Age-related changes of myofibrils in white laboratory rats of different ages

Abstract

The study of isolated preparations of experimental white rats of 14 months and older reveals that the longitudinal orientation of cardiomyocytes is replaced by an angular orientation in older mice. The number and structural integrity of myofibrils occupy one of the leading places in the regulation of the contraction-relaxation cycle and the implementation of the adaptive capabilities of the myocardium in the normal functioning of cardiomyocytes. Our experimental studies aim at describing the quantitative a n d m o r p h o l o g i c a l c h a r a c t e r i s t i c s o f m y o f i b r i l s i n r a t s o f t w o a g e g r o u p s a n d a n a l y z i n g t h e morphological and functional results. Isolated heart preparations were examined in two age groups of white rats (middle -8-14 years; elderly -14 months and more. The number of rats in each group amounted to six) using different histological staining methods. The results obtained show that, compared with middle-aged rats, the development of degenerative changes in myofibrils is observed in old rats, which is manifested in structural inferiority and quantitative reduction. Degenerative changes revealed with age at the intracellular level can be considered an important morphological basis for the formation of functional heart failure and the depletion of adaptive capabilities.