RESTORATION OF TESTICULAR TRANSFERRIN, INSULIN-LIKE GROWTH-FACTOR-I (IGF-1), AND SPERMATOGENESIS BY EXOGENOUSLY ADMINISTERED PURIFIED FSH AND TESTOSTERONE IN MEDICALLY HYPOPHYSECTOMIZED RATS
N. Itoh et al., RESTORATION OF TESTICULAR TRANSFERRIN, INSULIN-LIKE GROWTH-FACTOR-I (IGF-1), AND SPERMATOGENESIS BY EXOGENOUSLY ADMINISTERED PURIFIED FSH AND TESTOSTERONE IN MEDICALLY HYPOPHYSECTOMIZED RATS, Archives of andrology, 33(3), 1994, pp. 169-177
To investigate the relation between testicular transferrin and insulin
-like growth factor-1 (IGF-I) secreted by Sertoli cells and the differ
entiation of germ cells in the rat, testosterone and/or purified FSH w
as administered to rats medically hypophysectomized by an LH-RH agonis
t. Spermatogenesis was quantitatively analyzed and concentrations of i
ntratesticular transferrin and IGF-1 were measured by radioimmunoassay
s. The last step of spermatogenesis was quantitatively restored by com
bined administration of testosterone and purified FSH. intratesticular
IGF-1 concentrations were significantly increased by combined adminis
tration of testosterone and purified FSH. From these observations, it
is surmised that IGF-1 may have a stimulatory effect on the last step
of spermatogenesis.