Effect of external potassium concentrations, insulin and lactate on frog muscle potassium and respiratory rate

Authors:

Abstract
In Ringer's solution containing 10 mEq K/l., frog muscles consumed oxygen at 20°C at rates ranging from 88 (summer frogs) to 128 (winter frogs) cu mm/gm/hr. These rates, which were three to four times higher than those at 2 and 6 mEq K/l., continued to rise for at least 6 hours, although the muscles had previously been soaked at 5°C in the type of Ringer's in which they respired. Addition of lactate increased the respiratory rate at all K concentrations studied. When insulin was present a marked additional stimulation was observed at 2 and 6 mEq K/l., which was changed to an inhibition at 10 mEq/l. Potassium analyses of all of the environmental fluids and of the muscles (144 of each) demonstrated a slight K loss from control muscles which was reduced or abolished by lactate. Insulin, however, either with or without added lactate, abolished the K loss and induced an appreciable K uptake. This K gain occurred regardless of the effect of insulin on the respiratory rate. Denaturation of the insulin abolished all of its effect. Seasonal differences were noted.

This publication has 11 references indexed in Scilit: