Berndtson William E
Department of Animal and Nutritional Sciences, University of New Hampshire, Durham, NH 03824, USA.
Anim Reprod Sci. 2008 Apr;105(1-2):5-22. doi: 10.1016/j.anireprosci.2007.11.011. Epub 2007 Nov 26.
Investigators may choose among a variety of different approaches for identifying and quantifying potential treatment effects on sperm production rates. Should a treatment actually alter sperm production, the likelihood that the response will be detected and declared statistically significant depends on several factors. These include the size of the treatment response, the inherent variability associated with the endpoint of interest among normal, untreated males, and the number of replicate animals per treatment group. This study was undertaken to characterize the relative power and sensitivity of several widely used methods for quantifying sperm production, for the purpose of identifying those that would be the most likely to enable detection of actual treatment effects. For this exercise, the typical inherent variability associated with several endpoints of testicular function in rats, rabbits and humans was established by a review of the published literature. Based on this typical variability and a components-of-variance approach, the relative number of replicates needed to provide experiments of equivalent power and sensitivity was determined. Consideration was also given to the likely nature of changes in the testis in response to adverse treatments. Based on all of this information, the methods for quantifying spermatogenesis that would be most likely to detect an actual treatment effect were determined to be as follows (from greatest to least powerful and sensitive): (1) quantification of round spermatids per Sertoli cell or per seminiferous tubular cross-section, (2) the determination of the number of spermatids or daily sperm production (DSP) per gram of testis or per testis via volume density approaches, (3) the determination of the number of elongated spermatids or DSP per gram or per testis via the testicular homogenate approach, and (4) the direct enumeration of degenerating germ cells.
研究人员可以在多种不同方法中进行选择，以识别和量化对精子生成率的潜在治疗效果。如果一种治疗确实改变了精子生成，那么检测到这种反应并宣布其具有统计学意义的可能性取决于几个因素。这些因素包括治疗反应的大小、正常未治疗男性中与感兴趣终点相关的固有变异性，以及每个治疗组的重复动物数量。本研究旨在描述几种广泛使用的量化精子生成方法的相对效能和敏感性，以便确定那些最有可能检测到实际治疗效果的方法。在本研究中，通过回顾已发表的文献，确定了大鼠、兔子和人类睾丸功能几个终点的典型固有变异性。基于这种典型变异性和方差成分法，确定了提供具有同等效能和敏感性的实验所需的相对重复数量。还考虑了睾丸对不良治疗反应的可能性质。基于所有这些信息，确定最有可能检测到实际治疗效果的量化精子发生的方法如下（从效能和敏感性最高到最低）：（1）每支持细胞或每生精小管横截面积的圆形精子细胞的量化，（2）通过体积密度法确定每克睾丸或每个睾丸的精子细胞数量或每日精子生成量（DSP），（3）通过睾丸匀浆法确定每克或每个睾丸的延长型精子细胞数量或DSP，以及（4）退化生殖细胞的直接计数。
