Abstract
In intact adult dogs of both sexes exogenous growth hormone induced a marked increase in new bone formation. The net effect on resorption could not be defined quantitatively but endosteal resorption was decreased. Intracortical resorption was increased but intracortical porosity rose only slightly. In addition to the decrease in endosteal resorption, there was abundant endosteal new bone formation. This rise in endosteal new bone formation plus the marked stimulus to periosteal new bone formation led to a net increase in skeletal mass. The bone formed was normal histologically and microradiographically. Despite a marked rise in new bone formation, alkaline phosphatase values remained unchanged.