ABSTRACT
Ribonuclease activity in thymus and lymph nodes is stimulated by cortisone; insulin increases ribonuclease activity only in the thymus. Growth hormone and theophylline do not cause changes in thymus and lymph nodes ribonuclease levels. Injections of cortisone combined with growth hormone or with theophylline increase the activity more than cortisone alone. Insulin does not enhance the action of cortisone on ribonuclease activity. A synergistic loss in weight of thymus and spleen was found after administration of cortisone in combination with either growth hormone or with theophylline.
