Polyamine metabolism in muscles of mice and rats

Polyamine biosynthesis in different types of muscle was studied in mice and rats. A sex difference of polyamine biosynthesis in the gastrocnemius of the mouse was demonstrated. Ornithine decarboxylase activity was found to be several-fold higher in the gastrocnemius of the male mouse than in that of the female. Orchiectomy resulted in a decline of enzyme activity in the gastrocnemius. This effect was reversed by the administration of testosterone. The elevation of ornithine decarboxylase activity in the gastrocnemius by testosterone was reflected in an increased content of the polyamines in the muscle. Muscles of other types, i.e. soleus, heart and urinary bladder were shown to be virtually unresponsive to testosterone treatment. Neither were the muscles of the rat, including gastrocnemius, found to be affected by the androgen.