[Slow calcium waves in cultured postnatal rat skeletal myocytes].

A variety of active agents increasing [Ca2+]i in cultivated skeletal myocytes have been investigated. It was shown that, out of the agents such as noradrenaline, carbacholine, caffeine, cyclopiazonic acid, and potassium solution, only the last caused the formation of slow calcium waves in skeletal myocytes. These waves propagated not only near the location of the cell nucleus but also along the whole length of myocytes.

[Effect of low-intensity magnetic fields on the development of satellite muscle cells of a newborn rat in the primary culture].

The influence of Earth magnetic field shielded down to 0.3 microT and static magnetic field (60-160 microT) on the proliferation and differentiation of satellite muscle cells in the primary culture has been investigated. A stimulatory effect of static magnetic fields on the rate of the formation of massive multinucleated myotubes and an increase in the intracellular calcium concentration ([Ca2+]i) have been detected for magnetic fields of the microtesla range.

[Disturbances in the function of cardiomyocyte ryanodine receptors of spontaneously hypertensive rats revealed by 4-chloro-m-cresol].

The rates of Ca2+ release from sarcoplasmic reticulum in response to the activation of ryanodine receptors by 4-chloro-m-cresol in cardiomyocytes of three rat lines: spontaneously hypertensive (SHR) and normotensive WKY, and Wistar rats during five weeks of their growth and development have been studied to reveal differences in the function of ryanodine receptors at different stages of hypertension. Whereas the efflux of Ca2+ from sarcoplasmic reticulum in Wistar and WKY rat cardiomyocytes decreased in response to 4-chloro-m-cresol, an abrupt rise in the rate of [Ca2+]i increase was observed in myocytes of spontaneously hypertensive rats after 17 days of development. A correlation between this phenomenon and the occurrence of genetic defect of ryanodine receptors in SHR seems improbable because we did not register any differences in the rates of Ca2+ release from sarcoplasmic reticulum by the action of 4-chloro-m-cresol in concentrations 0.