TRANSGENIC RABBITS OVEREXPRESSING GROWTH-HORMONE DEVELOP ACROMEGALY AND DIABETES-MELLITUS

Transgenic rabbits expressing the bovine growth hormone (bGH) gene in liver and kidney were obtained to study the long-term effects of chron ic exposure to GH in nonrodent animals, These rabbits presented high l evels of bGH and insulin-like growth factor I in serum. In spite of ch ronic exposure to bGH, transgenic rabbits had similar body weight to c ontrols. However, enlargement of the head and limbs and reduction of v isceral fat were observed in these animals. They also showed marked hy perinsulinemia, hyperglycemia, and hypertriglyceridemia, indicating th at they developed insulin resistance, Furthermore, serious histopathol ogical alterations, including marked fibrosis, were observed in liver, kidney, and skeletal muscle. These anatomical, metabolic, and histolo gical alterations closely resemble those found in patients with acrome galy, Thus, transgenic rabbits overexpressing GH may be a good model o f the human disease.