The plasma concentration of growth hormone fluctuates widely with pronounced peaks at intervals of a few hours and troughs of nearly vanishingly low concentrations in between. The pattern of secretion varies, and different patterns affect growth differently. Tall children usually have frequent growth hormone peaks of a high amplitude, whereas short, healthy children usually have fewer peaks of a lower amplitude. Male and female rats have different patterns, and a "masculine" pattern promotes growth more than a "feminine" pattern. If the same amount of growth hormone is administered in several pulses rather than continuously, the effect on growth is much greater.
Secretory pattern and regulatory mechanism of growth hormone in cattle
