Ultrastructural aspects of the small intestinal lead toxicology.  Part II.  The small intestine goblet cells of rats during lead poisoning. 
The purpose of the present study was to evaluate the detoxification significance of the small intestinal goblet cells in rats on prolonged treatment with 0.01% lead acetate in the drinking water.  These goblet cells were analysed using a submicroscopic demonstration of heavy metals with the sulphide silver method and the X-ray microanalysis probe.  Male Wistar rats, weighing 80 g, were sacrificed after 2, 30 and 60 d of exposure to oral administration of lead.  The small intestines were perfused with Sörensen buffer with H2S, then blocks of tissue were removed from the border between the duodenum and jejunum and processed for transmission electron microscopy according to Grzybek (3) and Dancher (2).  At first the silver containing salt precipitates were distributed in the extracellular space between epithelial cells after 2 d of the experiment.  Treatment of rats with lead acetate for 30 d produced the characteristic appearance of the goblet cells at the electron microscopic level.  The presence of lead in conjunction with the goblet cell membrane has been observed.  If administration of lead to rats is continued longer than 30 d, in the mucus droplets located in the cytoplasm of goblet cells some deposits of silver salts may be demonstrated.  For the electron probe X-ray microanalysis the bulk specimens were prepared using a critical point drying apparatus.  The specimens were scanned along a line on the villous surface parallel to its long axis.  The X-ray studies indicated that accumulation of lead in the epithelial cells increased during the time of experiment.