Regulation of anterior pituitary D2 dopamine receptors by magnesium and sodium ions.
At D2 3,4-dihydroxyphenylethylamine (dopamine) receptors in anterior pituitary tissue, magnesium ions shifted receptors to agonist high-affinity states, but decreased the affinity of the antagonist [3H]spiperone. Conversely, sodium ions shifted the receptors to agonist low-affinity states, but increased the affinity of [3H]spiperone. Magnesium is proposed to stabilize the hormone-receptor-guanine nucleotide regulatory protein complex, whereas sodium appears to destabilize this ternary complex. Thus, magnesium and sodium appear to mediate their regulatory effects via a common component at the D2 dopamine-receptor ternary complex.
Watanabe
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George
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Seeman
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D000818:Animals; D001058:Apomorphine / Q000031:analogs & derivatives / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D006150:Guanine Nucleotides / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D017448:Receptors, Dopamine D2; D012964:Sodium / Q000494:pharmacology*; D013134:Spiperone / Q000378:metabolism; D013552:Swine
D006150:Guanine Nucleotides; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D013134:Spiperone; C009074:N-n-propylnorapomorphine; D012964:Sodium; D008274:Magnesium; D001058:Apomorphine; D004298:Dopamine