Role of cytochrome p450 in synaptocrinology: endogenous estrogen synthesis in the brain hippocampus.

Content Provider	Semantic Scholar
Author	Murakami, Gen Tanabe, Nobuaki Ishii, Hiro-Taka Ogiue-Ikeda, Mari Tsurugizawa, Tomokazu Mukai, Hideo Hojo, Yasushi Takata, Norio Furukawa, Aizo Kimoto, Tetsuya Kawato, S.
Copyright Year	2006
Abstract	In the hippocampus, the center for learning and memory, cytochrome P450s (P450scc, P450(17alpha), and P450arom) as well as 17beta-, 3beta-hydroxysteroid dehydrogenases, and 5alpha-reductase participate in the synthesis of brain steroids from endogenous cholesterol. These brain steroids include pregnenolone, dehydroepiandrosterone, testosterone, dihydrotestosterone, and 17beta-estradiol. Both estrogens and androgens are synthesized in the adult male hippocampal neurons. Although the expression levels of steroidogenic enzymes are as low as 1/200 to 1/50,000 of those in testis or ovary, the levels of synthesized steroids are sufficient for the local usage within small neurons (i.e., intracrine system). This intracrine system contrasts with the endocrine system in which high expression levels of steroidogenic enzymes are necessary in endocrine organs in order to supply steroids to many other organs via blood circulation. Endogenous synthesis of sex steroids in the hypothalamus is also discussed. Rapid modulation by estrogens and xenoestrogens is discussed concerning synaptic plasticity such as the long-term potentiation, the long-term depression, or spinogenesis. Synaptic expression of P450(17alpha), P450arom, and estrogen receptors suggests "synaptocrine" mechanisms of brain steroids, which are synthesized at synapses and act as synaptic modulators.
Starting Page	8
Ending Page	11
Page Count	4
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://kawato-glia.sakura.ne.jp/pdf/drugmetabo.pdf
PubMed reference number	16877257v1
Volume Number	38
Issue Number	3
Journal	Drug metabolism reviews
Language	English
Access Restriction	Open
Subject Keyword	17-Hydroxysteroid Dehydrogenase Deficiency Androgens Aromatase Blood Circulation Cholesterol Depressive disorder Dihydrotestosterone Endocrine Glands Endocrine system Estradiol Estrogen Receptors Estrogens Hydroxysteroid Dehydrogenases Hydroxysteroids Hypothalamic structure Long-Term Potentiation Neuronal Plasticity Organ Ovary Oxidoreductase Steroids Synapses Testosterone chemosensitization/potentiation dehydroepiandrosterone
Content Type	Text
Resource Type	Article