| Abstract: | It has been shown that the modulation of the mechanical properties of sarcolemma mediated by nifedipine may be related to
the dynamics of accumulation of calcium ions under short-term rat hindlimb suspension. The basal calcium level was measured
with a fluorescent probe Fluo-4AM, the transverse stiffness of different parts of the contractile apparatus and sarcolemma
was estimated by atomic force microscopy, and the content of desmin was determined by gel electrophoresis with immunoblotting.
It has been found that nifedipine has a protective effect on muscle fibers under hypogravity by decreasing the degradation
of desmin and proteins that determine the transverse stiffness of sarcolemma and the contractile apparatus, and the intensity
of the increase in the basal calcium level. It was shown that selective blocking of L-channels leads to an increase in the
basal calcium level in intact soleus fibers. At the same time, the transverse stiffness of sarcolemma and the contractile
apparatus increases. The mechanism of this increase is still unclear, but it is thought to mediate the protective action of
nifedipine. |
