ISSN:
1432-2013
Keywords:
K-, Rb-uptake
;
Ouabain
;
Physostigmine
;
Glycerol treatment
;
Surface membrane
;
Transverse tubules
;
Frog muscle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The influence of ouabain and physostigmine on42K and86Rb uptake in isolated frog sartorii with normal [Na] i (12–14 mmol·kg−1 wet weight) and low [Na] i (6 mmol·kg−1 wet weight) was compared. Both in normal-sodium and in low-sodium muscles application of 10−3 M physostigmine reduces potassium influx by about 70%. About one fourth of potassium-uptake in normal-sodium muscles is inhibited by ouabain (10−4M) and only a very slight fraction of potassium uptake is ouabain-sensitive in low-sodium muscle. The effects of ouabain and physostigmine on42K influx are additive. The greater parts of the Rb-fluxes are through the ouabainsensitive pathway. Glycerol treatment has no effect on ouabain-sensitive channels although it inhibits markedly the K-flux through the physostigmine-sensitive pathway. The results suggest that the Na−K-ATPase is located in the surface membrane while most of the physostigmine-sensitive K-exchange is within the tubules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00658270
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