The thyroid control of the excitability of a skeletal muscle of white rats (research in situ)

Abstract

It has been shown in experiments in situ, that the latent period of the generation of „M-response” of a m. tibialis anterior of white rats is shortened for 35% at a condition of experimental hyperthyroidism of easy degree of expressiveness, and, on the contrary, it is extended for 46% at a condition of experimental thyrotoxicosis. Within of the physio­logical concentrations of free triiodothyronine (2.4–7.3 pmol/l) the dependence between the level of a hormone and duration of the latent period of M-response generation of rats of euthyroid group has linear character at negative values of coefficient of regression and correlation. The linear dependence gains the inverse character at experimental hyperthyroidism and thyrotoxicosis (within of the concentration of a hormone from 8 to 19 pmol/l). It is supposed, that within of the concentration of free triiodothyronine 10.0–11.0 pmol/l it is been the point of switching of the physiological mechanism of regulation of excitability of a skeletal muscle on the pathophysiological one.

Keywords

• skeletal muscle
• m-response
• hyperthyroidism
• thyrotoxicosis