Role of pulsatile growth hormone (GH) secretion in the regulation of lipolysis in fasting humans

Clinical Diabetes and Endocrinology

N. Goldenberg¹  A. Sakharova¹  A. L. Barkan²  J. F. Horowitz³  A. Gorgey³ 

[1] Department of Medicine, University of Michigan, Ann Arbor, USA;Departments of Medicine and Neurosurgery, Division of MEND, University of Michigan, 24 Frank Lloyd Wright Drive G-1500, 48106, Ann Arbor, MI, USA;School of Kinesiology, University of Michigan, Ann Arbor, USA;

关键词: Somatotropin;    Pulsatility;    Starvation;    Ketosis;   

DOI  :  10.1186/s40842-022-00137-y

来源: Springer

【 摘 要 】

BackgroundThe increase in growth hormone (GH) secretion during a prolonged fast stimulates lipolytic rate, thereby augmenting the mobilization of endogenous energy at a time when fuel availability is very low.Study aimTo identify the specific component of GH secretory pattern responsible for the stimulation of lipolytic rate during fasting in humans.Study protocolWe measured lipolytic rate (using stable isotope dilution technique) after an overnight fast in 15 young, healthy, non-obese subjects (11 men and 4 women), and again on four separate occasions after a 59 h fast. These four prolonged fasting trials differed only by the contents of an infusion solution provided throughout the 59 h fasting period. Subjects were infused either with normal saline (“Control”; n = 15) or with graded doses of a GH Releasing Hormone Receptor Antagonist (GHRHa):10 μg/kg/h (“High”; n = 15), 1 μg /kg/h (“Medium”; n = 8), or 0.5 μg /kg/h (“Low”; n = 6).ResultsAs expected, the 59 h fast completely suppressed plasma insulin levels and markedly increased endogenous GH concentrations (12 h vs 59 h Fast; p = 0.0044). Administration of GHRHa induced dose-dependent reduction in GH concentrations in response to the 59 h fast (p < 0.05). We found a strong correlation between the rate of lipolysis and GH mean peak amplitude (R = 0.471; p = 0.0019), and total GH pulse area under the curve (AUC) (R = 0.49; p = 0.0015), but not the GH peak frequency (R = 0.044; p = 0.8) or interpulse GH concentrations (R = 0.25; p = 0.115).ConclusionDuring prolonged fasting (i.e., 2–3 days), when insulin secretion is abolished, the pulsatile component of GH secretion becomes a key metabolic regulator of the increase in lipolytic rate.

【 授权许可】

CC BY