Ontogenetic Profile of the Expression of Thyroid Hormone Receptors in Rat and Human Corpora Cavernosa of the Penis

Abstract

IntroductionIn the last few years, various studies have underlined a correlation between thyroid function and male sexual function, hypothesizing a direct action of thyroid hormones on the penis.AimTo study the spatiotemporal distribution of mRNA for the thyroid hormone nuclear receptors (TR) α1, α2 and β in the penis and smooth muscle cells (SMCs) of the corpora cavernosa of rats and humans during development.MethodsWe used several molecular biology techniques to study the TR expression in whole tissues or primary cultures from human and rodent penile tissues of different ages.Main Outcome MeasureWe measured our data by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) amplification, Northern blot and immunohistochemistry.ResultsWe found that TRα1 and TRα2 are both expressed in the penis and in SMCs during ontogenesis without development-dependent changes. However, in the rodent model, TRβ shows an increase from 3 to 6 days post natum (dpn) to 20 dpn, remaining high in adulthood. The same expression profile was observed in humans. While the expression of TRβ is strictly regulated by development, TRα1 is the principal isoform present in corpora cavernosa, suggesting its importance in SMC function. These results have been confirmed by immunohistochemistry localization in SMCs and endothelial cells of the corpora cavernosa.ConclusionsThe presence of TRs in the penis provides the biological basis for the direct action of thyroid hormones on this organ. Given this evidence, physicians would be advised to investigate sexual function in men with thyroid disorders. Carosa E, Di Sante S, Rossi S, Castri A, D'Adamo F, Gravina GL, Ronchi P, Kostrouch Z, Dolci S, Lenzi A, and Jannini EA. Ontogenetic profile of the expression of thyroid hormone receptors in rat and human corpora cavernosa of the penis. J Sex Med 2010;7:1381–1390.

Crossover of the Hypothalamic Pituitary–Adrenal/Interrenal, –Thyroid, and –Gonadal Axes in Testicular Development

“…(2, 6–12, 122)]. Recently, Flood et al (12) performed an in silico analysis of the promoter of several enzymes and receptors involved in both the androgen and TH axes.…”

Distribution of thyroid hormone and thyrotropin receptors in reproductive tissues of adult female rabbits

“…The presence of TRs and TSHR in the smooth musculature and corpus cavernosum of the clitoris, as well as in the glial cells of the dorsal nerve of the clitoris has not been previously approached in any species. In contrast, TRα and ß have been identified in the corpus cavernosum of the penis (46). Both hypo and hyperthyroidism are related to impotence in males by affecting the contraction of the corpus cavernosum and smooth muscle of the penis (47)(48).…”

The characterization, current medications, and promising therapeutics targets for premature ejaculation

“…The presence of thyroid hormone receptor isoforms in the male genital tract may be a further mechanism of action of that relationship. Carosa et al (2010) demonstrated the presence of TRa1, TRa2, and TRb in rat and human corpus cavernosum. TRa1 and TRa2 both expressed in the penis and smooth muscle cells during ontogenesis without-dependent changes TRb remained high in adulthood and its expression is regulated by development.…”