An evaluation of the functions of the 22-kilodalton (kDa), the 20-kDa, and the N-terminal polypeptide forms of human growth hormone using transgenic mice.
Endocrinology
; 130(1): 405-14, 1992 Jan.
Article
en En
| MEDLINE
| ID: mdl-1727714
Multiple peptide hormones can be derived from the single human GH gene. In addition to the full-length 191-amino acid 22-kilodalton (kDa) form, a 20-kDa variant can be produced by alternative splicing, and a 5-kDa variant can be produced by posttranslational cleavage. To more fully appreciate the physiological roles of these proteins, we have made a comparison of transgenic mice that constitutively overexpress one or another of these variants. We have found that both the 22-kDa and the 20-kDa forms of human GH stimulate linear growth and liver hypertrophy. The increase in linear growth in 22-kDa transgenic mice does not, however, correlate with an increase in circulating IGF-I; rather, the increase in IGF-I that does finally occur correlates with marked liver pathology. Both groups of mice also develop glomerulosclerosis and suffer from hyperinsulinemia. Although there are histologically obvious lesions in the livers of both the 22-kDa and the 20-kDa transgenic mice, only the former exhibit hyperalbuminemia and hypercholesterolemia. Both forms of GH lead to anemia, which is normocytic in the 20-kDa transgenic mice and macrocytic in the 22-kDa transgenic mice. Despite the presence of high levels of the 5-kDa N-terminal form of human GH, the transgenic mice that express this protein are indistinguishable from their nontransgenic littermates.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
/
Hormona del Crecimiento
Límite:
Animals
Idioma:
En
Revista:
Endocrinology
Año:
1992
Tipo del documento:
Article
Pais de publicación:
Estados Unidos