Effect of copper on the secretion of human growth hormone

The response of human growth hormone to the oral administration of 5.0 mg copper was studied in plasma from 12 normal adults. Blood samples were collected at 30 min intervals over a period of 240 min after two basal measurements taken at time = -30 and time = 0 min. Six subjects responded to the stimulus with increased growth hormone secretion, revealing a positive correlation with plasma copper levels. The other six subjects presented a similar rise in plasma copper levels but no increase in plasma growth hormone levels. These results suggest that acute, high blood copper levels can increase basal growth hormone secretion in normal individuals, presumably by acting on the hypothalamic center.