(074) Association of Androgen Receptor Signaling in Human Corpus Cavernosum with Serum Testosterone Levels
Bibliographic record
Abstract
Abstract Introduction Testosterone (T) plays an important role in properly developing and maintaining male reproductive tissues. The normal serum testosterone levels can vary between 300 to 1000 ng/dL or 10.4 to 34.7 nmol/L. However, it is unclear whether androgen receptor signaling can vary based on serum T levels or the half-life of testosterone therapy. What remains unknown is whether there is a uniform serum T level above which androgen receptor signaling within the tissue remains similar (saturation hypothesis). Objective We first evaluated whether varying serum levels of T alter androgen receptor (AR) signaling in human penile tissue. Then, we evaluated and compared AR signaling in corpus cavernosum tissue of men treated with short-acting vs. long-acting testosterone. We hypothesized that we would find similar AR signaling in the penile tissue of both eugonadal and hypogonadal men as well as those men receiving short and long-acting testosterone. Methods We obtained human corpus cavernosum (hCC) tissue biopsies during penile surgery (for erectile dysfunction) from 14 men. We recorded their serum T levels on week prior to surgery before 10AM. We used western blot to evaluate adrenergic receptor (AR) and VEGF protein levels. Men without erectile dysfunction undergoing penile surgery for Peyronie's disease were used as controls. Results The median age of participants was 61 (IQR 12) and the median T level was 325ng/dL (IQR 201.45). The results of western blot showed expression of similar levels of VEGF in hCC samples from men with T >200ng/dL. However, men with serum T levels lower than 200 ng/dL had decreased expression of VEGF and AR. Conclusions This finding is significant because it demonstrates that serum testosterone beyond a certain threshold may have a minimal impact on erectile function. If a serum testosterone threshold is identified, this threshold could be a valuable target for future studies on the effects of testosterone on ED. It may alter the treatment threshold for men who have ED as their primary symptom of hypogonadism. This data also suggests the saturation value for penile androgen receptors. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Acerus Pharmaceuticals, Boston Scientific, Coloplast, Endo Pharmaceuticals, Empower Pharmacy, Nestle Health, Olympus, Hims, Inc
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".