Secreted by the anterior pituitary under stimulation from Growth hormone-releasing hormone(GHRH) and with feedback by Somatostatin, Ghrelin and IGF-I(insulin-like growth factor-I) it acts on adipose cell receptors directly to affect lipid metabolism but mainly acts by stimulating IGF-I secretion from tissues such as the liver. Growth hormone receptor is expressed most in the liver and cartilage. It is likely this mitigates growth hormone deficiency, either because of disease in the hypothalamus-pituitary axis or due to mutants of the hormone or GHRH that render it dysfunctional.
Lifetime deficiency states are manifest by:
- Short stature
- Growth retardation
Phenotype can be variable and more complex than just this. Investigation of some GH mutations has revealed that abnormal GH can affect the production of other pituitary hormones and hence pituitary function. .
Although deficiency can be associated with the pathologies of early aging
life span in man appears to be enhanced typically to ages of 80-90 years..
- ↑ Mullis PE, Robinson IC, Salemi S, EblÃ© A, Besson A, Vuissoz JM, et al. Isolated autosomal dominant growth hormone deficiency: an evolving pituitary deficit? A multicenter follow-up study. The Journal of clinical endocrinology and metabolism. 2005;90:2089-96.
- ↑ Laron Z. Do deficiencies in growth hormone and insulin-like growth factor-1 (IGF-1) shorten or prolong longevity? Mech Ageing Dev. 2005;126(2):305-7.