• Proceedings of the Korean Society of Applied Pharmacology
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• 2005.11a
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• pp.49-66
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• 2005

Panax ginseng has been useful for the treatment of diverse disease in oriental countries for thousands of years. In addition, a folk medicine prescribed by seven herbal drugs including Panax ginseng has been antinarcotics in the treatment of morphine-dependent patients. Many articles have been reported on these works. Therefore, we review the protective effects of Panax ginseng on the neurotoxicity induced by abuse drugs. Ginseng total saponins (GTS) extracted and isolated by Panax ginseng antagonized Morphine-induced analgesia, and inhibited the development of analgesic tolerance to and physical dependence on morphine. GTS inhibited morphine-6 dehydrogenase, which catalyzes production of mophinone from morphine, and increased hepatic glutathione level responsible to toxicity. Therefore, we hypothesized that these dual actions of ginseng can be associated with the detoxication of morphine. In addition, the inhibitory or facilitated effects of GTS on electrically evoked contraction in guinea pig ileum ($\mu$-receptors) and mouse vas deferens($\delta$-receptors) were not mediated through opioid receptors, suggesting non-opioid mechanisms. On the hand, antagonism of U-50,488H ($\kappa$-agonist)-induced antinociception is mediated by serotonergic mechanisms. GTS also inhibited hyperactivity, reverse tolerance (sensitization) and conditioned place preference-induced by psychostimulants such as methamphetamine, cocaine and morphine. On the other hand, GTS reduced the dopamine levels induced by methamphetamine. Moreover, GTS blocked the development of dopamine receptor activation, showing antidopaminergic effect. We suggest that GTS Prevent the methamphetamine-induced striatal dopaminergic neurotoxicity. In addition, Ginsenoside also attenuates morphine-induced cAMP signaling pathway. These results suggested that GTS might be useful for the therapy of the adverse actions of drugs with abuse liability.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.32-42
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• 2009

The purpose of the present study was to examine the effect of dihydrexidine, a full $D_1$ receptor agonist, on the secretion of catecholamines (CA) from the perfused model of the rat adrenal gland, and to establish its mechanism of action. Dihydrexidine (10-100 ${\mu}M$), perfused into an adrenal vein for 60 min, relatively produced dose- and time-dependent inhibition in the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Dihydrexidine itself did fail to affect basal CA output. Also, in adrenal glands loaded with dihydrexidine (30 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$), an activator of L-type $Ca^{2+}$ channels, cyclopiazonic acid (10 ${\mu}M$), an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, and veratridine, an activator of voltage-dependent $Na+$ channels (10 ${\mu}M$), were also markedly inhibited, respectively. However, in the simultaneous presence of dihydrexidine (30 ${\mu}M$) and R (+)-SCH23390 (a selective antagonist of $D_1$ receptor, 3 ${\mu}M$), the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory responses by dihydrexidinetreatment alone. In conclusion, these experimental results suggest that dihydrexidine significantly inhibits the CA secretion evoked by cholinergic stimulation (both nicotinic and muscarinic receptors) and membrane depolarization from the rat adrenal medulla. It seems that this inhibitory effect of dihydrexidine may be mediated by inhibiting influx of both $Ca^{2+}$ and $Na^+$ into the cytoplasm as well as by suppression of $Ca^{2+}$ release from cytoplasmic calcium store through activation of dopaminergic $D_1$ receptors located on the rat adrenomedullary chromaffin cells.

• Animal cells and systems
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• v.4 no.1
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• pp.71-76
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• 2000

The aim of this study was to investigate expression patterns of the prolactin (PRL) and c-fos genes by 17$\beta$-estradiol (17$\beta$-E) and stress in the mouse pituitary. In the pituitary, the levels of PRL mRNA were found high with some fluctuation at 30, 50, and 90 min whereas the levels of PRL mRNA were low at 120 min when ovariectomized female mice were injected with 17$\beta$-E or vehicle. PRL mRNA levels began to increase again at 4 h and remained high up to 24 h only in the 17$\beta$-E- treated mice. The overall changes in c-fos mRNA by 17$\beta$-E were very similar to those in PRL mRNA in the pituitary. Subsequent study revealed that these high initial levels of PRL and c-fos mRNAs were caused by stress during Injection, not by 17$\beta$-E, since vehicle injection alone into the ovariectomized mice could increase the levels of PRL and c-fos mRNAs. The stress-induced elevations of PRL and c-fos mRNAs were inhibited by bromocriptin, a dopamine agonist, suggesting that the dopaminergic system is involved in the action route of injection stress. In addition, the induced levels of c-fos mRNA by 17$\beta$-E and stress in the pituitary were very low compared with those in the uterus. The time course changes in c-fos mRNA level were different between the pituitary and uterus. Taken together, these data indicate that PRL and c-tos gene expression in the pituitary are regulated by 17$\beta$-E and stress in a parallel manner, supporting the notion that c-Fos plays a role in regulation of PRL gene expression.

• Proceedings of the Ginseng society Conference
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• 2005.11a
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• pp.41-63
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• 2005

Ginseng has been useful for the treatment of diverse disease in oriental countries for thousands of years. In addition, a folk medicine prescribed by seven herbal drugs including Panax ginseng has been antinarcotics in the treatment of morphine-dependent patients. Many articles have been reported on these works. Therefore, we review the protective effects of Panax ginseng on the neurotoxicity induced by abuse drugs. Ginseng total saponins (GTS) extracted and isolated by Panax ginseng antagonized morphine-induced analgesia, and inhibited the development of analgesic tolerance to and physical dependence on morphine. CTS inhibited morphine-6 dehydrogenase, which catalyzes production of mophinone from morphine, and increased hepatic glutathione level responsible to toxicity. Therefore, wehypothesized that these dual actions of ginseng can be associated with the detoxication of morphine. In addition, the inhibitory or facilitated effects of GTS on electrically evoked contraction in guinea pig ileum (${\mu}$-receptors) and mouse vas deferens(${\delta}$-receptors) were not mediated through opioid receptors, suggesting non-opioid mechanisms. On the hand, antagonism of U-50,488H (${\kappa}$-agonist)-induced antinociception is mediated by serotonergic mechanisms. GTS also inhibited hyperactivity, reverse tolerance (sensitization) and conditioned place preference-induced by psychostimulants such as methamphetamine, cocaine and morphine. On the other hand, GTS reduced the dopamine levels induced by methamphetamine. Moreover, GTS blocked the development of dopamine receptor activation, showing antidopaminergic effect. We suggest that GTS prevent the methamphetamine-induced striatal dopaminergic neurotoxicity. In addition, Ginsenoside also attenuates morphine-induced CAMP signaling pathway. These results suggested that GTS might be useful for the therapy of the adverse actions of drugs with abuse liability.

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.79-87
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• 1986

Recently it has been shown that central dopaminergic system regulates the renal function and that intracerebroventricularly (icv) administered dopamine (DA) produces antidiuresis and antinaturiuresis, resembling icv norepinephrine, and evidence has been accumulated which would suggest the involvement of adrenergic system in the DA effects. It was attempted therefore in this study to see whether the DA effect is influenced by pretreatment of yohimbine which is known as a specific ${\alpha}_2-adrenoceptor$ antagonist. Yohimbine produced, when given icv in doses of $100\;{\mu}g/kg$, marked antidiuresis and antinatriuresis along with decreases in renal perfusion and glomerular filtration. DA, in doses of $15\;{\mu}g/kg$, also produced antidiuresis and antinaturiuresis. However, after yohimbine-pretreatment DA $15\;{\mu}g/kg$ improved renal hemodynamics, and electrolyte excretion and urine flow rate transiently increased. With $150\;{\mu}g/kg$ DA, the antidiuresis was more marked in the control group. But the yohimbine-pretreated animals responded with marked diuresis and natriuresis, sodium excretion increasing more than three-fold, which lasted for 20 minutes. $K^+-excretion$, osmolar clearance as well as free-water reabsorption increased. Renal hemodynamics improved partly. Apomorphine, a DA agonist, when given icv in doses of $150\;{\mu}g/kg$, produced diuresis and naturiuresis, concomitant with increased renal hemodynamics. Yohimbine-pretreatment however did not abolish the apomorphine-induced diuresis and naturiuresis. Antidiuresis and antinatriuresis elicited by norepinephrine, $10\;{\mu}g/kg$, was not affected by yohimbine-pretreatment. These results indicate that the renal effects of icv DA is not so simple as those of norepinephrine, and the diuretic natriuretic cffect which had been masked by the hemodynamic effect becomes manifest only when the decreases in hemodynamics were removed by the pretreatment of yohimbine. It was further suggested that those DA receptors which mediate the natriuretic response to icv DA is not affected by yohimbine, whereas those receptors involved in the decrease in renal hemodvnamics are blocked by yohimbine. And the possibility of involvement of adrcnergic system in the DA action is not substantiated.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.11a
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• pp.14-40
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• 2002

15-Deoxy-${\Delta}^{12, 14}$-prostaglandin $J_2$ (15-deoxy-$PGJ_2$), a naturally occurring ligand activates the peroxisome proliferator-activated $receptor-{\gamma}(PPAR-{\gamma}$). Activation of $PPAR-{\gamma}$ has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-$PGJ_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-$PGJ_2$ (0.2 to 1.6 ${\mu}M$) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/ml). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-$PGJ_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-$PGJ_2$(0.8 ${\mu}M$) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-$PGJ_2$ on the expression of p38 MAP kinase and activation of AP-1, The promoting ability of 15-deoxy-$PGJ_2$ did not occur through $PPAR-{\gamma}$, as synthetic PPAR-${\gamma}$ agonist andantagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), $PPAR-{\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and $PGE_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of f 5-deoxy-$PGJ_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-$PGJ_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 single pathway may be important in the promoting activity of 15-deoxy-$PGJ_2$ cells.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.14-40
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• 2002

15-Deoxy- Δ$\^$12,14/-prostaglandin J$_2$ (15-deoxy-PGJ$_2$), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$). Activation of PPAR-y has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-PGJ$_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-PGJ$_2$ (0.2 to 1.6 ${\mu}$M) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/$m\ell$). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-PGJ$_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-PGJ$_2$ (0.8 ${\mu}$M) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-PGJ$_2$ on the expression of p38 MAP kinase and activation of AP-1. The promoting ability of 15-deoxy-PGJ$_2$ did not occur through PPAR-${\gamma}$, as synthetic PPAR-${\gamma}$ agonist and antagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), PPAR-${\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and PGE$_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of 15-deoxy-PGJ$_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-PGJ$_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 signal pathway may be important in the promoting activity of 15-deoxy-PGJ$_2$ on the differentiation of PC12 cells.

• The Korean Journal of Pharmacology
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• v.21 no.1
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• pp.49-61
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• 1985

In view of the facts that dopamine (DA) when given directly into a lateral ventricle (i.c.v.) of the rabbit brain induces antidiuresis and that haloperidol, a non-specific antagonist of DA receptors, produces anti-diuresis in smaller doses and diuresis and natriuresis in larger doses, the present study was undertaken to delineate the roles of various DA receptors involved in the center-mediated regulation of renal function. Bromocriptine (BRC), a relatively specific agonist of D-2 receptors and at the same time a D-,1 antagonist, elicited natriuresis and diuresis when given i.c.v. in doses ranging from 20 to 600 {\mu}g/kg$, roughly in dose-related fashion, while the renal perfusion and glomerular filtration progressively decreased with doses, indicating that the diuretic, natriuretic action resides in the tubules, not related to the hemodynamic effects. These diuresis and natriuresis were most marked with 200 ${\mu}g/kg$, with the fractional sodium excretion reaching about 10%. With 600 ${\mu}g/kg$, however, the diuretic, natriuretic action was preceded by a transient oliguria resulting from severe reduction of renal perfusion, concomitant with marked but transient hypertension. When given intravenously, however, BRC produced antidiuresis and antinatriuresis along with decreases in renal hemodynamics associated with systemic hypotension, thus indicating that the renal effects produced by i.c.v. BRC is not caused by a direct renal effects of the agent which might have reached the systemic circulation. In experiments in which DA was given i.c.v. prior to BRC, 150 ${\mu}g/kg$ DA did not affect the effects of BRC (200 ${\mu}g/kg$), while 500 ${\mu}g/kg$ DA abolished the BRC effect. In rabbits treated with reserpine, 1 mg/kg i.v.,24 h prior to the experiment, i.c.v. BRC could unfold its renal effects not only undiminished but rather exaggerated and more promptly. In preparations in which one kidney is deprived of nervous connection, the denervated kidney responded with marked diuresis and natriuresis, whereas the innervated, control kidney exhibited antidiuresis. These observations suggest that i.c.v. BRC influences the renal function through release of some humoral natriuretic factor as well as by increasing sympathetic tone, and that various DA receptors might be involved with differential roles in the center-mediated regulation of the renal function.