Phytoestrogens are plant-derived compounds with oestrogenic activity. They are common in both human and animal diets, particularly through soy-based foods. This study assessed whether the reproductive function of male rats is affected by exposure to a high phytoestrogen diet during adulthood and examined possible mechanisms through which phytoestrogens may disrupt reproductive function. Experiments focused on the epididymis, a steroid-regulated organ responsible for the maturation, transport, and storage of sperm.
Adult male rats, bred and raised on a low phytoestrogen diet, were either transferred to a high phytoestrogen diet (experimental), or remained on the low phytoestrogen diet (control). Litter size is a measure of fecundity and after 3 days on the high phytoestrogen diet litter size was reduced. This effect on fecundity was transient as litter sizes returned to control levels by day 12. The reduced fecundity at day 3 could not be explained by changes in sperm concentration. Plasma gonadotrophin levels and testicular testosterone levels were not affected by phytoestrogen exposure, however, the expression of steroid hormone receptors in the epididymis was affected, coincidental with reduced fecundity. The gene expression of oestrogen receptor alpha and androgen receptor was increased in the initial segment of the epididymis and decreased in the cauda epididymis. Additionally, lipid peroxidation of epididymal sperm was significantly increased in rats fed the high phytoestrogen diet for 3 days.
It is concluded that acute exposure to the high phytoestrogen diet disrupts the steroid regulation of the epididymis, disrupting its normal function. This results in decreased sperm quality, thereby reducing fecundity.
| Identifer | oai:union.ndltd.org:ADTP/217737 |
| Date | January 2006 |
| Creators | Glover, Amy, n/a |
| Publisher | University of Otago. Department of Anatomy & Structural Biology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://policy01.otago.ac.nz/policies/FMPro?-db=policies.fm&-format=viewpolicy.html&-lay=viewpolicy&-sortfield=Title&Type=Academic&-recid=33025&-find), Copyright Amy Glover |
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