The present study has been conducted to evaluate the effect of neonatal passive immunization against inhibin α subunit on testicular mRNA expression level of IGF-1 gene during prepubertal and pubertal stage in male rats. Thirty male rats (weighted 21.5±1.32 g, aged 15 days) were randomly assigned into two equal groups; antiserum treated and control groups, received inhibin-α antiserum (100μl of physiological saline containing 1μg antiserum, i.p.) and physiological saline (100μl, i.p.) at the 15th and 18th days old. Five males from each group were sacrificed at the 23th, 30th and 50th days old. Testis samples were obtained for evaluation of mRNA expression level of IGF-1 gene using RT- PCR. Testis of 50d treated male rats showed higher expression level of IGF-1 gene compared with control, while 23d and 30d showed insignificant changes between studied groups. In conclusion, passive immunization against endogenous circulating inhibin during prepubertal age can perform potent role in testicular functional status and performance in the males after puberty.
