Singh V, Priyam M, Tripathy M, Rai U. Purification and identification of 25-hydroxycholesterol in a reptile: Seasonal variation and hormonal regulation.
Gen Comp Endocrinol 2017;
247:130-137. [PMID:
28126346 DOI:
10.1016/j.ygcen.2017.01.024]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 01/18/2017] [Accepted: 01/19/2017] [Indexed: 11/18/2022]
Abstract
The present in vitro study, for the first time, demonstrates the production of 25-hydroxycholestrol (25-HC) by testicular macrophages of a non-mammalian vertebrate. The ether extracts of testicular macrophage-conditioned medium (TMCM) were fractionated on a C18 reversed phase high-performance liquid chromatography (HPLC) column using methanol as the mobile phase. The mass spectrometry (MS) fragmentation pattern of HPLC-purified 25-HC was found to be identical to that of authentic 25-HC. Further, a significant seasonal variation in 25-HC concentration was observed with maximal level in regressed and minimal during breeding phase. To understand the hormonal control of 25-HC production, testicular macrophages from regressed phase testes were incubated with 0.5μg/ml of ovine follicle stimulating hormone (FSH) and 0.1, 1 and 10μg/ml of testosterone (T). FSH considerably enhanced 25-HC production by testicular macrophages. In contrast, T markedly inhibited 25-HC production in a dose-dependent manner. In addition, T significantly inhibited FSH-induced 25-HC production, though pre-treatment with T was more effective as compared to post-treatment with T to FSH. Our findings on production, seasonal variation and hormonal control of 25-HC suggest the functional significance of 25-HC in the testis of reptiles.
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