Alzet pumps

To induce prostate regression (androgen-deprivation), male mice (8-weeks-old) were surgically castrated by standard technique. Mice were anesthetized with ketamine (100 mg/kg) and xylazine (10 mg/kg) and a 1 cm scrotal incision was made. Each testicle was individually pulled through the incision until the testicular fat pad was visualized. The vas deferens, testicular artery and veins were ligated with two silk ties and the testicle and epididymis were removed by transecting the structures with scissors in-between the ties. This was repeated for the contralateral testicle. The mice were observed for 4 weeks prior to any further interventions to allow complete regression of the prostate as previously described^{15 (link)}.
To induce prostate epithelial cell proliferation and prostate regeneration, testosterone-containing Alzet pumps (DURECT Corporation, USA) that continuously deliver testosterone (Sigma Aldrich, USA) at a rate of 1.875 μg/h to maintain physiologic serums levels of testosterone^{27 (link)} were subcutaneously inserted into male mice 4-weeks post castration or as indicated (Fig. 2a).

Eighteen recipient mice were randomly separated into 3 equal-sized groups: L-TMP group (TMP dissolved in 50% anhydrous ethanol, 25 mg/kg), H-TMP group (100 mg/kg), and CTL group (50% anhydrous ethanol, no TMP). After 3 weeks of infusion with SP, all recipient mice went through surgery to substitute the old, SP-containing Alzet pumps with new Alzet pumps (Model 2002, 0.5 μL/h, DURECT Corporation) containing different doses of TMP. Eighteen recipient mice were divided into 3 equal-sized groups at random: L-TMP group (TMP dissolved in 50% anhydrous ethanol, 25 mg/kg), H-TMP group (100 mg/kg), and CTL group (50% anhydrous ethanol, no TMP). Two weeks after the treatment, all mice were sacrificed by cervical dislocation and evaluated.