[Variations in the resting membrane potential of denervated and tenotomized-denervated rat skeletal muscles]

Resting membrane potential (RMP) was studied in denervated (D), tenotomized (T) and tenotomized-denervated (TD) Soleus (S) and Tibialis Anterior (TA) muscles of the rat. In TD muscles, denervation was performed 1 week after tenotomy. The measurements were performed "in vitro" at 20 degrees C, 1-7 days after denervation in D and TD muscles, and 7 days after tenotomy in T muscles. In T muscles there were not differences in comparison with the controls. In D muscles RMP decreased earlier in S than in TA. The time course of membrane depolarization was similar in TD and D muscles until the 2nd day after denervation. At the 3rd day, RMP showed a further, significant reduction in TD muscles, both in S and TA, but not in D muscles. In D muscles, the depolarization increased very slowly up to the 7th day.