淡水魚における寄生虫に関連して生じたメラノーマの研究(I) : メラノーマ細胞の生理学的性質

1. Individuals possessing dark spots on the skin were found in Oryzias latipes. Microscopic observations revealed that, as has been described in some other fresh-water fishes, the dark spot, melanoma, comprises a mass of pigment cells of branched types, in which an encysted larva of a treamafode(unidentified) is enclosed.
2. The activity of the melanoma cells in the excised skin or a slit strip of fin was investigated. They show active concentration of the pigment in response to adrenaline (10^<-4>−10^<-5>M) applied through the external fluid(physiological solution) of the isolated piece, just as do the usual melanophores in the adjacent areas.
3. The melanoma cells in the isolated piece are also caused to concentrate their pigment entirely in the same manner as do the neighboring melanophores, either by bathing the piece in isotnic (M/7.5) KCl solution or by flowing alternating current through the electrodes placed on the piece. This seems to imply that the melanoma cells have been supplied with pigment-concentrating nerve fibers for the melanophores.
4. Some experiments were done on the melanoma cells in Carassius auratus, infected by larvae of treamatode, Metagonimus takahashii, with similar results.