growth hormone (GH) • somatostatin • GH-releasing hormone • ghrelin • brain
My research focuses on understanding how the brain controls the secretion of growth hormone (GH), a pituitary hormone that is essential for normal growth and metabolism. The importance of GH in the maintenance of health is demonstrated by the observation that prolonged GH deficiency results in marked alterations in linear growth (eg. dwarfism) and body composition (fat, muscle mass and bone minerals). We have demonstrated that regulation of GH secretion is under the precise control of the brain and is achieved by the complex interaction of two brain hormones, a stimulatory GH-releasing hormone and an inhibitory hormone, somatostatin. Recently, a third independent pathway has emerged with the discovery of a novel hormone, named ghrelin. We showed that ghrelin causes powerful release of GH and also stimulates appetite. The focus of our current research is to determine whether ghrelin plays an important role in the normal physiological regulation of GH secretion or appetite, and to clarify the brain pathways through which ghrelin acts.
Fraser GL, Hoveyda HR, Tannenbaum GS. Pharmacological demarcation of the growth hormone, gut motility and feeding effects of ghrelin using a novel ghrelin receptor agonist. Endocrinology. 2008 Dec;149(12):6280-8. doi: 10.1210/en.2008-0804. Epub 2008 Aug 21. PMID: 18719021.
Tannenbaum GS, Ramsay M, Martel C, Samia M, Zygmuntowicz C, Porporino M, Ghosh S. Elevated circulating acylated and total ghrelin concentrations along with reduced appetite scores in infants with failure to thrive. Pediatr Res. 2009 May;65(5):569-73. doi: 10.1203/PDR.0b013e3181a0ce66. PMID: 19617874.
Stroh T, van Schouwenburg MR, Beaudet A, Tannenbaum GS. Subcellular dynamics of somatostatin receptor subtype 1 in the rat arcuate nucleus: receptor localization and synaptic connectivity vary in parallel with the ultradian rhythm of growth hormone secretion. J Neurosci. 2009 Jun 24;29(25):8198-205. doi: 10.1523/JNEUROSCI.0336-09.2009. PMID: 19553459.
Wagner C, Caplan SR, Tannenbaum GS. Interactions of ghrelin signaling pathways with the GH neuroendocrine axis: a new and experimentally tested model. J Mol Endocrinol. 2009 Sep;43(3):105-19. doi: 10.1677/JME-09-0023. Epub 2009 May 11. PMID: 19433492.
Caplan SR, Tannenbaum GS, Johnstone RM. An enzymatic model of the growth hormone-releasing hormone oscillator incorporating neuronal synchronization. J Theor Biol. 2010 Jun 7;264(3):984-9. doi: 10.1016/j.jtbi.2010.02.042. Epub 2010 Mar 6. PMID: 20211631.