Portal de Periódicos da CAPES

The Secretion Rate of Human Growth Hormone I. Daily Secretion Rates, Effect of Posture and Sleep

1973; Oxford University Press; Volume: 37; Issue: 4 Linguagem: Inglês

10.1210/jcem-37-4-515

1945-7197

F. P. Alford, H.W.G. Baker, Henry Burger,

Diet and metabolism studies

Immunoreactive GH secretion rates during daily activity, sleep and over 24-hr periods were calculated in 6 healthy men from integrated plasma GH concentrations obtained by a continuous blood sampling technique and metabolic clearance rates determined by the constant infusion of tracer doses of radioiodinated GH. The metabolic clearance rates determined by constant infusion of labeled (mean ± sem, 131 ± 7 1/day/m2) and unlabeled (140 1/day/m2) GH and those determined from the plasma disappearance curves of GH (134 ± 10 1/day/m2) were similar. The mechanism for clearance of GH from plasma was not saturable over a wide range of plasma concentrations of hormone. The metabolic clearance rate fell significantly (p < 0.001) by 17.4 ± 1.3% with change of posture: the clearance rate when recumbent was 131 ± 7, and when erect, 109 ± 7 1/day/m2. The mean secretion rate was 388 μg/day. It was approximately 3 times greater at night during sleep, (28.5 ± 2.5 μg/hr) than during the day, (10.0 ± 1.6 μg/hr).