Effects of 17-P-Estradiol and Tamoxifen on the Stretch and Failure Load of the Medial Collateral Ligament of Prepubescent Female Rats

The purpose of this project was to test whether the effect of 17-fl-estradiol on the medial collateral ligament (MCL) would duplicate previous studies in which it increased laxity and if these effects would be mimicked by the use of a synthetic form of estrogen (tamoxifen) at pharmacological doses. My hypothesis was pharmacological levels of both 17-P-estradiol and tamoxifen would increase the laxity of the MCL without affecting the breaking point as compared to controls. Mechanical tests on the isolated MCL of prepubescent female rats were performed to test the stretch and breaking point weight after treatment with the equivalent of peak human levels of estradiol. Mechanical tests were also conducted on the isolated MCL of prepubescent rats treated with tamoxifen. Increased laxity in the MCL of the estradiol and tamoxifen treated rats, when compared with the control group, was observed. It was also determined increased levels of estradiol and tamoxifen did not affect the breaking point weight of the MCL