Preliminary investigation of the influence of long-term dietary isoflavone intake on reproductive tract histology and sex steroid receptor expression in female domestic cats (Felis catus)

Abstract

Preliminary investigation of the influence of long-term dietary isoflavone intake on 3reproductive tract histology and sex steroid receptor expression in female domestic 4 cats (Felis catus) 5 Summary 6Genistein and daidzein are isoflavones which are reported to influence the reproductive 7 system in a variety of mammalian species. This pilot study aimed to determine if dietary 8 isoflavones could potentially influence reproductive tract histology or morphology in 9 domestic cats, when consumed during the postnatal development period. Cats were 10 maintained on either treatment (150 μg/g DM genistein and 150 μg/g DM daidzein, n=4) 11 or control (isoflavone free, n=8) diets from weaning, up to 414 (± 17.2) days post-12 weaning. Reproductive tissues were collected during routine ovario-hysterectomy and 13 examined for histology and sex steroid receptor expression. Findings indicate that these 14 dietary isoflavones influenced the expression of oestrogen receptor α (ERα) and 15 oestrogen receptor β (ERβ), and progesterone receptor in feline reproductive tissues. One 16 cat in the treatment group developed suppurative endometritis, but no evidence of 17 uterotrophic or histological changes were found in any other cats. The potential to alter 18 expression of hormone receptors in the reproductive tract of domestic cats exposed to 19 genistein and daidzein warrants further investigation. 20