Dietary Exposure to Oxidized Frying Oil from Fetus to Adulthood Suppresses Male Reproductive Development by Altering Testicular Cholesterol and Testosterone Homeostasis in Sprague Dawley Rats

Abstract

Dietary frying oil may have endocrine-disrupting effects, as a feminization effect was observed in cohorts of C57BL/6J male mice fetuses from dams consuming oxidized frying oil (OFO) during pregnancy. The aim of present study was to test the hypothesis that OFO is an anti-androgen. In experiment 1, male progeny of Sprague Dawley female rats fed fresh oil or an OFO diet (10g fat/100g, from fresh or 24-h-fried soybean oil; [control diet (C) and OFO groups, respectively] from midgestation through lactation were studied. Pups were weaned at 3 wk of age and then consumed their mothers' diet until 9 wk of age. In addition, a group of dams and pups that consumed a high-fat diet (HF; 10g fried and 20g fresh soybean oil/100g) was included to counteract body-weight loss associated with OFO ingestion. Indices of male reproductive development and testosterone homeostasis were measured. In experiment 2, male rats were allocated to C and OFO groups (treated as above) and indices of male fertility compared at 9-10 wk of age. In experiment 1, final body weights of the HF group were lower (17%) than the C group but higher (14%) than the OFO group (P< 0.0001 for each). In addition to abnormalities in seminiferous tubules, HF and OFO groups did not differ from one another, but, compared with the C group, haddelayed preputial separation (4.9 d)andreductions inserum testosterone concentrations (17-74%), anogenital distance (8-20%),weights of androgen-dependent tissues (8-30%), testicular testosterone and cholesterol concentrations (30-40%), and mRNA levels of genes involved in steroidogenesis and cholesterol homeostasis (30-70%). In experiment 2, OFO-exposed males had 20% lower sperm motility (P< 0.05); however, when mated to normal females, pregnancy rates and litter sizes did not differ between OFO and C groups. The anti-androgenic effect of OFO in Sprague Dawley rats was attributed to decreased testicular concentrations of cholesterol (testosterone precursor) and notbody-weight loss.