Roentgen cephalometric studies on skull development in rats. III. Gigantism versus acromegaly: age differences in response to prolonged growth hormone administration.

Experimental conditions simulating the induction of clinical pituitary gigantism and acromegaly were established by prolonged administration of growth hormone in high dosage to adult male rats starting at two different ages: 6 months (growth still active) and 14 1/2 months (growth virtually arrested). Treatment continued for 14 1/2 months, control receiving saline injections. Each group numbered eight at onset.