Specific effect of 5,6-dihydroxytryptamine on the monoamine fluorophore of the frog's gustatory cells.
A specific formaldehyde-induced yellow fluorescence, suggesting the presence of serotonin-like monoamine has been demonstrated in the gustatory cells of the frog. The fungiform papillae of frogs were examined fluorescence-histochemically after intraperitoneal injection of 5,6-dihydroxytryptamine. The results indicated that the fluorophore of gustatory cells was affected selectively by the drug injection: the yellow fluorescence was transiently enhanced 3 hours after the drug injection, thereafter being reduced rapidly. The effect of 5,6-dihydroxytryptamine was long-lasting with the reduction of the yellow fluorophore persisting at least for the experimental duration of 14 days. A single injection of 6-hydroxydopamine induced a complete depletion of noradrenaline fluorescence from adrenergic nerve terminals, while the fluorescence of gustatory cells was not affected by a high dose of the drug. The present results with pharmacologic treatments further support the view that the gustatory cell of the frog contains a serotonin-like monoamine.
D015115:5,6-Dihydroxytryptamine / Q000494:pharmacology*; D000818:Animals; D001001:Anura / Q000502:physiology*; D001679:Biogenic Amines / Q000032:analysis*; D006892:Hydroxydopamines; D008856:Microscopy, Fluorescence; D009638:Norepinephrine / Q000032:analysis; D011892:Rana catesbeiana; D013564:Sympathetic Nervous System / Q000032:analysis; D013650:Taste Buds / Q000032:analysis*; D014363:Tryptamines / Q000032:analysis* / Q000494:pharmacology*
D001679:Biogenic Amines; D006892:Hydroxydopamines; D014363:Tryptamines; D015115:5,6-Dihydroxytryptamine; D009638:Norepinephrine