During fasting, a lack of GH increases protein loss by close to 50%, but the underlying mechanisms remain uncertain. The present study tests the hypothesis that the anabolic actions of GH depend on mobilization of lipids. Seven normal... more
During fasting, a lack of GH increases protein loss by close to 50%, but the underlying mechanisms remain uncertain. The present study tests the hypothesis that the anabolic actions of GH depend on mobilization of lipids. Seven normal subjects were examined on four occasions during a 37-h fast with infusion of somatostatin, insulin, and glucagon for the final 15 h: 1) with GH replacement, 2) with GH replacement and antilipolysis with acipimox, 3) without GH and with antilipolysis, and 4) with GH replacement, antilipolysis, and infusion of intralipid. Urinary urea excretion, serum urea concentrations, and muscle protein breakdown (assessed by labeled phenylalanine) increased by almost 50% during fasting with suppression of lipolysis. Addition of GH during fasting with antilipolysis did not influence indexes of protein degradation, whereas restoration of high FFA levels regenerated proportionally low concentrations of urea and decreased whole body protein degradation (phenylalanine to...
Research Interests:
Research Interests: Endocrinology, Biology, Medicine, Molecular endocrinology, Biological Sciences, and 15 moreGrowth Hormone, Humans, Internal Medicine, Human Growth Hormone, Clinical, Lipolysis, Male, Feedback, Mechanism, Clinical Sciences, Adult, Free Fatty Acid, Biochemistry and cell biology, Infusion Pumps, and Medical and Health Sciences
Research Interests: Metabolism, Insulin Resistance, Growth Hormone, Humans, Human Growth Hormone, and 11 moreGlucose, Diabetes mellitus, Proteins, Lipid metabolism, Clinical Sciences, Protein Metabolism, Acromegaly, Human Subjects, Hormone Replacement Therapy, Biochemistry and cell biology, and Paediatrics and reproductive medicine
Results: DHEA treatment normalized the levels of all androgens. Basal and insulin-stimulated total energy expenditure and rates of protein, lipid and glucose oxidation were unaffected by DHEA. Whole body turnover of glucose and protein... more
Results: DHEA treatment normalized the levels of all androgens. Basal and insulin-stimulated total energy expenditure and rates of protein, lipid and glucose oxidation were unaffected by DHEA. Whole body turnover of glucose and protein were also unaffected by DHEA. ...
Research Interests: Adipose tissue, Humans, Testosterone, Blood Glucose, Insulin, and 15 moreFemale, Proteins, Lipid metabolism, Clinical Sciences, European, Middle Aged, Protein Metabolism, Adrenal Insufficiency, Adult, Isotope Dilution, Dehydroepiandrosterone, Androstenedione, hydrocortisone, Indirect calorimetry, and Paediatrics and reproductive medicine
Objective: The regulation and function of systemic ghrelin levels appear to be associated with food intake and energy balance rather than GH. Since GH, in turn, acutely induces lipolysis and insulin resistance in skeletal muscle, we aimed... more
Objective: The regulation and function of systemic ghrelin levels appear to be associated with food intake and energy balance rather than GH. Since GH, in turn, acutely induces lipolysis and insulin resistance in skeletal muscle, we aimed to study the isolated and combined effects of GH, free fatty acids (FFAs) and insulin sensitivity on circulating ghrelin levels in human subjects. Design: Seven GH-deficient patients (aged 37 ± 4 years (mean ± s.e.)) were studied on four occasions in a 2 × 2 factorial design with and without GH substitution and with and without administration of acipimox, which lowers FFA levels by inhibition of the hormone-sensitive lipase, in the basal state and during a hyperinsulinemic euglycemic clamp. Results: Serum FFA levels decreased with acipimox administration irrespective of GH status. The GH-induced reduction in insulin sensitivity was countered by acipimox. Fasting ghrelin levels decreased insignificantly during GH administration alone, but were reduc...