척추동물 망막에서 아연과 저온 효과가 명·암순응에 미치는 영향

• 영문명: Effects of Zinc and Hypothermic Process during the Light and Dark Adaptation of Vertebrate Retina
• 발행기관: 대한안과학회
• 저자명: 박종석 김현정 정혁 김상기 최귀향 김보애 서태수 김상국 김유영 김시열
• 간행물 정보: 『대한안과학회지』Ophthalmological Society,volume48,number7, 969~979쪽, 전체 11쪽
• 주제분류: 의약학 > 기타의약학
• 파일형태: PDF
• 발행일자: 2007.07.31

영문 초록

Purpose: The purpose of this study was to clarify the effects of zinc treatment and hypothermia on visual adaptation and visual sensitivity in bullfrogs (Rana catesbeiana), which are poikilothermal animals capable of adjusting quickly to environmental temperature changes. Methods: The effects of both zinc treatment and hypothermia on visual sensitivity were studied by using electroretinogram (ERG) recording and absorption spectra scanning before and after zinc and TSQ (N-[6-methoxy-8-quinolyl]-p-toluene sulfonamide) treatment, with or without temperature changes. Results: In spite of malnutrition due to hibernation, the optimal zinc concentration effect was obtained at 10-4 M (10-2 M 200 ㎕ ZnCl2 in 20 ㎖ Ringer’s solution) according to ERG recording. After zinc treatment and hypothermia induction, increments of all ERG components and thresholds were taken by ERG recording. These results showed that both zinc treatment and hypothermia may increase visual sensitivity during visual adaptation. In spectral scans, the absorbance increment due to zinc treatment and hypothermia was shown over the whole spectral range (400~750 nm), and it was especially prominent at α-peak (about 500 nm). In addition, there was a decrease in absorption differences between dark adaptation and light adaptation after zinc treatment. Furthermore, according to the visual sensitivity decrement using TSQ as a zinc specific chelator, this visual sensitivity increase was shown to be caused by zinc. Conclusions: As the results suggest, both zinc treatment and hypothermic effects may improve visual sensitivity by promoting rhodopsin regeneration and inhibiting rhodopsin bleaching induced by light illumination. Zinc may activate the enzyme activity of retinol dehydrogenase and phosphodiesterase, while hypothermic effects may improve precursor transport, which is required for rhodopsin regeneration, by tightening membrane adhesion between retinas and retinal pigment epithelia. In addition, we believe that zinc treatment and hypothermic effects may work synergistically to accelerate visual sensitivity during visual adaptation.

키워드

Absorption Spectra Scanning, Hypothermic Effect, Electroretinogram (ERG), TSQ (N-[6-methoxy-8-quinolyl]-p-toluene sulfonamide), Zinc