Ornithine decarboxylase activity and actin polymerization in testosterone--stimulated mouse kidney

Renal hypertrophy was induced in mice by injection of testosterone. Associated with an increase in renal tissue mass were increases in the concentrations of spermine and spermidine and in the activity of ornithine decarboxylase (ODC), the rate limiting enzyme in their synthesis. The increased activity of ODC was shown to be due to an increase in tissue ODC content. Total tissue actin was not altered by testosterone treatment although the proportion of unpolymerized (soluble) actin was increased significantly. These data are discussed in relation to the postulated mechanism of polyamine stimulation of actin polymerization.