title: The application of deconvolution analysis to elucidate the pulsatile nature of growth hormone secretion using a variable half-life of growth hormone.
abstract: A deconvolution analysis model to calculate pituitary growth hormone (GH) secretion rate from measured serum GH concentration has been developed. This uses an iterative method of 'curve-stripping' based on an estimate of the half-life. The model has been applied to serum GH profiles and demonstrates that GH secretion occurs in discrete bursts with quiescent periods between secretory episodes, an 'on-off' phenomenon. The model can clearly dissect complicated concentration profiles such as the serum GH concentration response to growth hormone releasing hormone. The estimate was derived from calculating the half-life of serum GH in 10 subjects following an intravenous bolus injection of 50 mU of biosynthetic human growth hormone (b-hGH) and following infusions of the exogenous hormone (3 mU/kg/h) for 15, 30, 60 and 180 min. Endogenous GH secretion was suppressed by a continuous infusion of somatostatin (1-14). An asymptotic relationship between the duration of GH infusion and the GH half-life was established. A half-life of 15.3 min was achieved after exposure to GH for 60 min and a maximum half-life of 15.7 min after 180 min exposure.
authors.affiliation: Endocrine Unit, Middlesex Hospital, London, UK.
authors.forename: P C
authors.initials: PC
authors.lastname: Hindmarsh
authors.forename: D R
authors.initials: DR
authors.lastname: Matthews
authors.forename: C
authors.initials: C
authors.lastname: Brain
authors.forename: P J
authors.initials: PJ
authors.lastname: Pringle
authors.forename: C G
authors.initials: CG
authors.lastname: Brook
mesh_terms: D000293:Adolescent; D000328:Adult; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D006207:Half-Life; D006801:Humans; D008297:Male; D008954:Models, Biological
chemical_list: D013006:Growth Hormone