamine, but not affected by ergotamine. 2) The dose dependent responses of excised aortic strips to epinephrine were significantly inhibited by ergotamine and dibenamine, but the responses were slightly potentiated by propranolol, and significantly by dichloroisoproterenol. 3) The dose dependent responses of isolated vas deferenses to epinephrine were significantly inhibited by ergotamine and dibenamine, but slightly potentiated by propranolol and dichloroisoproterenol.

• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.28-28
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• 1997

Stimulation of $\alpha$$_1$-adrenergic receptor ($\alpha$$_1$-AR) by phenylephrine produced a decrease in intracellular N $a^{＋}$ activity ( $a_{Na}$ $^{i}$ ) in multicellular preparations of cardiac tissues. The role of protein kinase C (PKC) in $\alpha$$_1$-adrenergic regulation of $a_{Na}$ $^{i}$ was studied in single ventricular myocyte isolated from guinea pig hearts. $a_{Na}$ $^{i}$ and membrane potential were measured with N $a^{+}$ indicator, sodium-binding benzofuran isophthalate tetraacetoxy methyl ester (SBFI/AM) and microelectrodes respectively when ventricular myocyte was stimulated at 0.3 Hz.(omitted)d)

• The Korean Journal of Pharmacology
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• v.22 no.1 s.38
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• pp.24-33
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• 1986

To ascertain the existence of various adrenoceptors involved in active transport of sodium in the frog skin and to delineate their physiological roles, the influence of various adrenergic agonists and antagonists on the potential difference (PD), short-circuit current (SCC) and total skin conductance (TSC) of the isolated frog skin of Rana nigromaculata were investigated. PD and SCC were determined with Ussing's technique. Drugs were administered to the serosal side of the skin. Experimental results were summarized as follows: 1. The responses to norepinephrine (NE, $6{\times}10^{-8}-6{\times}10^{-5})M$), phenylephrine (PE, $5{\times}10^{-6}-5{\times}10^{-4}M$) and epinephrine (Epi, $5.5{\times}10^{-7}-5.5{\times}10^{-5}M$) were characterized by marked elevation of PD & SCC in dose-related fashion, but the maximal effect attained by Epi was less than those of NE and PE. 2. These increments of PD & SCC were significantly inhibited by prazosin $(2{\times}10^{-6}M)$, a speciflc ${\alpha}_1$-adrenoceptor blocker. The stimulatory effect on PD & SCC were completely abolished by phenoxybenzamine (PBZ, $3.3{\times}10^{-5}M$), an irreversible ${\alpha}$-adrenoceptor blocking agent. Furthermore, with a larger doses of Epi produced marked decline of PD & SCC after the PBZ pretreatment. 3. Isoproterenol (ISP), a ${\beta}$-adrenoceptor agonist, in concentrations ranging from $5{\times}10^{-7}$ to $5{\times}10^{-6}M$ produced dose-related decrease in PD & SCC, which could be abolished by pretreatment with propranolol $(4{\times}10^{-6}M)$, a specific ${\beta}$-adrenoceptor blocker. It was further noted that the effects of Epi on PD & SCC were markedly potentiated by Propranolol pretreatment. 4. Clonidine as well as guanabenz produced increases in PD & SCC and these effects were inhibited more specifically by prazosin pretreatment than by yohimbine. These results indicated that there exist in the frog skin two distinctive types of adrenoceptors, ${\alpha}$ and ${\beta}$, which roughly corresponds to those in mammals, and that the ${\alpha}$ type of adrenoceptors mediate the stimulation of PD & SCC, whereas ${\beta}$-adrenoceptors mediate the inhibition. However, based on evidence at hand, no conclusion could be drawn on the subtype of ${\alpha}$-adrenoceptors which is involved in the stimulation of sodium transport in the frog skin.

• The Korean Journal of Pharmacology
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• v.13 no.1 s.21
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• pp.13-21
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• 1977

The author confirmed the development of the smooth muscle in the oviduct proprius and anterior mesosalpinx in the leghorn, and observed that there was a variation between the action of norepinephrine on albumin-secreting portion of productive oviduct and that of non-productive one, and that $PGE_1$ might play a significant role on the activation of adrenergic ${\alpha}$-receptor in the non-productive oviduct. 1. There were many bundles of smooth muscles with irregular directions, which were identified in the both oviduct proprius and anterior mesosalpinx by Mallory aniline-blue orange G stain. 2. In vitro experiments, the anterior mesosalpinx was always relaxed by norepinephrine. While the albumin-secreting portion of non-productive period of oviduct was relaxed, but that of the productive one contracted by norepinephrine. Both the anterior mesosalpinx and oviduct proprius of chick responsed with relaxation to norepinephrine as shown in the non-productive hen. In vivo experiments, norepinephrine injected through the jugular vein increased the intraoviductal pressure in the productive oviduct, but decreased that in the non-productive one. 3. By treatment with $PGE_1$, in vitro, the relaxation induced not only by norepinephrine, but by periarterial electrical stimulation was converted into contraction, and in the presence of phentolamine, this conversion by $PGE_1$ was not shown. 4. The intra-oviductal pressure of the productive hen treated with indomethacin for 4 days was decreased by norepinephrine, but the increase in pressure by $PGE_1$ or $PGE_{2{\alpha}}$ was supersensitized when these drugs were administered through jugular vein. However, in vivo, the relaxation by norepinephrine was not converted into the stimulation after $PGE_1$ treatment. It might be summarized that the regulation of intra-oviductal pressure was dependent on the summation of the movement of both oviduct and mesosalpinx and intramurally produced prostaglandins contributes to the inherent tone of the prcductive oviduct by activating adrenergic ${\alpha}$-receptor.