Weight Variations of Adrenalectomized Frog Muscles in Different Concentrations of Ringer's Solutions. ∗

Summary

Ileofibularis, sartorius and semitendinosus muscles were obtained from 4 groups of grass frogs: 1) “controlled” adrenalectomized; 2) “uncontrolled” adrenalectomized; 3) renal damaged (controls); and 4) unoperated (controls) frogs. These muscles were studied with regard to changes in their initial weights following predetermined periods of immersion either in hypotonic, isosmotic or in hypertonic Ringer's solution. The rates of increase and the total gain in weights of muscles from the 4 frog groups following the immersion of the muscles in hypotonic (50%) Ringer's solution are highest for the “controlled” adrenalectomized frogs, lowest for the “uncontrolled” adrenalectomized frogs. The same muscle groups when studied in hypertonic (2X) Ringer's solution give results inversely related to the foregoing values. In normal Ringer's solution, muscles from the “uncontrolled” adrenalectomized frogs lose water, those from “controlled” adrenalectomized, renal damaged and unoperated frogs behave normally by increasing their weights. These results are interpreted on the basis of the difference in the initial water loads of the skeletal muscle of the respective groups of frogs which are known to exist prior to experimental use.