• Title/Summary/Keyword: dopamine receptor

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Role of Dopamine on Motility of Duodenal bulb in rabbits (토끼 십이지장구의 운동성에 미치는 dopamine의 영향)

  • Lee, Yun-Lyul;Shin, Won-Im;Park, Hyoung-Jin
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.192-198
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    • 1986

  • The present study was undertaken to see an interaction of dopamine and cholecystokinin on spontaneous contractility of the small intestine including the duodenal bulb. A possible neural mechanism of the interaction was alto examined. The spontaneous isometric contractility of a segment of the duodenal bulb, duodenum, jejunum and ileum obtained from the rabbit anesthetized with ether was recorded in a chamber filled with Krebs-Ringer's solution. The solution was constantly kept at $37^{\circ}C$ and aerated with $O_2$ containing 5% $CO_2$. After 20 min from beginning of the contraction, dopamine $(10^{-4}M)$, CCK-8($10^{-8}M$), domperidone($10^{-5}M$) and tetrodotoxin ($10^{-6}M$) were administered into the chamber The following results were obtained by analyzing changes in the contractility of the intestinal segments. 1) Dopamine inhibited the spontaneous contractility of the duodenal bulb, duodenum, jejunum and ileum. The inhibitory action of dopamine on all parts of the small intestine except the ileum was reduced by tetrodotoxin. 2) Domperidone knwon to be a specific peripheral dopamine receptor antagonist blocked the inhibitory action of dopamine on all parts of the small intestine. The antagonistic action of domperidone on all parts of the small intestine except the ileum was completely abolished by tetrodotoxin. 3) CCK-8 reduced the inhibitory action of dopamine on all parts of the small intestine. The effect of CCK-8 on the dopamine action was diminished by tetrodotoxin. These results suggest that dopamine inhibits the spontaneous contractility of the small intestine including the duodenal bulb and CCK-8 reduces the inhibitory action of dopamine through the enteric nervous system.

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Inhibition of glycine on morphine-induced hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity in mice

  • Shin, Kyung-Wook;Baik, Jong-Won;Hong, Jin-Tae;Shin, Im-Chul;Oh, Ki-Wan
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.152.2-153
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    • 2003

  • We examined the effects of glycine on the morphine-induced hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity in mice. A single administration of morphine (10 mg $kg^{-1}$ s.c.) induced hyperactivity as measured in mice. The morphine-induced hyperactivity aws inhibited dose-dependently by the pretreatment with glycine(100, 200 and 400 mg $kg^{-1}$ i.p.). (omitted)

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Regulation of c-fos promoter through interaction between dopamine D3 receptor and RGL, ral GDP dissociation stimulator-like

  • Park, Ju-Ran;Kim, So-Young;Kim, Kyeong-Man
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.89.2-89.2
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    • 2003

  • Ral GDP dissociation stimulator (Ral GDS) has been found to be an effector protein of Ras, and Ral, a member of small GTP-binding protein (G protein) superfamily, has been suggested to act downstream of Ras. Ral GDP dissociation stimulator-like (RGL) shares 50% amino acid identity with Ral GDP dissociation stimulator, and assumed to possess similar functional role. Using yeast two-hybrid screening, we found that dopamine D3 receptor interacts with RGL. Since RGL is known to regulate the expression of c-fos promoter, effects of D3R on gene expression of c-fos promoter was studied. (omitted)

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