Journal
ENDOCRINOLOGY
Volume 150, Issue 11, Pages 5106-5112Publisher
ENDOCRINE SOC
DOI: 10.1210/en.2009-0305
Keywords
-
Categories
Funding
- Japan Society for the Promotion of Science research fellowships for young scientists (JSPS Research Fellow)
Ask authors/readers for more resources
Estradiol (E2) and other sex steroids play essential roles in the modulation of synaptic plasticity and neuroprotection in the hippocampus. To clarify the mechanisms for these events, it is important to determine the respective role of circulating vs. locally produced sex steroids in the male hippocampus. Liquid chromatography-tandem mass spectrometry in combination with novel derivatization was employed to determine the concentration of sex steroids in adult male rat hippocampus. The hippocampal levels of 17 beta-E2, testosterone (T), and dihydrotestosterone (DHT) were 8.4, 16.9, and 6.6 nM, respectively, and these levels were significantly higher than circulating levels. The hippocampal estrone (E1) level was, in contrast, very low around 0.015 nM. After castration to deplete circulating high level T, hippocampal levels of T and DHT decreased considerably to 18 and 3%, respectively, whereas E2 level only slightly decreased to 83%. The strong reduction in hippocampal DHT resulting from castration implies that circulating T may be a main origin of DHT. In combination with results obtained from metabolism analysis of [H-3]steroids, we suggest that male hippocampal E2 synthesis pathway may be androstenedione -> T -> E2 or dehydroepiandrosterone -> androstenediol -> T -> E2 but not androstenedione -> E1 -> E2. (Endocrinology 150: 5106-5112, 2009)
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available