Ghrelin secretion stimulated by β1-adrenergic receptors in cultured ghrelinoma cells and in fasted mice

TJ Zhao, I Sakata, RL Li, G Liang… - Proceedings of the …, 2010 - National Acad Sciences
TJ Zhao, I Sakata, RL Li, G Liang, JA Richardson, MS Brown, JL Goldstein, JM Zigman
Proceedings of the National Academy of Sciences, 2010National Acad Sciences
Ghrelin, an octanoylated peptide hormone produced in the stomach, rises dramatically in
mouse plasma during chronic severe calorie deprivation, an event that is essential to
maintain life. The mechanism for this increase is not understood. Here, we study the control
of ghrelin secretion in tissue culture cells derived from mice bearing ghrelinomas induced by
a tissue-specific SV40 T-antigen transgene. We found that the ghrelin-secreting cells
express high levels of mRNA encoding β1-adrenergic receptors. Addition of norepinephrine …
Ghrelin, an octanoylated peptide hormone produced in the stomach, rises dramatically in mouse plasma during chronic severe calorie deprivation, an event that is essential to maintain life. The mechanism for this increase is not understood. Here, we study the control of ghrelin secretion in tissue culture cells derived from mice bearing ghrelinomas induced by a tissue-specific SV40 T-antigen transgene. We found that the ghrelin-secreting cells express high levels of mRNA encoding β1-adrenergic receptors. Addition of norepinephrine or epinephrine to the culture medium stimulated ghrelin secretion, and this effect was blocked by atenolol, a selective β1-adrenergic antagonist. When WT mice were treated with reserpine to deplete adrenergic neurotransmitters from sympathetic neurons, the fasting-induced increase in plasma ghrelin was blocked. Inhibition was also seen following atenolol administration. We conclude that ghrelin secretion during fasting is induced by adrenergic agents released by sympathetic neurons and acting directly on β1 receptors on the ghrelin-secreting cells of the stomach.
National Acad Sciences