Desmosterol, the main sterol in rabbit semen： distribution among semen subfractions and its role in the in vitro spermatozoa acrosome reaction and motility

作     者：Evangelia Mourvaki Raffaella Cardinali Rita Roberti Alessandro Dal Bosco Cesare Castellini 

作者机构：Department of Applied Biology Section of Animal Science University of Perugia Perugia 06100 Italy Department of Internal Medicine Section of Biochemistry University of Perugia Perugia 06122 Italy 

出 版 物：《Asian Journal of Andrology》 (亚洲男性学杂志（英文版）)

年 卷 期：2010年第12卷第6期

页      面：862-870页

核心收录：

学科分类：1002[医学-临床医学] 0905[农学-畜牧学] 09[农学] 090501[农学-动物遗传育种与繁殖] 

主　　题：acrosome reaction cholesterol desmosterol motility prostatic secretory granules rabbit seminal plasma spermatozoa head spermatozoa tail 

摘      要：Sterols are essential components of the cell membrane lipid bilayer that include molecules such as cholesterol and desmosterol, which are significantly found in the spermatozoa of several animal species. However, the presence of desmosterol in rabbit semen has never been investigated. The aims of this study were to characterize the sterol composition of subfractions of ejaculated rabbit semen and evaluate the in vitro effects of sterol on the spermatozoa acrosome reaction and motility. Two sterols, occurring prevalently in the free form （94.3%）, were identified in whole semen collected from 10 fertile New Zealand White rabbits, specifically desmosterol （58.5% of total sterols） and cholesterol （35.9% of total sterols）. Desmosterol was the predominant sterol found in all subfractions of rabbit semen, varying from 56.7% （in the prostatic secretory granules, PSGs） to 63.8% （in the seminal plasma）. Spermatozoa contained an intermediate proportion of desmosterol （59.8%）, which was asymmetrically distributed between the heads （52.0% of the total content of sterols） and the tails （81.8%）. Results showed that both desmosterol and cholesterol can be transferred from the PSGs to the spermatozoa and are equally effective in inhibiting in vitro spermatozoa capacitation at a concentration higher than 1 mg L^-1. In contrast, neither desmosterol nor cholesterol had a significant effect on spermatozoa motility. Thus, it was concluded that, the various fractions of rabbit seminal fluid differ from each other in sterol composition and quantity, probably due to their different functional properties, and these fractions may undergo significant sterol changes depending on the stage of spermatozoa capacitation.