THEORY AND PRACTICE OF STEREOLOGICAL TECHNIQUES APPLIED TO THE ESTIMATION OF CELL NUMBER AND NUCLEAR VOLUME IN THE TESTIS

The historical background to contemporary approaches to the estimation of cell/nuclear number and volume in the testes is reviewed. The limi tations of older geometric model-based approaches to the estimation of cell/nuclear number are discussed, and the need for absolute estimate s of cell number rather than ratio estimates is examined. The physical and optical disector approaches to the direct estimation of numerical density and, hence, absolute cell number are presented together with data illustrating their operational efficiency in the testis. New appr oaches to the direct estimation of nuclear/cell volume, using the poin t-sampled intercept family of methods, are presented and illustrated, using the example of the Sertoli cell nucleus. The use of both classic al transverse and the newer vertical section approaches is explored. E stimation of Sertoli cell/nuclear volume in the volume (point-sampled intercept procedure) and number (nucleator and rotator methods) distri butions on both conventional transverse and vertical sections is discu ssed. The use of transverse sections of the testis is shown to produce a consistent bias in the estimation of Sertoli cell nuclear volume (m easured on vertical sections) in the volume and number-weighted distri bution suggests a coefficient of variation of volume in the number dis tribution of 0.4-0.5, suggesting either a random or stage-dependent va riation in Sertoli cell nuclear size which requires further exploratio n. (C) 1995 Wiley-Liss, Inc.