Gh-KO Mouse

GH, short for growth hormone, is a peptide hormone. It can signal directly via its receptor or indirectly through insulin-like growth factor 1 (IGF-1) stimulation. GH has anabolic effects on muscle and bone, and also exerts distinct metabolic effects in multiple tissues. It is closely associated with aging, with levels declining as individuals age, and its action negatively correlating with lifespan. The GH-IGF axis is crucial in promoting human growth [1,2].

GH knockout (GH-/-) mice have been created and characterized. These mice have severely decreased IGF-1 levels, small body size, and altered body composition with increased adiposity. They are extremely insulin-sensitive but glucose-intolerant, with a reduced pancreatic islet size. GH-/-mice show depot-specific effects on white adipose tissue (WAT), with subcutaneous WAT having larger adipocytes and reduced fibrosis, indicating GH has a more pronounced effect on subcutaneous WAT. These mice are also responsive to GH treatment, as shown by changes in serum IGF-1 levels, body length, weight, composition, and insulin sensitivity [5].

In conclusion, GH is fundamental in skeletal growth during puberty and bone health throughout life. It also plays important roles in cardiac growth, myocardial contractility, and the vascular system. The study of GH-/-mouse models has revealed its role in body composition, metabolism, and adipose tissue characteristics, providing insights into diseases related to growth and metabolism such as osteoporosis, chronic heart failure, and metabolic disorders associated with GH deficiency or excess [1,3,4].