Increase of protein synthesis in cell-free system prepared from hypertrophied rat heart during L-triiodothyronine treatment.

ABSTRACT

During development of rat heart hypertrophy induced by repeated injections of triiodothyronine (T3), cell-free protein synthesis activities of heart post-ribosomal supernatant and of heart polysomes have been measured separately. This was done by complementation respectively with polysomes and post-ribosomal supernatants of adult and newborn rat heart, and of rabbit reticulocytes. In the presence of polysomes of either rat heart or reticulocytes, protein synthesis activity of the supernatant was maximum between the 3rd and the 8th day of treatment. Protein synthesis in the presence of polysomes from triiodothyronine treated rat hearts and of supernatants of both origins was maximum between the 11th and the 15th day.