Exploration of benign prostate hyperplasia in rats exposed by estradiol and testosterone with mathematics equation

OBJECTIVE To provide a new equation to explain the relationship between BPH and E2(estradiol) : T(testosterone) ratio.METHODS 176 male Sprague-Dawley rats(120 ±10) g were divided in 22 groups at random,including 20 groups of different E2 : T ratio,one control group and one castrated control group.The treated groups were administered(sc) daily with different dosages of T(4 doses of 0.3,0.85,2.5 and 7.5 mg /200 g) combined with different dosages of E2(0,2,6,17 and 50 g·kg-1) diluted in vegetable oil for 30 d,respectively,while the control groups received only olive oil.After the last treatment,all prostate specimens were removed under anesthesia and weighed,then fixed and embedded in paraffin.RESULTS Compared with control group,the prostate coefficient,E2,T and free T of treatment groups were rising obviously.The mathematics equation(P =-0.1782 + 0.0081 E2 + 0.063 T-0.6 × 10-5 E2 2-0.28 × 10-3 T2) and fitting figures were fitted by MATLAB soft,which expressed the relation between prostate coefficient(P) and T,E2.When serum T levels in rats were under(5.35 ±1.21) ng.ml-1 or above(142.64 ±27.23) ng.ml-1,the rat prostates proliferation were irrelevant to the serum E2 levels.Nevertheless,when T was between(5.35 ± 1.21)(142.64 ±27.23) ng.ml-1,the volumes of prostate were increasing with circulating E2 concentrations rising.CONCLUSION A new equation and simulation of the fitting figures were explored to explain the relationship between BPH and E2:T ratio,at the best comparation.