Quantitative studies of APUD cells in airways and gut in the guinea pig. A comparison of various histochemical stains and different fixatives

Serotonin-containing epithelial cells in rat duodenum. I. Quantitative morphometric study of the distribution density

Serotonin (5HT)-containing epithelial cells in rat duodenum were studied quantitatively by three-dimensional morphometric analysis. Longitudinal sections covering the whole length of rat duodenum were stained by either 5HT immunohistochemistry or by glyoxylic acid fluorescent histochemistry. Three-dimensional values for positive cell density, namely the number of 5HT cells per unit volume of the epithelium, were obtained by stereological morphometry with the aid of a computer-assisted image analyzer. This analytical method provides an absolute value for the distribution density of 5HT-containing cells regardless of thickness of sections, or which of the two histochemical procedures is used. The mean number of such cells per unit volume was higher in the crypts than in the villi but varied little along the duodenum. The density of 5HT cells in a given duodenal region, however, varied greatly among individual animals. The villi of the 10 to 16-mm segment from the pylorus were identified as having the smallest individual variation and therefore as being the most suitable for statistical evaluation in future pharmacohistochemical investigations.

Guinea pig lung cells. Method of isolation and partial purification, identification, ultrastructure, and cell count

Guinea pig lung cells (over 700 x 10(6) cells/lung) were obtained following gentle digestion of lung tissues with a solution of protease type VII (50 micrograms/ml). The viability of these cells was over 86% as estimated by the trypan blue exclusion technique. The cell suspensions were elutriated into eight fractions, which were characterized by selected staining techniques (Alcian blue, esterase, and Papanicolaou) and by electron microscopy. Differential cell counts were done to establish the percentages of each type of cells in the overall population. Electron microscopy analyses of the cell populations have allowed the identification of most of the various isolated cell types and showed that the cellular organelles and ultrastructures were well preserved. These cell populations will be used for characterizing lung immunologic, metabolic, and endocrine functions, as well as for studying cell interactions.