Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1964 Mar;20(3):473-95.
doi: 10.1083/jcb.20.3.473.

PROTEIN SYNTHESIS, STORAGE, AND DISCHARGE IN THE PANCREATIC EXOCRINE CELL. AN AUTORADIOGRAPHIC STUDY

L G CARO, G E PALADE

PROTEIN SYNTHESIS, STORAGE, AND DISCHARGE IN THE PANCREATIC EXOCRINE CELL. AN AUTORADIOGRAPHIC STUDY

L G CARO et al. J Cell Biol. 1964 Mar.

Abstract

The synthesis, intracellular transport, storage, and discharge of secretory proteins in and from the pancreatic exocrine cell of the guinea pig were studied by light- and electron microscopical autoradiography using DL-leucine-4,5-H(3) as label. Control experiments were carried out to determine: (a) the length of the label pulse in the blood and tissue after intravenous injections of leucine-H(3); (b) the amount and nature of label lost during tissue fixation, dehydration, and embedding. The results indicate that leucine-H(3) can be used as a label for newly synthesized secretory proteins and as a tracer for their intracellular movements. The autoradiographic observations show that, at approximately 5 minutes after injection, the label is localized mostly in cell regions occupied by rough surfaced elements of the endoplasmic reticulum; at approximately 20 minutes, it appears in elements of the Golgi complex; and after 1 hour, in zymogen granules. The evidence conclusively shows that the zymogen granules are formed in the Golgi region by a progressive concentration of secretory products within large condensing vacuoles. The findings are compatible with an early transfer of label from the rough surfaced endoplasmic reticulum to the Golgi complex, and suggest the existence of two distinct steps in the transit of secretory proteins through the latter. The first is connected with small, smooth surfaced vesicles situated at the periphery of the complex, and the second with centrally located condensing vacuoles.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. J Cell Biol. 1962 Nov;15:189-99 - PubMed
    1. Biochim Biophys Acta. 1959 Oct;35:554-5 - PubMed
    1. J Biophys Biochem Cytol. 1958 May 25;4(3):309-18 - PubMed
    1. J Biophys Biochem Cytol. 1957 Mar 25;3(2):319-22 - PubMed
    1. J Biophys Biochem Cytol. 1961 Mar;9:539-53 - PubMed

MeSH terms