Localization of the androgen-synthesizing enzymes, androgen receptor, and sex steroids in the vagina: possible implications for the treatment of postmenopausal sexual dysfunction.
INTRODUCTION
To better understand the mechanisms underlying the beneficial effects of the intravaginal administration of dehydroepiandrosterone (DHEA) observed in postmenopausal women on sexual dysfunction.


AIMS
To identify the distribution of the androgen-synthesizing enzymes as well as androgen receptor (AR) and measure steroid levels in the monkey vagina.


METHODS
The cynomolgus monkey (Macaca fascicularis), the closest model to the human, has been used to measure the expression levels of steroidogenic enzymes and androgen receptor by quantitative reverse transcription polymerase chain reaction (n=4), confirmed by immunohistochemistry, and immunofluorescence (n=3). DHEA and its androgenic metabolites were quantified by LC-MS/MS (n=4).


MAIN OUTCOME MEASURES
The presence of SRD5A1, SRD5A2, HSD17B3, AR as well as nerve fibers (PGP 9.5) was investigated, and steroid levels were measured.


RESULTS
AR is widely distributed within the vaginal epithelium and also in the lamina propria with a lower expression in the muscularis layer and blood vessel walls. Androgen-forming enzymes, on the other hand, are expressed in the vaginal stratified squamous epithelium at a relatively high level where they are uniformly distributed from the basal membrane up to the superficial keratinized cells. The enzymes are at a lower level in blood vessel walls and zona muscularis where nerve fibers are localized. DHEA and its androgen metabolites are present at biologically significant concentrations in the monkey vagina.


CONCLUSION
The enzymes responsible for androgen formation as well as AR are at the highest level in the superficial layer of the stratified epithelium and muscularis layers of the vagina. These data provide a potential explanation for the described role of androgens in regulating vaginal lubrication, smooth muscle activity, blood flow, and the neuronal activity potentially involved in the correction of sexual dysfunction.
['Bertin|Jonathan|J|', 'Dury|Alain Y|AY|', 'Ouellet|Johanne|J|', 'Pelletier|Georges|G|', 'Labrie|Fernand|F|']
D015067:17-Hydroxysteroid Dehydrogenases D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase D000728:Androgens D000818:Animals D003687:Dehydroepiandrosterone D005260:Female D008252:Macaca fascicularis D017698:Postmenopause D011944:Receptors, Androgen D012735:Sexual Dysfunction, Physiological D053719:Tandem Mass Spectrometry D014621:Vagina
Androgens Vagina Sexual Dysfunction DHEA Vulvovaginal Atrophy