Abstract
Embryonic rat pancreas anlagen have been grown in a chemically defined medium, subdivided biweekly and recultured for a total time of 10 weeks. The total mass increment during this time was in excess of 1000-fold. Samples were removed for light and electron microscope examination and for periodic measurement of enzymatic activity. Morphogenesis and cytodifferentiation occurred, peripheral outgrowth of epithelial buds was followed by the formation of interconnecting tubular structures and, eventually, by the appearance of distinctive acinar cells with zymogen granules. Mitotic figures became conspicuous at the periphery of explants within a day after each subdivision resulting in the formation of new tubular structures and acini. In general, the central area of the explants presented more mature acini with zymogen granules than was manifested at the periphery. The enzymatic activities of amylase, lipase, and chymotrypsin developed maximally during the first week of culture, reached a plateau level by the second week, and remained at a relatively constant level throughout the 10-week culture period.
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- Chen L. B., Buchanan J. M. Mitogenic activity of blood components. I. Thrombin and prothrombin. Proc Natl Acad Sci U S A. 1975 Jan;72(1):131–135. doi: 10.1073/pnas.72.1.131. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen A., Heller H., Kulka R. G. The effect of hydrocortisone on exportable enzyme accumulation in the differentiating chick pancreas. Dev Biol. 1972 Nov;29(3):293–306. doi: 10.1016/0012-1606(72)90069-3. [DOI] [PubMed] [Google Scholar]
- Fingerhut B., Ferzola R., Poock A., Marsh W. H. A rapid saccharogenic method for the determination of serum amylase. Clin Chem. 1965 Sep;11(9):862–868. [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marsh W. H., Fitzgerald P. J. Assay of nanogram levels of triglyceride lipase with a radioactive substrate. J Lipid Res. 1972 Mar;13(2):284–287. [PubMed] [Google Scholar]
- Marsh W. H., Fitzgerald P. J. Pancreas acinar cell differentiation. IV. Assay of nanogram levels of chymotrypsin by radioactively labeled synthetic substrate. Anal Biochem. 1971 Mar;40(1):72–79. doi: 10.1016/0003-2697(71)90083-2. [DOI] [PubMed] [Google Scholar]
- Parsa I., Marsh W. H., Fitzgerald P. J. Chemically defined medium for organ culture differentiation of rat pancreas anlage. Exp Cell Res. 1970 Jan;59(1):171–175. doi: 10.1016/0014-4827(70)90640-3. [DOI] [PubMed] [Google Scholar]
- REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ronzio R. A., Rutter W. J. Effects of a partially purified factor from chick embryos on macromolecular synthesis of embryonic pancreatic epithelia. Dev Biol. 1973 Feb;30(2):307–320. doi: 10.1016/0012-1606(73)90091-2. [DOI] [PubMed] [Google Scholar]
- Rutter W. J., Pictet R. L., Morris P. W. Toward molecular mechanisms of developmental processes. Annu Rev Biochem. 1973;42:601–646. doi: 10.1146/annurev.bi.42.070173.003125. [DOI] [PubMed] [Google Scholar]
- SABATINI D. D., BENSCH K., BARRNETT R. J. Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J Cell Biol. 1963 Apr;17:19–58. doi: 10.1083/jcb.17.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sefton B. M., Rubin H. Release from density dependent growth inhibition by proteolytic enzymes. Nature. 1970 Aug 22;227(5260):843–845. doi: 10.1038/227843a0. [DOI] [PubMed] [Google Scholar]
- Vischer T. L. Stimulation of mouse B lymphocytes by trypsin. J Immunol. 1974 Jul;113(1):58–62. [PubMed] [Google Scholar]
- WEISSMANN G., DINGLE J. Release of lysosomal protease by ultraviolet irradiation and inhibition by hydrocortisone. Exp Cell Res. 1961 Oct;25:207–210. doi: 10.1016/0014-4827(61)90328-7. [DOI] [PubMed] [Google Scholar]