Surface area ratios. II. A stereological method for estimating changes in average cell volume and frequency.

The study describes a sterological method for detecting relative changes in cells--with respect to their average volumes and to their frequencies within one cm3 of exocrine cells. The method is based on surface area ratios (Bolender, '79) and can detect changes comparable to those obtained with the numerical density approaches (Loud, '68; Weibel et al., '69; Bolender, '74; Williams, '77). The new method requires only intersection counts--the same ones that are used for surface density estimates--and, as a result, avoids the difficult and often problematic procedures of the numerical densities. In analyzing the cellular changes in vitro, the choice of either a zero or timed control was found to exert a major influence on the results. Timed controls were required to "isolate" the experimentally induced changes from those produced by the incubation medium.