ISSN:
1432-2013
Keywords:
Isolated Retina
;
External Potassium
;
Retinal Na+-, K+-Content
;
Exposure Potential
;
Flame Photometry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The effect of the external K+-concentration in a range from 0 to 10 mMol/l on the exposure potential (ERG) and the Na+-, K+-distribution in the retinal tissue of Rana esculenta was investigated. After 45 min of perfusion with the test solution moist combustion of the tissue and analysis by flame photometry was carried out. At concentrations of less than 1 mMol/l an extensive loss of retinal potassium could be observed which corresponded to a slow and steady decrease of the exposure potential. Simultaneously the mean intracellular Na+-content increased. Above 2 mMol/l a rapid decline of the potentialΦ b to a constant level was recorded. At the same time there was a slight increase in retinal potassium and a decrease in sodium. The quick transition to steady values of the ERG at high external K+-concentrations is attributed to the limitation of the potassium uptake of retinal cells which brings about a constant distribution of electrolytes in a short time. The slow drop in potential at a low potassium content of the bathing solution is ascribed to the diffusion process of K+ through cellular membranes of the retina.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01023671
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