F. Gaytan et al., RESPONSE OF THE TESTIS TO GONADOTROPIN REPLACEMENT IN YOUNG HYPOPHYSECTOMIZED VS GONADOTROPIN-RELEASING-HORMONE ANTAGONIST-TREATED RATS, Andrologia, 29(2), 1997, pp. 85-90
We have studied the response of atrophic Leydig cells to gonadotrophin
replacement in young hypophysectomized (HX) and GnRH antagonist (GnRH
-ANT)-treated rats. Hypophysectomy was performed at 28 days of age. Ag
e-matched rats were treated with GnRH-ANT from 28 to 51 days of age. F
rom 45 to 51 days of age, animals were injected with 5 IU recFSH, 10 I
U hCG or vehicle. Body and testicular weights, as well as the diameter
of the seminiferous tubules were significantly higher in GnRH-ANT-tre
ated than in HX rats. Both recombinant FSH and hCG treatments induced
a similar increase in testicular weight and tubule diameter in HX and
GnRH-ANT-treated rats. However, hCG treatment induced a significantly
higher increase in Leydig cell size in HX (3.2-fold) than in GnRH-ANT-
treated (1.4-fold) rats. These results suggest that the response of at
rophic Leydig cells to gonadotrophin supplementation was partially inh
ibited in the presence of GnRH antagonist, whereas Sertoli cell-mediat
ed responses seem not to be affected.