the findings reported here together with the available evidence provide support for the hypothesis that grf and srif are secreted tonically from the hypothalamus into the hypophyseal portal blood , and that superimposed upon this steady state release is an additional 3- to 4-h rhythmic surge of each peptide , providing for integration of the ultradian rhythm of gh secretion , as observed in peripheral blood .
C0023610
grf
C0020663
hypothalamus