Comparison of the growth-promoting effects of testosterone and 7-alpha-methyl-19-nor-testosterone (MENT) on the prostate and levator ani muscle of LPB-tag transgenic mice

Prostate. 2006 Mar 1;66(4):369-76. doi: 10.1002/pros.20354.


Background: 7-alpha-methyl-19-nortestosterone (MENT) is being considered for androgen replacement in testosterone deficient men and as a male contraceptive. Because androgenic effects on the prostate are a major concern, we have evaluated MENT in a transgenic model of prostate cancer.

Methods: LPB-Tag mice were castrated and infused with testosterone (T; 5 or 30 microg/day) or MENT (5 or 30 microg/day) for 4 weeks. Prostate, seminal vesicle, and levator ani muscle (LAM) weights were compared.

Results: At an equivalent dose, MENT maintained or stimulated the mean weights of these organs more than T. However, the dorsolateral prostate/LAM ratio of weights did not favor MENT, but DNA/mg tissue and Ki 67 immunostaining suggested that MENT may increase DNA less than T.

Conclusions: MENT is more potent than T in maintaining or stimulating prostate, seminal vesicle, and LAM. Using doses that resulted in comparable stimulation of the levator ani muscle, MENT had similar effect on prostate weight, but increased DNA/mg prostate less than T in this transgenic mouse model of prostate cancer.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Contraceptive Agents, Male / pharmacology
  • DNA / biosynthesis
  • Estrenes / pharmacology*
  • Female
  • Hormone Replacement Therapy
  • Male
  • Mice
  • Mice, Transgenic
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / growth & development
  • Prostatic Neoplasms / pathology*
  • Testis / drug effects*
  • Testis / growth & development
  • Testosterone / deficiency
  • Testosterone / physiology*


  • Contraceptive Agents, Male
  • Estrenes
  • Testosterone
  • methylestrenolone
  • DNA