Abstract
The origin, morphogenesis, and biochemical differentiation of the dorsal and ventral pancreas of the rat embryo have been investigated in order to ascertain the similarities and dissimilarities between the two lobes. We have utilized a culture system in which the primitive gut gives rise to a number of differentiated organs, including the dorsal and ventral pancreas. The two pancreases do not undergo fusion in these cultures, thus allowing independent analyses of the two lobes for comparison with in vivo results. The dorsal pancreas first appeared at the 23–25 somite stage while the ventral pancreas appeared approximately 12 hr later at the 29–30 somite stage. Guts from embryos as young as 12 somites were capable of developing both pancreases in vitro. In spite of the 12 hr difference between the times of their appearance, the dorsal and ventral pancreases exhibited identical patterns of morphological and biochemical differentiation. The two lobes contained the same exocrine enzymes and hormones, at similar levels, differing only in their glucagon content, the dorsal pancreas possessing a fivefold higher glucagon specific activity. The implications of these results are discussed.
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Selected References
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- BEARD J. R., RAZZELL W. E. PURIFICATION OF ALKALINE RIBONUCLEASE II FROM MITOCHONDRIAL AND SOLUBLE FRACTIONS OF LIVER. J Biol Chem. 1964 Dec;239:4186–4193. [PubMed] [Google Scholar]
- FOLK J. E., SCHIRMER E. W. THE PORCINE PANCREATIC CARBOXYPEPTIDASE A SYSTEM. I. THREE FORMS OF THE ACTIVE ENZYME. J Biol Chem. 1963 Dec;238:3884–3894. [PubMed] [Google Scholar]
- GROBSTEIN C. CYTODIFFERENTIATION AND ITS CONTROLS. Science. 1964 Feb 14;143(3607):643–650. doi: 10.1126/science.143.3607.643. [DOI] [PubMed] [Google Scholar]
- Hazzard W. R., Crockford P. M., Buchanan K. D., Vance J. E., Chen R., Williams R. H. A double antibody immunoassay for glucagon. Diabetes. 1968 Apr;17(4):179–186. doi: 10.2337/diab.17.4.179. [DOI] [PubMed] [Google Scholar]
- KALLMAN F., GROBSTEIN C. FINE STRUCTURE OF DIFFERENTIATING MOUSE PANCREATIC EXOCRINE CELLS IN TRANSFILTER CULTURE. J Cell Biol. 1964 Mar;20:399–413. doi: 10.1083/jcb.20.3.399. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RUTTER W. J., WESSELLS N. K., GROBSTEIN C. CONTROL OF SPECIFIC SYNTHESIS IN THE DEVELOPING PANCREAS. Natl Cancer Inst Monogr. 1964 Apr;13:51–65. [PubMed] [Google Scholar]
- Rutter W. J., Kemp J. D., Bradshaw W. S., Clark W. R., Ronzio R. A., Sanders T. G. Regulation of specific protein synthesis in cytodifferentiation. J Cell Physiol. 1968 Oct;72(2 Suppl):1–18. doi: 10.1002/jcp.1040720403. [DOI] [PubMed] [Google Scholar]
- SMITH L. F. ISOLATION OF INSULIN FROM PANCREATIC EXTRACTS USING CARBOXYMETHYL AND DIETHYLAMINOETHYL CELLULOSES. Biochim Biophys Acta. 1964 Feb 10;82:231–236. doi: 10.1016/0304-4165(64)90293-4. [DOI] [PubMed] [Google Scholar]
- VENABLE J. H., COGGESHALL R. A SIMPLIFIED LEAD CITRATE STAIN FOR USE IN ELECTRON MICROSCOPY. J Cell Biol. 1965 May;25:407–408. doi: 10.1083/jcb.25.2.407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WOLFF E. C., SCHIRMER E. W., FOLK J. E. The kinetics of carboxypeptidase B activity. J Biol Chem. 1962 Oct;237:3094–3099. [PubMed] [Google Scholar]