Activation of the non-actomyosin component of aortic wall contraction by phorbol ester.
The mechanisms of smooth muscle tissue contractile system functioning are in many respects unexplained. According to the existing hypothesis, the mechanism of smooth muscle contraction is based on the interaction between myosin and actin. The change of muscle tissue stiffness during the contractive process is the important and obligatory feature of this actomyosin interaction. Earlier we have shown that, together with the smooth muscle cells, the connective tissue matrix can also produce the active mechanical strength. This process is not accompanied by changes of stiffness. We suggested that in some cases the induced contraction of smooth muscles is fulfilled, entirely or in part, by the connective tissue matrix. We report here that contractive reaction induced by the phorbol ester--activator of protein kinase C, which is one of the most important enzymes involved in the regulation of the smooth muscle contraction--occurs without any stiffness changes. The results obtained can not be explained in terms of the generally accepted hypothesis of actomyosin interaction. The conclusion is made that phorbol ester during the action on the smooth muscle tissue activates the mechanical strength generation by the connective tissue matrix.
Shapovalov
A N
AN
National Biophysical Center, Kiev, Ukraine.
Shuba
M F
MF
D000205:Actomyosin / Q000502:physiology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D010208:Papaverine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004533:Egtazic Acid; D000205:Actomyosin; D010208:Papaverine; D013755:Tetradecanoylphorbol Acetate