THE EFFECT OF BOUND INSULIN ON THE RESPIRATORY RATE AND ELECTROLYTES OF INTACT FROG MUSCLE

Abstract

Isolated frog muscles were immersed in Ringer's solution containing insulin, for varying periods of time from 5 to 40 minutes; following this procedure they were washed, with varying degrees of intensity, in insulin-free Ringer's solution. Contralateral muscles were treated similarly with insulin-free Ringer's solution. The muscles then respired in Warburg vessels in the presence of lactate for 6 hours, at which time the media in the Warburg vessels were analyzed for potassium and phosphate and the muscles for water and sodium. Data from paired muscles were always compared. Results from several experimental designs led to the conclusion that insulin was held in some way to the muscle and was carried over into the Warburg vessel since marked stimulation of respiratory rate, potassium and phosphate uptake, and sodium loss were observed. Extensive washing did not remove the bound insulin. No greater effect of insulin was observed when it was bound at a pH of 7.6 than at a pH of 6.0.