REGULATION
OF GROWTH
HORMONE
SECRETION
PITUITARY
HYPOTHALAMUS
MANY TISSUES
METABOLIC
EFFECTS:
INCREASED LIPOLYSIS
AND
PROTEIN SYNTHESIS
DECREASED GLUCOSE USE
BONE AND CARTILAGE
SKELETAL
GROWTH
EFFECTS
FREE IGF�s
BOUND IGF�s
THERE
ARE 6 DISTINCT
IGF
BINDING PROTEINS
IGFBP(1-6)
. ONE OF THEM IS
THE EXTRACELLULAR PORTION
OF
THE GH RECEPTOR
LIVER AND FIBROBLASTS
IGF-1
AND IGF-2 SECRETION
SOMATOSTATIN / GHIH
+
+
-
+
+
-
TRANSPORT IN BLOOD
GROWTH HORMONE
-
�SOMATOMEDIN�
exercise
STRESS
preREM
Sleep
-
Arginine
BASAL
GH ~
10-10M
TOO
LOW TO MEASURE ACCURATELY
-
�SOMATOMEDIN�
GHRH
GROWTH
HORMONE
IS
SPECIES-SPECIFIC