Testosterone and Estrogen Repletion in a Hypogonadal Environment Improves Post-operative Angiogenesis

To determine the effects of perioperative hormone supplementation on postoperative periurethral angiogenesis in the setting of hypogonadism, we analyzed the urethral tissue of castrated Sprague Dawley rats supplemented with testosterone or estrogen who underwent a urethral surgery and compared it to those that did not.

48 Sprague-Dawley rats were divided into 4 groups: (1) non-castrate (NC) controls; (2) castrate (C) unsupplemented rats; (3) castrate rats that received testosterone (T), or (4) castrate rats that received estradiol (E). Half of each group underwent urethroplasty surgery (S) while the other half were nonsurgical controls (C). With immunohistochemistry, we measured vessel density (endothelial cell marker CD31), expression levels of androgen receptor (AR), TIE-2, and estrogen receptor GPER1.

Periurethral vascularity was significantly increased postoperatively with both testosterone and estrogen supplementation (TC vs TS: 8.92% vs 10.80%, P<.001; EC vs ES: 7.66 vs 8.73%, P = .009) as well as in noncastrated rats (NCC vs NCS: 5.86% vs 8.19%, P<.001) whereas in the absence of hormones, CD31 expression significantly decreased after surgery (CC vs CS: 3.62% vs 2.76%, P= .003). CD31 expression was strongly correlated with AR, TIE-2, and GPER1 expression indicating a mechanistic relationship.

Both testosterone and estrogen supplementation increase periurethral vascularity in castrated (hypogonadal) rats undergoing urethroplasty surgery, contrary to decreased periurethral vascularity observed in the castrated non-supplemented rats. This suggests that hormonal resupplementation benefits post-operative regeneration in rats and may provide a basis for perioperative hormone supplementation in hypogonadal men prior to urethral surgery.