• Journal of Convergence Korean Medicine
• /
• v.5 no.1
• /
• pp.25-44
• /
• 2023

Objectives: Gaming disorder has been viewed as a disease in the DSM-5 and ICD-11. Its essential symptoms are loss of control over gaming, gaming becoming a markedly prioritized activity over other activities of daily living, and continued and excessive use of gaming despite negative problems occurring. Methods: Children and adolescents are especially vulnerable to gaming disorder because the striatal pathways related to reward develop earlier than the control regions of the prefrontal cortex. It is also associated with decreased dopamine D2 receptors. Addiction is related to 'want' and is explained by incentive-sensitization. In addition, allostasis, in which homeostasis is continuously achieved at a new target value, is also related to gaming disorder. In addition, personality causes, unchangeable factors, and external factors can influence on the onset of gaming disorder. Results: Prevention is the best solution for gaming disorder, and the role of parents is important. For gaming disorder, bupropion is used, cognitive-behavioral therapy and family-based therapy are also beneficial. Herbal medicine treatment such as Antler velvet and ginseng can be effective. Electroacupuncture and acupuncture using PC6, SP6, and LR3 has a correlation with relieving Internet craving. Ear-acupuncture was also effective in treating addiction. Conclusion: Psychologically, 'want' is an intense longing for reward and motivation, and is related to addiction. This 'want' may rather be related to avoidance, and game addiction in children and adolescents may be due to wanting to escape from academic stress or avoidance of comparison. Therefore, the importance of 'like', which gives pleasure in itself, increases. It can also be explained with Sasang Constitutional Medicine.

• Advances in Traditional Medicine
• /
• v.3 no.2
• /
• pp.100-105
• /
• 2003

Systematic analysis of caffeine from the commercial samples of Indian tea leaves was performed by a routine method and the content of caffeine was found to be 19.0-37.4 mg/100 g leaves. The caffeine contents from coffee seeds and chicory from Indian origin were analyzed and found to be 0.6540-1.4920 g/100 g seeds. Caffeine contents of roasted Indian chicory roots were lower than either those of Indian tea leaves or Indian coffee seeds. The multidrug resistance (MDR) reversing effects were tested on a mouse leukemia cell line of L-5178 cells by methanol extracts [M1-M15] of Indian tea leaves and coffee seeds, comparing to a control of $({\pm})-verapamil$. The effects were measured by fluorescence ratio between treated and untreated group cells. Among fifteen methanol extracts, a Gemini tea [M6] (fluorescence activity ratio 5.26) had the most potent effect for L-5178 cells. The extract M6 was 0.63-fold of $({\pm})-verapamil$. We suggest that one of mechanisms of reversal by M6 might have strong affinity to dopamine $D_1$ and D_2$ receptors. Further studies with many more tumor and normal cell lines are necessary to confirm the MDR reversal specificity of coffee methanol extracts.

• Korean Journal of Veterinary Research
• /
• v.39 no.3
• /
• pp.463-471
• /
• 1999

Magnesium($Mg^{2+}$) is one of the most abundant intracellular divalent cation. Although recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in $Mg^{2+}$ homeostasis, the regulation of $Mg^{2+}$ by dopaminergic receptor stimulation is not yet known. In this work, we used dopaminergic agents to identify which type(s) of receptors were involved in the mobilization of $Mg^{2+}$ by dopaminergic receptor stimulation in the perfused rat hearts, isolated myocytes and circulating blood. The $Mg^{2+}$ content was measured by atomic absorbance spectrophotometry. Dopamine(DA), apomorphine(APO) and pergolide stimulated $Mg^{2+}$ efflux in the perfused rat hearts and these effects were inhibited by haloperidol or fluphenazine, nonselective dopaminergic antagonists. SKF38393, a selective doparminergic agonist, increased $Mg^{2+}$ efflux from the perfused hearts in dose dependant manners and SKF38393-induced $Mg^{2+}$ efflux was blocked by haloperidol. However, dopaminergic agonists-induced $Mg^{2+}$ efflux was potentiated in the presence of sulpiride or eticlopride, $D_2$-selective antagonist, from the perfused hearts. This increase of $Mg^{2+}$ efflux was blocked by haloperidol or imipramine. DA or pergolide increased in circulating $Mg^{2+}$ from blood. By contrast, PPHT stimulated $Mg^{2+}$ influx(a decrease in efflux) from the perfused hearts and circulating blood. PPHT-induced $Mg^{2+}$ influx was blocked by fluphenazine in the perfused hearts. DA-stimulated $Mg^{2+}$ efflux was inhibited by dopaminergic antagoinst in the isolated myocytes. In conclusion, the flux of $Mg^{2+}$ is modulated by DA receptor activation in the rat hearts. The efflux of $Mg^{2+}$ can be increased by $D_1$-receptor stimulation and decreased by $D_2$-receptor stimulation, respectively.

• Biomolecules & Therapeutics
• /
• v.23 no.3
• /
• pp.218-224
• /
• 2015

Endocannabinoids can affect multiple cellular targets, such as cannabinoid (CB) receptors, transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and peroxisome proliferator-activated receptor ${\gamma}$($PPAR{\gamma}$). The stimuli to induce adipocyte differentiation in hBM-MSCs increase the gene transcription of the $CB_1$ receptor, TRPV1 and $PPAR{\gamma}$. In this study, the effects of three endocannabinoids, N-arachidonoyl ethanolamine (AEA), N-arachidonoyl dopamine (NADA) and 2-arachidonoyl glycerol (2-AG), on adipogenesis in hBM-MSCs were evaluated. The adipocyte differentiation was promoted by AEA whereas inhibited by NADA. No change was observed by the treatment of non-cytotoxic concentrations of 2-AG. The difference between AEA and NADA in the regulation of adipogenesis is associated with their effects on $PPAR{\gamma}$ transactivation. AEA can directly activate $PPAR{\gamma}$. The effect of AEA on $PPAR{\gamma}$ in hBM-MSCs may prevail over that on the $CB_1$ receptor mediated signal transduction, giving rise to the AEA-induced promotion of adipogenesis. In contrast, NADA had no effect on the $PPAR{\gamma}$ activity in the $PPAR{\gamma}$ transactivation assay. The inhibitory effect of NADA on adipogenesis in hBM-MSCs was reversed not by capsazepine, a TRPV1 antagonist, but by rimonabant, a $CB_1$ antagonist/inverse agonist. Rimonabant by itself promoted adipogenesis in hBM-MSCs, which may be interpreted as the result of the inverse agonism of the $CB_1$ receptor. This result suggests that the constantly active $CB_1$ receptor may contribute to suppress the adipocyte differentiation of hBM-MSCs. Therefore, the selective $CB_1$ agonists that are unable to affect cellular $PPAR{\gamma}$ activity inhibit adipogenesis in hBM-MSCs.

• The Korean Journal of Physiology and Pharmacology
• /
• v.24 no.6
• /
• pp.545-553
• /
• 2020

Aripiprazole is a quinolinone derivative approved as an atypical antipsychotic drug for the treatment of schizophrenia and bipolar disorder. It acts as with partial agonist activities at the dopamine D2 receptors. Although it is known to be relatively safe for patients with cardiac ailments, less is known about the effect of aripiprazole on voltage-gated ion channels such as transient A-type K⁺ channels, which are important for the repolarization of cardiac and neuronal action potentials. Here, we investigated the effects of aripiprazole on Kv1.4 currents expressed in HEK293 cells using a whole-cell patch-clamp technique. Aripiprazole blocked Kv1.4 channels in a concentration-dependent manner with an IC₅₀ value of 4.4 μM and a Hill coefficient of 2.5. Aripiprazole also accelerated the activation (time-to-peak) and inactivation kinetics. Aripiprazole induced a voltage-dependent (δ = 0.17) inhibition, which was use-dependent with successive pulses on Kv1.4 currents without altering the time course of recovery from inactivation. Dehydroaripiprazole, an active metabolite of aripiprazole, inhibited Kv1.4 with an IC₅₀ value of 6.3 μM (p < 0.05 compared with aripiprazole) with a Hill coefficient of 2.0. Furthermore, aripiprazole inhibited Kv4.3 currents to a similar extent in a concentration-dependent manner with an IC₅₀ value of 4.9 μM and a Hill coefficient of 2.3. Thus, our results indicate that aripiprazole blocked Kv1.4 by preferentially binding to the open state of the channels.

• Korean Journal of Biological Psychiatry
• /
• v.2 no.1
• /
• pp.63-69
• /
• 1995

The effects of chronic treatment with haloperidol and sulpiride on the binding capacities of dopamine(DA) receptor were examined in rat striatum and olfactory tubercle. Additionally, the stereotypy scores were assessed after apomorphine administration. Rats were treated with haloperidol(0.5mg/kg/day) or sulpiride(40mg/kg/day) for four weeks. Apomorphine(0.5mg/kg) was injected after three-day washout from neuroleptics, and stereotypy scores were assessed. Haloperidol group showed high scores of stereotyped behavior in comparison with control and sulpiride groups. With control group, sulpiride group displayed similar stereotyped behaviors. Saturation analysis of the binding of [$^3H$]spiperone to striatal membranes showed that the Bmax of haloperidol and sulpiride groups increased significantly in comparison with that of control group. The $K_D$ decreased significantly after sulpiride treatment in striatum. Although sulpiride produces the same proliferation of DA receptor, the low stereotypy scores of sulpiride group indirectly suggest that sulpiride acts differently from haloperidol in brain DA system. The Bmax increased remarkably following both treatment with haloperidol and sulpiride in olfactory tubercle. Also, the increase in $K_D$ was significant after treatment with haloperidol and sulpiride in olfactory tubercle. Moreover, the $K_D$ of control group in olfactory tubercle was more than twice the $K_D$ of control group in striatum. The $K_D$ was 86.2 in striatum and 37.5 pM in olfactory tubercle. The present finding indicates that sulpiride also induces the proliferation of DA receptor in olfactory tubercle and may interact with some DA receptor subtype with high affinity profile. The different affinities of the control groups of striatum and olfactory tubercle suggest that striatal DA receptor subtypes labeled by [$^3H$]spiperone could differ from those of olfactory tubercle.

• The Korean Journal of Pharmacology
• /
• v.30 no.1
• /
• pp.87-100
• /
• 1994

It has been known for some time that dopamine-containing cells are existed in sympathetic ganglia, i.e., small, intensely fluorescent cells. However, its role and mechanism of action as a peripheral neurotransmitter are poorly understood so far. In the present study, an attempt was made to examine the effect of apomorphine, which is known to be a selective agonist of dopaminergic $D_2$. receptor on secretion of catecholamines (CA) from the isolated perfused rat adrenal gland. The perfusion of a low concentration of 10uM apomorphine into an adrenal vein for 20 min produced significant reduction in CA secretion induced by 5.32 mM ACh, 56 mM KCl, 100 uM DMPP and 100 uM McN-A-343. Increasing apomorphine concentration to 30 uM led to more markedly decreased CA secretion as compared to the case of 10 uM apomorphine and also did inhibit clearly CA release by $10^{-5}M$ Bay-K-8644. Furthermore, in adrenal glands preloaded with a higher dose of 100 uM apomorphine, CA releases evoked by ACh, excess $K^+$, DMPP and McN-A-343 were almost abolished by the drug. The perfusion of $3.3{\pm}10^{-5}M$ metoclopramide, which is well-known as a selective dopaminergic $D_2$ antagonist, produced significantly inhibitory effect of CA release by ACh, DMPP and McN-A-343 but did not affect that by excess $K^+$. However, preloading of 30uM apomorphine in the presence of metoclopramide did not modify the CA secretory effect of excess $K+$ and DMPP. These experimental results demonstrate that apomorphine causes dose-dependent inhibition of CA secretion by cholinergic receptor stimulation and also by membrane depolarization from the isolated perfused rat adrenal gland, suggesting that these effects appear to be exerted by inhibiting influx of extracellular calcium into the rat adrenal medullary chromaffin cells through activation of inhibitory dopaminergic receptors.