Effects of X-irradiation on Papillary Muscle of the Cat

Abstract

A NUMBER of investigations have been carried out on the influence of X-rays on the electrophysiological and mechanical properties of striated muscle^1–5. Most of these experiments have been performed on frog's sartorius muscle, and have revealed the fact that striated muscle generally shows a high X-ray insensitivity. Only minor changes of the membrane resting potential could be recorded during the first few hours following a heavy X-irradiation (80–250 kr.). Similar results were obtained by us (Schliep, H. J., Kraupp, O. and Pillat, B., unpublished results). A 1-mV. decrease of resting potential was produced by an average of 160 kr. (50 kV. 25 m.amp.). Further investigations on the same preparation showed that doses between 300 and 500 kr. practically did not influence intracellular action potentials recorded at 5-min. intervals before, during and after irradiation (Kraupp, O. and Pillat, B., unpublished results).