Time course of the response to recombinant growth hormone in acidotic mice.

Long-term administration of recombinant growth hormone (GH) increases growth, despite persistent acidosis, in mice with carbonic anhydrase II deficiency (CAD). In contrast, short-term administration of GH to acidotic rats fails to improve growth. To determine the factors affecting the rate of growth response to GH in acidosis, we analyzed serial measurements obtained during a randomized trial of GH in CAD mice and healthy controls. Administration of GH increased standardized growth progressively up to 5-9 weeks. These data suggest that assessment of the response to GH in rodents requires prolonged administration.