Maternal fructose intake disturbs ovarian estradiol synthesis in rats

Aims: Recent increases in fructose consumption have raised concerns regarding the potential adverse intergenerational effects, as maternal fructose intake may induce physiological dysfunction in offspring. However, no reports are available regarding the effect of excess maternal fructose on reproductive tissues such as the ovary. Notably, the maternal intrauterine environment has been demonstrated to affect ovarian development in the subsequent generation. Given the fructose is transferred to the fetus, excess fructose consumption may affect offspring ovarian development. As ovarian development and its function is maintained by 17β-estradiol, we therefore investigated whether excess maternal fructose intake influences offspring ovarian estradiol synthesis. Rats received a 20% fructose solution during gestation and lactation. After weaning, offspring ovaries were isolated. Key findings: Offspring from fructose-fed dams showed reduced StAR and P450(17α) mRNA levels, along with decreased protein expression levels. Conversely, attenuated P450arom protein level was found in the absence of mRNA expression alteration. Consistent with these phenomena, decreased circulating levels of estradiol were observed. Furthermore, estrogen receptor α (ERα) protein levels were also down-regulated. In accordance, the mRNA for progesterone receptor, a transcriptional target of ERα, was decreased. These results suggest that maternal fructose might alter ovarian physiology in the subsequent generation.