Use of taxol and collagenase for better three-dimensional visualization of microtubules in the enterocyte and Brunner's gland cell, with special reference to their relation to the Golgi apparatus.

Cytoskeletal microtubules were visualized in the mouse duodenal mucosa by an improved immunofluorescence method using a microtubule-stabilizing reagent, Taxol, and collagenase as an enzymatic epitope retriever. The improvement in immunostaining was shown morphologically and statistically by comparing fluorescence intensities of specimens prepared with or without Taxol and collagenase treatment. In free cells in the epithelium and in the lamina propria, microtubules radiated from the gamma-tubulin-immunostained organizing center. Enterocytes and Brunner's gland cells double-stained with an anti-alpha-tubulin antibody and a lectin (Helix pomatia agglutinin, soybean agglutinin or Ulex europaeus agglutinin-I) showed that microtubules ran along the cell axis and were abundant between the Golgi apparatus and the apical surface. The microtubules appeared to provide a structural support to hold the Golgi apparatus in position and to act as railways for secretory granules, which are transported towards the apical surface. In addition, gamma-tubulin-like immunoreactivity was associated with the Golgi apparatus in the enterocytes. These results show that the method using Taxol and collagenase is effective for visualizing microtubules in epithelial cells, and that microtubules may play important roles in both positioning of the Golgi apparatus and transport of secretory granules. Our results also support the idea that the Golgi apparatus may act as an organizing center for microtubules.