ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Using paired frog muscles it was shown that fluoride caused no observable change in the rate of oxygen consumption in Ca++-free Ringer's solution, but stimulated the rate in Ca++-containing Ringer's; the obvious explanation for this stimulation is the spontaneous activity of the muscle caused by the rapid lowering of Ca++ ion concentration when fluoride was added. Fluoride had no effect on potassium movement in these experiments. In a Ca++-free solution fluoride (0.03 M) inhibited the insulin + lactate-stimulated oxygen consumption of muscles which had been adapted to the absence of calcium by overnight soaking. In Ca++-containing Ringer's there was no net effect of fluoride, demonstrating the fact that the direct inhibition of oxygen consumption was cancelled by the indirect stimulation caused by the fluoride-lowering of the Ca++ ion concentration. Fluoride depressed the IL-induced K uptake but for this effect some calcium, albeit a very low concentration, was necessary. Fluoride did not alter the muscle glycogen concentrations.The only observable effect of calcium (in the absence of fluoride) was a rise in respiration caused by exposure to a sudden reduction in Ca++ ion concentration. Both the IL-stimulated O2 rate and K uptake were independent of Ca++ ions since they occurred in Ca++-free adapted muscles, in muscles exposed to a rapid reduction of Ca++ ions as well as in muscles in a Ca++-containing Ringer's solution.
Additional Material:
5 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040680106
