Effect of progestins on IGF-I serum level in estrogen-treated postmenopausal women.
Insulin-like growth factor I (IGF-I) has a role in the whole-body anabolism and promotes both normal and abnormal cell growth in several tissues. Although IGF-I is also synthesized locally at numerous other sites, the liver does constitute the major site of its synthesis, and circulating IGF-I is mainly of hepatic derivation. The production of IGF-I is stimulated by growth hormone (GH), the secretion of which is influenced by circulating IGF-I level through a negative feed-back mechanism. Oral estrogen treatment causes a significant decrease of the IGF-I serum level, probably through a hepatocellular effect due to the first hepatic passage. Treatment with transdermal estradiol (tdE2) at the currently used doses does not cause, on average, substantial variations in the IGF-I serum level. The addition of an androgenic progestin--with strong hepatocellular actions, opposite to those of estrogen--completely reverses the IGF-I decrease induced by oral estrogens, and even causes a trend to IGF-I increase when tdE2 is used. Conversely, the addition of a non androgenic progestin, like dydrogesterone, does not cause interference with the estrogen effect.
Campagnoli
C
C
Servizio di Ginecologia Endocrinologica, Ospedale Ginecologico Sant'Anna, Torino, Italy.
Biglia
N
N
Cantamessa
C
C
Di Sario
M M
MM
Lesca
L
L
D000279:Administration, Cutaneous; D000284:Administration, Oral; D002979:Climacteric / Q000097:blood / Q000187:drug effects*; D015914:Estrogen Replacement Therapy; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008875:Middle Aged; D045167:Progesterone Congeners / Q000008:administration & dosage* / Q000009:adverse effects; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism
D045167:Progesterone Congeners; D012738:Sex Hormone-Binding Globulin; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I