Searchable abstracts of presentations at key conferences in endocrinology
Endocrine Abstracts (2010) 21 S2.3

SFEBES2009 Symposia New endocrinology of bone (4 abstracts)

Ghrelin and ghrelin signaling in bone metabolism

Hans van Leeuwen


Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands.


GH levels decline with aging and this is thought to contribute to the age-related decrease in bone mass. However, data on the effects of GH replacement on osteoporosis are contradictory. The potential therapeutic benefits depend on the dose, frequency and duration of treatment. It is for this reason that treatments with GH secretagogues (GHS), which stimulate pulsatile release of GH as occurs in normal physiology, have been postulated to be a more successful therapeutic approach. GHS are a class of synthetic compounds that can stimulate GH secretion both in vivo and in vitro. Both peptidyl and non-peptidyl GHS’ have been characterized and differ in their effects on bone formation and resorption.

In 1996 the GH secretagogue receptor (GHS-R) was discoverd, for which a few years later the natural ligand ghrelin was identified. Stomach-derived ghrelin stimulates GH release by activating the GHS-R in the pituitary and hypothalamus. GH secretagogue activity is, however, not ghrelin’s major activity since mice deficient for ghrelin or its receptor are not dwarves. Moreover, ghrelin exerts metabolic effects by regulating appetite, feeding and energy homeostasis through central interaction with the satiety hormone leptin.

Like the GHS, ghrelin may affect bone metabolism through its effects on GH secretion. However, infusion of ghrelin into GH-deficient rats increased their bone mineral density (BMD). The concentrations of ghrelin used did not evoke a rise in body weight and food intake excluding possible indirect effects on BMD of ghrelin through its orexigenic activity. This study indicated direct effects on bone cells, which was corroborated by studies on isolated osteoblasts. The recent developments on ghrelin in bone metabolism and bone cell function will be discussed.

Article tools

My recent searches

No recent searches.

My recently viewed abstracts