The mode of action of potassium ions on the leukophores of a freshwater teleost,Oryzias latipes

✍ Scribed by Iga, Tetsuro

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 776 KB
• Volume: 205
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402050310

✦ Synopsis

Abstract

Pigment migration within leukophores of Oryzias latipes (a freshwater teleost) is under nervous regulation. Isotonic KC1 induced pigment dispersion in vitro in innervated leukophores, whereas in most of the denervated leukophores the ionic stimulation did not cause the pigment dispersion within the cells. These results show that K ions act through nervous elements on the leukophores to disperse their pigment granules. Local application of the KC1 solution on a scale indicated that the ions act on the nerve terminals situated close to the leukophores to induce the release of a neurotransmitter causing pigment dispersion in leukophores. A few of the leukophores showed a slight pigment dispersion to the ionic stimulation after denervation. It is inferred from this that K ions act also directly on the pigment cells themselves. The pigment‐dispersing response of innervated leukophores induced by the K stimulation was not all‐or‐none type, but increased in a graded manner with the increase in the K concentration in the medium. The threshold concentration of K ions was about 17.3 mM. Full dispersion of the pigment was brought about with a K concentration above 33.3 mM.