Quantitative ultrastructural analysis in cardiac membrane physiology.
E. Page. Am J Physiol235 (5):
Quantitative measurements on electron micrographs of heart muscle
can yield information useful for cellular physiologists and at present
not obtainable in other ways. These methods are subject to preparative
artifact, sampling problems, and problems inherent in the mathematical
description of ultrastructure. Nevertheless they provide the best
available data for membrane areas of the plasmalemma and its components,
as well as for membrane areas of the sarcoplasmic reticulum and mitochondria.
Morphometric methods can be used to study growth of membranes. Changes
in the volumes of intracellular membrane-limited subcompartments
can also be measured. Quantitative analysis of freeze-fractured membrane
replicas can be carried out either by a statistical approach or by
optical diffraction. In this way, physiological perturbations or
developmental events leading to changes in membrane permeability
can be studied for correlated changes in membrane structure.