Avian neurosteroids. I. Pregnenolone biosynthesis in the quail brain

Kazuyoshi Tsutsui*, Yamazaki Takeshi Yamazaki

*この研究の対応する著者

研究成果: Article査読

137 被引用数 (Scopus)

抄録

The present study was carried out to determine steroid biosynthesis from cholesterol in the brain of adult male Japanese quails. As an initial step of the experiments, the concentrations of pregnenolone, dehydroepiandrosterone and their sulfate esters in the brain and plasma extracts were measured by specific radioimmunoassays (RIAs). To exclude the possibility that these steroids in the brain are derived from peripheral steroidogenic glands, hypophysectomized and sham-operated birds were used in this experiment. The pregnenolone concentration was much larger in the brain than in the plasma in these two groups. Hypophysectomy led to decreases in the plasma and brain pregnenolone concentrations, but the change in the brain was less pronounced than that in the plasma. Although pregnenolone sulfate ester, dehydroepiandrosterone and its sulfate ester were also detected in brain extracts, those levels were low in both hypophysectomized and sham-operated birds. The biochemical demonstration of cholesterol metabolism was further conducted in intact mitochondria. When mitochondrial fractions obtained from the whole brain were incubated with cholesterol at 37°C, the pregnenolone level in mitochondria increased as a function of incubation time. Finally, Western immunoblot analysis using a purified IgG with polyclonal antibodies against the purified bovine adrenal cytochrome P450scc was performed after SDS-gel electrophoresis of homogenates of the hypothalamus and preoptic area. A protein recognized the antibody as a band of electrophoretic mobility in the proximity of reference bovine P450scc. These results suggest that the brain produces pregnenolone from cholesterol in adult male Japanese quails. Most accumulation of pregnenolone in the brain may be independent of the peripheral endocrine gland system.

本文言語English
ページ(範囲)1-9
ページ数9
ジャーナルBrain Research
678
1-2
DOI
出版ステータスPublished - 1995 4 24
外部発表はい

ASJC Scopus subject areas

  • 発生生物学
  • 分子生物学
  • 臨床神経学
  • 神経科学(全般)

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