In experiments performed on the anterior tibial muscle of white rats under in situ conditions it was established that experimental hyperthyroidism associated with shortening of latent period of the muscle excitation (-26%) and with elevation of the anterior tibial muscle “M-response” amplitude (+23%). Whereas experimental hypothyroidism led to opposite effects — duration of the latent period of the muscle excitation increased (+21%), while “M-response” amplitude decreased (-19%).
