Androgenic/estrogenic balance in the male rat cerebral circulation: Metabolic enzymes and sex steroid receptors

Rayna J Gonzales, Saema Ansar, Sue P. Duckles, Diana N. Krause

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

Tissues from males can be regulated by a balance of androgenic and estrogenic effects because of local metabolism of testosterone and expression of relevant steroid hormone receptors. As a critical first step to understanding sex hormone influences in the cerebral circulation of males, we investigated the presence of enzymes that metabolize testosterone to active products and their respective receptors. We found that cerebral blood vessels from male rats express 5α-reductase type 2 and aromatase, enzymes responsible for conversion of testosterone into dihydrotestosterone (DHT) and 17β-estradiol, respectively. Protein levels of these enzymes, however, were not modulated by long-term in vivo hormone treatment. We also showed the presence of receptors for both androgens (AR) and estrogens (ER) from male cerebral vessels. Western blot analysis showed bands corresponding to the full-length AR (110 kDa) and ERα (66 kDa). Long-term in vivo treatment of orchiectomized rats with testosterone or DHT, but not estrogen, increased AR levels in cerebral vessels. In contrast, ERα protein levels were increased after in vivo treatment with estrogen but not testosterone. Fluorescent immunostaining revealed ERα, AR, and 5α-reductase type 2 in both the endothelial and smooth muscle layers of cerebral arteries, whereas aromatase staining was solely localized to the endothelium. Thus, cerebral vessels from males are target tissues for both androgens and estrogen. Furthermore, local metabolism of testosterone might balance opposing androgenic and estrogenic influences on cerebrovascular as well as brain function in males.

Original languageEnglish (US)
Pages (from-to)1841-1852
Number of pages12
JournalJournal of Cerebral Blood Flow and Metabolism
Volume27
Issue number11
DOIs
StatePublished - Nov 2007
Externally publishedYes

Fingerprint

Cerebrovascular Circulation
Steroid Receptors
Estrogens
Testosterone
Enzymes
Androgens
Aromatase
Dihydrotestosterone
Oxidoreductases
Hormones
Cerebral Arteries
Androgen Receptors
Gonadal Steroid Hormones
Estrogen Receptors
Endothelium
Smooth Muscle
Blood Vessels
Estradiol
Proteins
Western Blotting

Keywords

  • Androgen receptor
  • Cerebral circulation
  • Dihydrotestosterone
  • Testosterone

ASJC Scopus subject areas

  • Endocrinology
  • Neuroscience(all)
  • Endocrinology, Diabetes and Metabolism

Cite this

Androgenic/estrogenic balance in the male rat cerebral circulation : Metabolic enzymes and sex steroid receptors. / Gonzales, Rayna J; Ansar, Saema; Duckles, Sue P.; Krause, Diana N.

In: Journal of Cerebral Blood Flow and Metabolism, Vol. 27, No. 11, 11.2007, p. 1841-1852.

Research output: Contribution to journalArticle

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