THE NEW FINDING OF A LIGHT DEPENDENT $Ca^{2+}$ CHANNEL AND $Na^+-Ca^{2+}$ EXCHANGER IN THE VERTEBRATE RETINA (II)

  • Kim, Yun-Sook (Department of Biochemistry, College of Natural Sciences Kyungpook National University) ;
  • Jung, Hyuk (Department of Biochemistry, College of Natural Sciences Kyungpook National University) ;
  • Park, Chang-Suck (Department of Biochemistry, College of Natural Sciences Kyungpook National University) ;
  • Woo, Suk-Hyang (Department of Biochemistry, College of Natural Sciences Kyungpook National University) ;
  • Kim, Hyun-Jung (Department of Biochemistry, College of Natural Sciences Kyungpook National University) ;
  • Kim, You-Young (Department of Biochemistry, College of Natural Sciences Kyungpook National University)
  • Published : 1996.09.01

Abstract

Calcium modulates the activity of guanylate cyclase and plays a key role in dark and light adaptation in the visual system. We have measured the Ca$^{2+}$, K$^+$ and Na$^+$ concentration in dark and light adapted bullfrog's (Rana catesbeiana) vitreous humor by using the atomic absorption spectrophotometer. The calcium concentration of the light adapted bullfrog's vitreous humor was higher than that of the dark adapted bullfrog's vitreous humor. This means that ion activity between the photoreceptor and vitreous humor side is light dependent and we have found that a Ca$^{2+}$ channel and Na$^+$ - Ca$^{2+}$ exchanger exist in the vitreous humor.

Keywords

References

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