Location: Arkansas Children's Nutrition CenterTitle: Different responses to soy and estradiol in the reproductive system of prepubertal male rats and neonatal male pigs) Author
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract only
Publication Acceptance Date: 2/19/2014
Publication Date: 4/15/2014
Citation: Ronis, M.J., Hennings, L., Gomez-Acevedo, H., Badger, T.M. 2014. Different responses to soy and estradiol in the reproductive system of prepubertal male rats and neonatal male pigs [abstract]. The FASEB Journal. 28(1 Supplement):373.5. Interpretive Summary:
Technical Abstract: Concerns have been raised regarding the safety of soy infant formula based on phytochemical components such as genistein, structurally similar to estradiol (E2). To examine potential estrogenic actions on male development, we fed weanling male rats casein-based or soy protein isolate (SPI)-based diets (PND21-PND33) and neonatal male piglets cow's milk or soy infant formulas (PND2-PND21), or treated the animals with E2. E2 reduced testis and prostate weight and serum testosterone (P<0.05) in both species. Soy diet had no effects. In the piglet, E2 increased testis tubule area, Sertoli cell and germ cell number (P<0.05), and decreased expression of CYP19 and StAR mRNA. Soy increased germ cell number (P<0.05). The major effect of E2 is to change gene expression in reproductive tissues. E2 changed expression of 2645 genes in rat testis vs. 312 genes changed by SPI >1.5-fold. 74% of the SPI genes were common to E2. In contrast, 353 genes were changed by E2 and only 116 by feeding soy formula in piglet testis with only 34 genes (29%) in common. These data suggest that soy diets are not estrogenic in the male reproductive system but may interact with a small subset of estrogen-regulated genes in a species and developmental stage-specific manner.