• 제목/요약/키워드: dopamine receptor supersensitivity

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Ginseng Saponins Prevent the Adverse Effect of Dependence-liable Drugs

  • Kim, Hack-Seang;Lim, Hwa-Kyung
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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    • pp.168-173
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    • 1998
  • A single administration of cocaine (CO), morphine (MOR) and methamphetamine (MA) showed hyperactivity in mice. Ginseng total saponin (GTS), ginsenosides Rbl and Rgl inhibited the hyperactivity induced by the drugs. The repeated administration of CO, MOR and MA showed the development of psychological dependence showing a.: the development of conditioned place preference (CPP) in mice and the development of dopamine (DA) receptor supersensitivity showing as sensitization of the drugs. GTS and Rgl inhibited the development of not only psychological dependence but also of DA receptor supersensitivity induced by CO and MA Rbl prevented also the development of psychological dependence and DA receptor supersensitivity induced by CO and MA but not by MOR. These results suggest that the development psychological dependence induced by the drugs is closely related with the development of DA receptor supersensitivity since both phenomena were inhibited by them. Apomorphine induced climbing behavior was also inhibited by G75 but not by both of Rbl and Rgl, indicating that GTS modulate dopaminergic action at both of pre and postsynaptic sites, but both of Rbl and Rgl , only at the presynaptic site. These results suggest that active components acting at the postsynaptic site exist in GTS. In this study, it was found that GTS, ginsenosides Rbl and Rgl inhibited tyrosine hydroxylase (TH) and these components exerted inhibitory effects on both Cal' currents and $\Delta$ Cm in rat adrenal chromaffin cells. These results suggest that G75 and ginsenosides regulate catecholamine synthesis and secretion. Meanwhile, it has been demonstrated that Rbl, at high doses has more powerful inhibition of cartecholamine secretion at the presynaptic site than Rbl. Therefore, it was presumed that inhibition of morphine induced psychological dependence by Rgl, but not by Rbl results from differences in the extent of this inhibitory action on dopaminergic synthesis and secretion.

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일측성선조체의 6-OHDA손상 후 도파민효능약물 투여로 발현된 회전운동의 특성

  • 이순철;문민선
    • Journal of Ginseng Research
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    • 제21권1호
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    • pp.61-67
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    • 1997
  • The present study examined the characteristics of behavior Induced by dopamine agonists following treatment with 6-hydroxydopamine(6-OHDA) unilaterally into left striatum in rats. 6-OHDA was administered at doses of 8,16 and 24 $\mu\textrm{g}$/$\mu\textrm{l}$(in 0.1% ascorbic acid) into dopaminergic neurons in left striatum of 7 weeks old rat under anesthetic. Locomotor activity was significantly decreased at 1 week following 6-OHDA-administration in 7 weeks old rats. The contralateral circling behavior was induced by apomorphine(5 mg/kg, i.v.) after 1 week following 6-OHDA(24$\mu\textrm{g}$/$\mu\textrm{l}$) treatment, and was further increased by repeated administration of apomorphine at 2, 3 and 4 weeks. The contralateral circling behavior was also induced by lisuride and 1-dopa in a dose dependent manner, but not by SK & F 82526 in 7 weeks old rats treated with 6-OHDA. The contralateral circling behavior was significantly higher in 21 weeks old rats but significantly lower In 35 weeks old rats when compared with 7 weeks old rats. The contralateral circling behavior induced by apomorphlne did not differ significantly in 7 and 35 weeks old male and female rats. These results suggest that 6-OHDA treatment into left striatum causes remarkable destrurtion of intrastriatal dopaminergic netcons leading to dopaminergic receptor supersensitivity. Thus, the contralateral circling behavior in duces by apomorphine may be used as indicator for neurodegenerative diseases.

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Inhibitory Effect of Bacopa monniera on morphine Induced Pharmacological Effects in Mice

  • Balakrishna, K.;Veluchamy, G.;Devaraj, S. Niranjali;Sumathi, T.
    • Natural Product Sciences
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    • 제13권1호
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    • pp.46-53
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    • 2007
  • The effects of the alcoholic extract of Bacopa monniera (BMA) on morphine-induced pharmacological activities were studied in mice. Oral administration of the extract (40 mg/kg) significantly inhibited morphine-induced analgesic tolerance, withdrawal symptoms, hyperactivity, reverse tolerance, Dopamine receptor supersensitivity and apo-morphine-induced climbing behaviour in mice. The results of this study showed that, alcoholic extract of Bacopa monniera (BMA) exerted inhibitory effect against morphine-induced pharmacological effects, suggesting that the extract could be useful in the treatment of morphine toxicity.