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ARS Home » Southeast Area » Little Rock, Arkansas » Microbiome and Metabolism Research Unit » Research » Publications at this Location » Publication #151447
Title: UTERINE GROWTH PARAMETERS AND STEROID RECEPTOR GENE EXPRESSION IN RATS ON SOY AND WHEY-BASED DIETS

Author
item SIMMEN, ROSALIA - UAMS
item EASON, RENEA - ACNC
item TILL, RENEE - ACNC
item RONIS, MARTIN - UAMS
item BADGER, THOMAS - 6251-10-00

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2003
Publication Date: 3/17/2003
Citation: SIMMEN, R.C., EASON, R.R., TILL, R., RONIS, M.J., BADGER, T.M. Uterine Growth Parameters and Steroid Receptor Gene Expression in Rats on Soy and Whey-based Diets. JOURNAL OF FEDERATION OF AMERICAN SOCIETIES FOR EXPERIMENTAL BIOLOGY. 2003. v. 17(5). p. A1162. Abstract No. 713.6.

Interpretive Summary: Soy and whey proteins constitute two major proteins present in infant milk formulas. Consumption of soy and whey is thought to confer decreased risk for adult onset of mammary and colon cancers, as demonstrated using rodent models. However, it is not known whether exposure to these proteins during the early stages of fetal and neonatal development has adverse effects on the development of other reproductive tissues such as the uterus. This study present results to indicate that dietary exposure to soy and whey proteins of female pups either in utero or during early feeding has no negative effects on normal uterine biology. Thus, concerns on the safety of dietary factors such as soy may have no scientific basis.

Technical Abstract: Consumption of soy and whey is thought to confer decreased risks for mammary, colon, and prostate cancers. It is unknown if these diets affect normal uterine biology. Here we examined the effects of these diets on uterine growth and gene expression. Female offspring of Sprague-Dawley rats fed casein (CAS) beginning at gestation day 4 were weaned to diets with soy protein isolate (SPI), whey protein hydrolysate (WPH), or CAS + genistein (GEN). Uteri were isolated after 10 days and relative gene expression for estrogen (ER)-' and -ß, androgen (AR), and total progesterone (PR-A/B) receptors were determined. Uteri from rats of all diets had respectively, no and constitutive expression of ER-ß and ß-actin genes. GEN-fed rat uteri tended to have decreased gene expression for AR and ER-', and increased expression of PTEN tumor suppressor, vs. rats fed CAS. SPI and WPH did not affect receptor gene expression. Uterine endometrium of rats fed CAS, SPI, or SPI with reduced isoflavones (SPI-) from gestation day 4 until weaning were also analyzed by morphometry and immunohistochemistry. No diet-dependent changes were noted in luminal epithelial thickness. Increased proliferation of luminal but not glandular epithelium, determined by the proliferation marker PCNA was observed in SPI(-) (p< 0.01) vs. CAS- or SPI (+)-fed animals. The limited effects of soy and whey diets on uterine growth and differentiation may have important implications to women's health (USDA-CRIS6251-5100-002-06S).