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. 1999 Jan;194(Pt 1):51–60. doi: 10.1046/j.1469-7580.1999.19410051.x

Morphometric studies of secretory granule formation in mouse pancreatic acinar cells. Dissecting the early structural changes following pilocarpine injection

ILAN HAMMEL 1 ,✉, OSNAT SHOR-HAZAN 1 , TORA ELDAR 1 , DINA AMIHAI 1 , SYLVIA LEW 1 ,2
PMCID: PMC1467893  PMID: 10227666

Abstract

Secretory granule formation in pancreatic acinar cells is known to involve massive membrane flow. In previous studies we have undertaken morphometry of the regranulation mechanism in these cells and in mast cells as a model for cellular membrane movement. In our current work, electron micrographs of pancreatic acinar cells from ICR mice were taken at several time points after extensive degranulation induced by pilocarpine injection in order to investigate the volume changes of rough endoplasmic reticulum (RER), nucleus, mitochondria and autophagosomes. At 2–4 h after stimulation, when the pancreatic cells demonstrated a complete loss of granules, this was accompanied by an increased proportion of autophagosomal activity. This change primarily reflected a greatly increased proportion of profiles retaining autophagic vacuoles containing recognisable cytoplasmic structures such as mitochondria, granule profiles and fragments of RER. The mitochondrial structures reached a significant maximal size 4 h following injection (before degranulation 0.178±0.028 μm3; at 4 h peak value, 0.535±0.109 μm3). Nucleus size showed an early volume increase approaching a maximum value 2 h following degranulation. The regranulation span was thus divided into 3 stages. The first was the membrane remodelling stage (0–2 h). During this period the volume of the RER and secretory granules was greatly decreased. At the intermediate stage (2–4 h) a significant increase of the synthesis zone was observed within the nucleus. The volume of the mitochondria was increasing. At the last step, the major finding was a significant granule accumulation in parallel with an active Golgi zone.

Keywords: Mitochondria, endoplasmic reticulum, autophagosomes, zymogen granule synthesis

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Selected References

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  1. Aughsteen A. A., Cope G. H. Changes in the size and number of secretion granules in the rat exocrine pancreas induced by feeding or stimulation in vitro. A morphometric study. Cell Tissue Res. 1987 Aug;249(2):427–436. doi: 10.1007/BF00215527. [DOI] [PubMed] [Google Scholar]
  2. Castle J. D., Cameron R. S., Arvan P., von Zastrow M., Rudnick G. Similarities and differences among neuroendocrine, exocrine, and endocytic vesicles. Ann N Y Acad Sci. 1987;493:448–460. doi: 10.1111/j.1749-6632.1987.tb27230.x. [DOI] [PubMed] [Google Scholar]
  3. Cope G. H. Exocrine glands and protein secretion: a stereological viewpoint. J Microsc. 1983 Aug;131(Pt 2):187–202. doi: 10.1111/j.1365-2818.1983.tb04245.x. [DOI] [PubMed] [Google Scholar]
  4. Dunn W. A., Jr Studies on the mechanisms of autophagy: formation of the autophagic vacuole. J Cell Biol. 1990 Jun;110(6):1923–1933. doi: 10.1083/jcb.110.6.1923. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Farquhar M. G., Palade G. E. The Golgi apparatus (complex)-(1954-1981)-from artifact to center stage. J Cell Biol. 1981 Dec;91(3 Pt 2):77s–103s. doi: 10.1083/jcb.91.3.77s. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Farquhar M. G. Progress in unraveling pathways of Golgi traffic. Annu Rev Cell Biol. 1985;1:447–488. doi: 10.1146/annurev.cb.01.110185.002311. [DOI] [PubMed] [Google Scholar]
  7. Geuze J. J., Kramer M. F. Function of coated membranes and multivesicular bodies during membrane regulation in stimulated exocrine pancreas cells. Cell Tissue Res. 1974;156(1):1–20. doi: 10.1007/BF00220098. [DOI] [PubMed] [Google Scholar]
  8. Gundersen H. J., Jensen E. B. Stereological estimation of the volume-weighted mean volume of arbitrary particles observed on random sections. J Microsc. 1985 May;138(Pt 2):127–142. doi: 10.1111/j.1365-2818.1985.tb02607.x. [DOI] [PubMed] [Google Scholar]
  9. Hammel I., Dvorak A. M., Fox P., Shimoni E., Galli S. J. Defective cytoplasmic granule formation.II. Differences in patterns of radiolabeling of secretory granules in beige versus normal mouse pancreatic acinar cells after [3H]glycine administration in vivo. Cell Tissue Res. 1998 Sep;293(3):445–452. doi: 10.1007/s004410051136. [DOI] [PubMed] [Google Scholar]
  10. Hammel I., Dvorak A. M., Galli S. J. Defective cytoplasmic granule formation. I. Abnormalities affecting tissue mast cells and pancreatic acinar cells of beige mice. Lab Invest. 1987 Mar;56(3):321–328. [PubMed] [Google Scholar]
  11. Hammel I., Dvorak A. M., Peters S. P., Schulman E. S., Dvorak H. F., Lichtenstein L. M., Galli S. J. Differences in the volume distributions of human lung mast cell granules and lipid bodies: evidence that the size of these organelles is regulated by distinct mechanisms. J Cell Biol. 1985 May;100(5):1488–1492. doi: 10.1083/jcb.100.5.1488. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hammel I., Lagunoff D., Krüger P. G. Recovery of rat mast cells after secretion: a morphometric study. Exp Cell Res. 1989 Oct;184(2):518–523. doi: 10.1016/0014-4827(89)90349-2. [DOI] [PubMed] [Google Scholar]
  13. Jamieson J. D., Palade G. E. Intracellular transport of secretory proteins in the pancreatic exocrine cell. II. Transport to condensing vacuoles and zymogen granules. J Cell Biol. 1967 Aug;34(2):597–615. doi: 10.1083/jcb.34.2.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Jena B. P., Gumkowski F. D., Konieczko E. M., von Mollard G. F., Jahn R., Jamieson J. D. Redistribution of a rab3-like GTP-binding protein from secretory granules to the Golgi complex in pancreatic acinar cells during regulated exocytosis. J Cell Biol. 1994 Jan;124(1-2):43–53. doi: 10.1083/jcb.124.1.43. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Kalina M., Robinovitch R. Exocytosis couples to endocytosis of ferritin in parotid acinar cells from isoprenalin stimulated rats. Cell Tissue Res. 1975 Nov 12;163(3):373–382. doi: 10.1007/BF00219471. [DOI] [PubMed] [Google Scholar]
  16. Leblond C. P. The life history of cells in renewing systems. Am J Anat. 1981 Feb;160(2):114–158. doi: 10.1002/aja.1001600202. [DOI] [PubMed] [Google Scholar]
  17. Lew S., Hammel I., Galli S. J. Cytoplasmic granule formation in mouse pancreatic acinar cells. Evidence for formation of immature granules (condensing vacuoles) by aggregation and fusion of progranules of unit size, and for reductions in membrane surface area and immature granule volume during granule maturation. Cell Tissue Res. 1994 Nov;278(2):327–336. doi: 10.1007/BF00414176. [DOI] [PubMed] [Google Scholar]
  18. Oliver C. Endocytic pathways at the lateral and basal cell surfaces of exocrine acinar cells. J Cell Biol. 1982 Oct;95(1):154–161. doi: 10.1083/jcb.95.1.154. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Pfeffer S. R., Rothman J. E. Biosynthetic protein transport and sorting by the endoplasmic reticulum and Golgi. Annu Rev Biochem. 1987;56:829–852. doi: 10.1146/annurev.bi.56.070187.004145. [DOI] [PubMed] [Google Scholar]
  20. Réz G., Csák J., Fellinger E., László L., Kovács A. L., Oliva O., Kovács J. Time course of vinblastine-induced autophagocytosis and changes in the endoplasmic reticulum in murine pancreatic acinar cells: a morphometric and biochemical study. Eur J Cell Biol. 1996 Dec;71(4):341–350. [PubMed] [Google Scholar]
  21. Schroeder F., Jefferson J. R., Kier A. B., Knittel J., Scallen T. J., Wood W. G., Hapala I. Membrane cholesterol dynamics: cholesterol domains and kinetic pools. Proc Soc Exp Biol Med. 1991 Mar;196(3):235–252. doi: 10.3181/00379727-196-43185. [DOI] [PubMed] [Google Scholar]
  22. Severs N. J., Robenek H. Detection of microdomains in biomembranes. An appraisal of recent developments in freeze-fracture cytochemistry. Biochim Biophys Acta. 1983 Aug 11;737(3-4):373–408. doi: 10.1016/0304-4157(83)90007-2. [DOI] [PubMed] [Google Scholar]
  23. Uchiyama Y., Saito K. A morphometric study of 24-hour variations in subcellular structures of the rat pancreatic acinar cell. Cell Tissue Res. 1982;226(3):609–620. doi: 10.1007/BF00214788. [DOI] [PubMed] [Google Scholar]
  24. Watari N., Baba N. Several findings on the fine structural alterations of the exocrine pancreas after the administration of some chemicals. J Electron Microsc (Tokyo) 1968;17(4):327–341. [PubMed] [Google Scholar]
  25. Weintraub H., Abramovici A., Amichai D., Eldar T., Ben-Dor L., Pentchev P. G., Hammel I. Morphometric studies of pancreatic acinar granule formation in NCTR-Balb/c mice. J Cell Sci. 1992 May;102(Pt 1):141–147. doi: 10.1242/jcs.102.1.141. [DOI] [PubMed] [Google Scholar]
  26. Williams A. M., Cope G. H. Membrane dynamics in the parotid acinar cell during regranulation: a stereological study following isoprenaline-induced secretion. Anat Rec. 1981 Mar;199(3):389–401. doi: 10.1002/ar.1091990308. [DOI] [PubMed] [Google Scholar]

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