カワムツ黒色素胞に対する情報分子の作用におよぼす二価陽イオンの影響

Using denervated melanophores in isolated scales of the dark chub Zacco temmincki, effects of divalent cations, Ca^<++>, Sr^<++>, Ba^<++>, Mg^<++> and Mn^<++> on responses of the melanophores were investigated.
The Ca^<++> was not required for melanosome aggregation mediated by alpha adrenergic receptors or by melatonin receptors and for melanosome dispersion mediated by beta adrenergic receptors. The Ca^<++> was required for the melanosome-dispersing action of melanophore-stimulating hormone (MSH). Sr^<++>, Ba^<++>, Mg^<++> and Mn^<++> could not replace the Ca^<++>. Mn^<++> reversibly inhibited the action of MSH. These results indicate that the Ca^<++> is the only divalent cation specifically required for MSH action on the melanophores of Z temmincki