• International Journal of Oral Biology
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• v.36 no.4
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• pp.173-178
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• 2011

Tumor necrosis factor alpha ($TNF{\alpha}$) is a multifunctional cytokine that is elevated in inflammatory diseases such as atherosclerosis, diabetes and rheumatoid arthritis. Recent evidence has suggested that ${\beta}2$ adrenergic receptor (${\beta}2AR$) activation in osteoblasts suppresses osteogenic activity. In the present study, we explored whether $TNF{\alpha}$ modulates ${\beta}AR$ expression in osteoblastic cells and whether this regulation is associated with the inhibition of osteoblast differentiation by $TNF{\alpha}$. In the experiments, we used C2C12 cells, MC3T3-E1 cells and primary cultured mouse bone marrow stromal cells. Among the three subtypes of ${\beta}AR$, ${\beta}2$ and ${\beta}3AR$ were found in our analysis to be upregulated by $TNF{\alpha}$. Moreover, isoproterenol-induced cAMP production was observed to be significantly enhanced in $TNF{\alpha}$-primed C2C12 cells, indicating that $TNF{\alpha}$ enhances ${\beta}2AR$ signaling in osteoblasts. $TNF{\alpha}$ was further found in C2C12 cells to suppress bone morphogenetic protein 2-induced alkaline phosphatase (ALP) activity and the expression of osteogenic marker genes including Runx2, ALP and osteocalcin. Propranolol, a ${\beta}2AR$ antagonist, attenuated this $TNF{\alpha}$ suppression of osteogenic differentiation. $TNF{\alpha}$ increased the expression of receptor activator of NF-${\kappa}B$ ligand (RANKL), an essential osteoclastogenic factor, in C2C12 cells which was again blocked by propranolol. In summary, our data show that $TNF{\alpha}$ increases ${\beta}2AR$ expression in osteoblasts and that a blockade of ${\beta}2AR$ attenuates the suppression of osteogenic differentiation and stimulation of RANKL expression by $TNF{\alpha}$. These findings imply that a crosstalk between $TNF{\alpha}$ and ${\beta}2AR$ signaling pathways might occur in osteoblasts to modulate their function.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.4
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• pp.271-279
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• 2019

The lamina II, also called the substantia gelatinosa (SG), of the trigeminal subnucleus caudalis (Vc), is thought to play an essential role in the control of orofacial nociception. Glycine and serotonin (5-hydroxytryptamine, 5-HT) are the important neurotransmitters that have the individual parts on the modulation of nociceptive transmission. However, the electrophysiological effects of 5-HT on the glycine receptors on SG neurons of the Vc have not been well studied yet. For this reason, we applied the whole-cell patch clamp technique to explore the interaction of intracellular signal transduction between 5-HT and the glycine receptors on SG neurons of the Vc in mice. In nine of 13 neurons tested (69.2%), pretreatment with 5-HT potentiated glycine-induced current ($I_{Gly}$). Firstly, we examined with a $5-HT_1$ receptor agonist (8-OH-DPAT, $5-HT_{1/7}$ agonist, co-applied with SB-269970, $5-HT_7$ antagonist) and antagonist (WAY-100635), but $5-HT_1$ receptor agonist did not increase $I_{Gly}$ and in the presence of $5-HT_1$ antagonist, the potentiation of 5-HT on $I_{Gly}$ still happened. However, an agonist (${\alpha}$-methyl-5-HT) and antagonist (ketanserin) of the $5-HT_2$ receptor mimicked and inhibited the enhancing effect of 5-HT on $I_{Gly}$ in the SG neurons, respectively. We also verified the role of the $5-HT_7$ receptor by using a $5-HT_7$ antagonist (SB-269970) but it also did not block the enhancement of 5-HT on $I_{Gly}$. Our study demonstrated that 5-HT facilitated $I_{Gly}$ in the SG neurons of the Vc through the $5-HT_2$ receptor. The interaction between 5-HT and glycine appears to have a significant role in modulating the transmission of the nociceptive pathway.

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.15-22
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• 2009

Because it is known that bivalve hearts contain various modulatory systems activated by neuroendocrine substances, it was examined whether different classes of endogenous and synthetic drugs of neuroendocrinological importance can influence cardiac functions of the Pacific oyster Crassostrea gigas. Cholinergically active agents acetylcholine and carbachol increased heart rates while diminishing cardiac contractility. Adrenergically active substances norepinephrine (NE) and epinephrine (Epi) also induced heart rate increase and contractility decrease. An $\alpha_1$-adrenergic receptor-selective agonist phenyephrine (PE) failed to modulate either parameter. The Epi-induced heart rate increase and contractile depression were both blocked significantly by non-selective $\beta_1/\beta_2$-adrenergic antagonist propranolol. A $\beta_1$-selective antagonist atenolol prevented Epi-induced heart rate decrease but not the contractile depression, suggesting possible $\beta_2$ receptors for Epi-induced contractile depression. The three autacoids examined exerted discrete responses: histamine increased heart rate and depressed contraction; $\gamma$-amino-butyric acid increased both parameters; serotonin failed to change either parameter. The 5 piscine anesthetic agents examined, MS-222, benzocaine, quinaldine, urethane, pantocaine and pentobarbital, all failed to influence the cardiac function of oysters. Collectively, activities of neuroendocrinologically acting agents in mammals showed unexpected and distinct activities from those in mammalian cardiovascular systems. These results obtained from substances of different physiological functions can serve as a basis for understanding neuroendocrine control of the heart function in Pacific oyster.

• Korean Journal of Acupuncture
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• v.25 no.3
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• pp.81-96
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• 2008

Objectives : The purpose of the present study is to determine the effective analgesic parameters of manual acupuncture (MA) and/or electroacupuncture (EA), thus how MA & EA of specific acupoint works after acute ankle sprain in rats. Thus, one series of experiments was designed to analyze the analgesic effects of acupuncture in either the normal or sprained rat, by comparing the behavioral features before and after MA or EA at several acupoints. Methods : Ankle sprain was induced manually by hyper-extension of ligaments of the right ankle in rat. Either MA or EA was applied to the LI4, TE17, 足三里 and SI-6 acupoints at an intensity of 2 mA (1 ms pulse duration) with a frequency of 10 Hz for 30 minutes. Results : Behaviorally, manual acupuncture or electroacupuncture produced potent analgesic effects on acute ankle sprained animals as measured by weight bearing capacity of the affected limb. Furthermore, antinociceptive effect of EA was suppressed by alpha adrenoceptor antagonist phentolamine (5 mg/kg, i.p.) but not by opioid antagonist naltrexone (10 mg/kg, i.p.). Conclusions : It is suggested that acupuncture-induced antinociception may involve the descending inhibition of ${\alpha}2$-adrenoceptor.

• Journal of Veterinary Clinics
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• v.7 no.2
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• pp.501-509
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• 1990

This study was designed to examine effects of $\alpha$$_2$-Adrenergic Antagonists on blood chemical values in xylazine-sedated dogs. Twenty-four crossbred dogs of both sexes were intramusculary injected with a standard dosage of xylazine(2.2mg/kg of body weight). Righting reflex was uniformly lost and considered to be the point of maximum sedation. When the dogs were maximally sedated, tested groups were in-travenously injected with yohimbine 0.125mg/kg, 4-aminopyridine(4-AP) 0.3mg/kg, and a combination of yohimbine with 4-AP. Control group was intravenously 1 $m\ell$ of physiological saline solution. Total protein(T.P), albumin, glucose, aspartate aminotransferase(AST), alanine aminotrnasferase(ALT), blood urea nitrogen(BUN) were analyzed in the conditions of 0-, 30-, 60- and 120-minute after the administration of drugs. The results obtained in the study were as follows. 1. Changes of T.P, albumin, AST, ALT and BUN values in the control group were not significant during or after xylazine administration for at least 120minutes. 2. No changes of T.P, albumin, AST, ALT and BUN values in the tested groups were observed during or after $\alpha$$_2$-Adrenergic Antagonists treatment. 3. Serum glucose values of control group were getting remarkably increased after xylazine injection. 4. The xylasine-induced hyperglycemia was reversed in the dogs administrated with $\alpha$$_2$-Adrenergic Antagonists. Therefore, the results of the study show that the combined treatment with antagonists may be useful for accidental overdoses of xylazine and rapid reversal of animals sedated with xylazine.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.5
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• pp.577-584
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• 2018

Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2-10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine $A_1$ receptor antagonist), udenafil (PDE5 inhibitor), prazosin (${\alpha}_1$-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in $PLC/IP_3$-mediated intracellular $Ca^{2+}$ release and PDE5 activity.

• Korean Journal of Acupuncture
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• v.23 no.2
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• pp.113-123
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• 2006

Objectives: Pharmacopuncture which is a combination of acupuncture and herbal medicine helps to prevent and treat the diseases and symptoms including various pains. However, little was known about the therapeutic effects and its mechanisms on acute pain, although pharmacopuncture has been used frequently in acupuncture clinics. Acupuncture is known for producing analgesia for persistent ankle sprain pain in human. Furthermore, it also produces analgesia in a rat model of ankle sprain pain. Methods: To illuminate the underlying mechanisms of capsaicin pharmacopuncture-induced analgesia, weight bearing force (WBF) was observed on the acute ankle sprained rat model. Ankle sprain was induced in the rat by manually hyper-extending ligaments of the right ankle. Capsaicin pharmacopuncture was applied to SI6 (Yanglo) on the left forelimb (contralateral to the sprained ankle). Results: In behavioral test, capsaicin pharmacopuncture produced marked analgesic effects on acute ankle sprained animals as measured by WBF of the affected limb similar to manual acupuncture. Capsaicin pharmacopuncture was also suppressed by serotonin (5-HT) receptor antagonist methysergide (2 mg/kg, Lp.), but not by opioids receptor antagonist naltrexone (10 mg/kg, Lp.) and alpha adrenoceptor antagonist phentolamine (5 mg/kg, Lp.). Conclusion: The data suggest that capsaicin pharmacopuncture-induced analgesia is accomplished by activating the descending serotonergic inhibitory systems.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.53-73
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• 2002

It has been reported that degranulation of mast cells in rats, rabbits and dog was observed after dosing xylazine hydrochloride(Xh) which has been widely used as sedative, analgesic and muscular relaxant. Therefore, this experiment was conducted to examine the relations between Xh and histamine release and to identify the action of ${\alpha}$-adrenoceptors which exists on the suface of mast cells. 1. The content of histamine within serum was measured with HPLC by performing the O-phthalaldehyde(OPA) fluorescent derivation. The pretreatment method had a little modification from the conventional method. The pretreament was carried out in the following method. 0.2$m\ell$ of serum and 1$m\ell$ of butanol were added to mixed together and then the liquid was centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 3 minutes. 0.4$m\ell$ of 0.1N HCl and 1.6$m\ell$ of heptane were added to 0.8$m\ell$ of supernatant taken from the liquid, and they were mixed together. This mixture was also centrifugally separated at 4$^{\circ}C$ and 2,000 rpm for 5 minutes. The supernatant was thrown away and the OPA fluorescent derivation was carried out with 0.2$m\ell$ of the lower liquid then, 5 minutes after mixing 400${\mu}\ell$ of 0.1N HCl, 120${\mu}\ell$ of 1N NaOH and 40${\mu}\ell$ of 0.1% OPA in the 0.2$m\ell$ of the lower liquid,120${\mu}\ell$ of 3.57N H$_3$PO$_4$ was added to the mixed liquid, and the liquid, was mixed again and syringe-filtered. Then, the measurement was done with HPLC in the 30 : 70(ν/ν) ratio of 0.004M KH$_2$PO$_4$: CH$_3$CN, flow rate of 1.0$m\ell$/min., and a wavelength of λex= 350nm and λem=444nm at the column temperature of 27$^{\circ}C$, using the fluorescence detector. 2. The content of histamine in each laboratory animal appeared to be higher in such an order as rabbit, rat, guinea pig, dog, Korean indigenous goat, swine, Korean indigenous cattle, Holstein, and mouse, of which the individual mean values${\pm}$standard deviation were 2.0668 ${\pm}$ 0.6049. 0.4999 ${\pm}$ 0.2278, 0.4241 ${\pm}$ 0.1974, 0.1054 ${\pm}$ 0.0556, 0.1028 ${\pm}$ 0.0276, 0.0972 ${\pm}$ 0.0513, 0.0872 ${\pm}$ 0.0373, 0.0717 ${\pm}$ 0.0379, and 0.0706 ${\pm}$ 0.0366, respectively. 3. The content of histamine was measured at the moments of 15-, 30-, 60-, 120-minutes after inoamuscular injection of 20mg/100kg Xh into two to 4 years old Holstein weighing 600∼700kg. The result showed that there was a significant increase at the times of 30- and 90-minutes after injection(p<0.05). 4. Intramuscular injection of 3mg/10kg Xh was given to crossbred pug dogs weighing 2.5∼4.3kg. The content of histamine was measured at the times of 30-, 60-, 90- and 120-minutes after injection. The result revealed that there was a significant increase at the times of 60-and 90-minutes after injection(p<0.05). 5. Intramuscular injection of 10mg/$m\ell$∼25mg/$m\ell$ Xh in concentration of 0.1$m\ell$ was applied to Korean indigenous goat over 5 months old. Then, the content of histamine was measured at the times of 15-, 30-, 60- and 90-minutes after injection. A significant increase was shown at the times of 30- and 60-minutes after injection(p<0.05). 6. The content of histamine was measured at the moments of 30- and 60-minutes after intramuscular injection of 0.1-0.2$m\ell$ Xh (20mg/$m\ell$) into male rabbits weighting 2.5-4kg. A significant increase was found at the moment of 60 minutes after injection(p<0.001). 7. After administering Xh to the mast cell taken from the abdominal cavity of mouse, the content of histamine was measured. The result showed that the higher the concentration, the more significantly the content of histamine was increased(p<0.05). 8. Compound 48/80 was administered in concentration of 5$\mu\textrm{g}$/$m\ell$ and 10$\mu\textrm{g}$/$m\ell$ to the mast cell picked from the abdominal cavity of mouse. The result showed that there was a significant increase in the content of histamine in case of the concentration of 10$\mu\textrm{g}$/$m\ell$(p<0.05). It was found to be about 10,000 to 500,000 times stronger than the Xh. 9. After premedication of 1mg/kg of yohimbine hydrochloride as ${\alpha}$$_2$-adrenergic antagonist to rabbits, the Xh was administered to them. The result was that the value of histamine within serum was decreased significantly(p<0.001). 10. After premeditation of 1mg/kg of prazosin hydrochloride as ${\alpha}$$_1$-adrenergic antagonist to rabbits, the Xh was administered to them. It was found that the value of histamine within serum was decreased significantly(p<0.005). 11, Prazosin hydrochloride and yohimbine hydrochloride as ${\alpha}$$_1$-adrenergic antagonist, respectively, and ${\alpha}$$_2$-adrenergic antagonist were administerd. In this case, the value of histamine within serum was decreased significantly(p<0.0001). As the results, when the Xh is administered to various kinds of animals, the amount of histamine release within serum is increased. In view of the results so far achieved, it is concluded that Xh acted on both a$_1$-adrenoreceptor and ${\alpha}$$_2$-adrenoreceptor induces the degranulation of mast cell.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.165-174
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• 1999

We explore the question of whether adenosine 5'-triphosphate (ATP) acts as an excitatory neurotransmitter in guinea-pig gastric smooth muscle. In an organ bath system, isometric force of the circular smooth muscle of guinea-pig gastric antrum was measured in the presence of atropine and guanethidine. Under electrical field stimulation (EFS) at high frequencies (＞20 Hz), NO-mediated relaxation during EFS was followed by a strong contraction after the cessation of EFS (a 'rebound-contraction'). Exogenous ATP mimicked the rebound-contraction. A known $P_{2Y}-purinoceptor$ antagonist, reactive blue 2 (RB-2), blocked the rebound-contraction while selective desensitization of $P_{2Y}-purinoceptor$ with ${\alpha},{\beta}-MeATP$ did not affect it. ATP and 2-MeSATP induced smooth muscle contraction, which was effectively blocked by RB-2 and suramin, a nonselective $P_2-purinoceptor$ antagonist. Particularly, in the presence of RB-2, exogenous ATP and 2-MeSATP inhibited spontaneous phasic contractions, suggesting the existence of different populations of purinoceptors. Both the rebound-contraction and the agonist-induced contraction were not inhibited by indomethacin. The rank orders of agonists' potency were 2-MeSATP > ATP ${ge}$ UTP for contraction and ${\alpha},{\beta}-MeATP\;{\ge}\;{\beta},{\gamma}-MeATP$ for inhibition of the phasic contraction, that accord with the commonly accepted rank order of the classical $P_{2Y}-purinoceptor$ subtypes. Electrical activities of smooth muscles were only slightly influenced by ATP and 2-MeSATP, whereas ${\alpha},{\beta}-MeATP$ attenuated slow waves with membrane hyperpolarization. From the above results, it is suggested that ATP acts as an excitatory neurotransmitter, which mediates the rebound-contraction via $P_{2Y}-purinoceptor$ in guinea-pig gastric antrum.

• Korean Journal of Acupuncture
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• v.26 no.2
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• pp.75-89
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• 2009

Objectives: Warm needling combines simultaneously the effects of acupuncture and moxibustion. This study was to investigate whether warm needling could relieve acute knee arthritis induced by carrageenan in rats. Methods: To illuminate the underlying mechanisms of the warm needling-induced antinociception, weight bearing force (WBF) was observed on the acute knee arthritic rat model. Under general anesthesia, ST36, SP9, Hakjung extra point, LI4 were punctured and stimulated with 30 mg moxa ball combustion on top of the needle (${\emptyset}0.18{\times}8mm$). Results: In behavioral test, rats subsequently showed a reduced stepping force of the affected limb 3 hours after the induction of arthritis. Warm needling on the contralateral or ipsilateral ST36 failed to show antinociceptive effect on the acute knee arthritis. Warm needling on the contralateral SP9 or LI4 increased WBF values to normal level in the acute stage of the arthritis. Warm needling on the Hakjung extra-point resulted in the significant antinociceptive effects through acute stage. These effects of warm needling were suppressed by opioids receptor antagonist naltrexone (10 mg/kg, i.p.) and alpha adrenoceptor antagonist phentolamine (5 mg/kg, i.p.). Conclusion: The data suggest that warm needling-induced antinociception is differently mediated by acupoints and accomplished by activating the descending inhibitory systems including endogenous opioids and $\alpha$-adrenoceptors.