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J J Geuze

Publications and source records attributed to J J Geuze.

33 records · Page 2Linked to original sources
PubMed1976

Synthesis and intracellular transport of proteins in the exocrine pancreas of the frog (Rana esculenta). II. An in vitro study of the transport process and the influence of temperature.

Frog pancreatic tissue was pulse-labelled in vitro with 3H-leucine and protein transport was studied in exocrine cells by electron microscope autoradiography. The proteins appeared to be synthesized in the RER and transported to the secretory granules along a similar route and with the same velocity as previously described under in vitro conditions. Evidence was obtained for the involvement of the vesicular and tubular elements at the periphery of the Golgi system in transferring protein from the RER to the Golgi cisternae. Kinetics of the release of newly synthesized proteins from the RER and their appearance in the condensing vacuoles are discussed and related to results reported from other tissues. The transport velocity in this poikilothermic system was studied in relation to the incubation temperature and compared with results reported from its mammalian counterpart. At temperatures between 20 and 30 degrees C intracellular protein transport occurs faster in the frog than in the Guinea pig pancreas. At higher temperature the transport process was severely disturbed in the frog.

Animals↗
PubMed1973

Cell membrane resorption in the rat exocrine pancreas cell after in vivo stimulation of the secretion, as studied by in vitro incubation with extracellular space markers.

Pancreatic secretion in the rat was stimulated in vivo by pilocarpine injection causing 90% of the storage granules to be discharged within 2 h. Incubation in vitro with [(14)C]sorbitol indicated that maximal ingestion of this extracellular space marker occurred 3 h after secretogogue injection. Morphological cell membrane measurements on cells with stimulated secretion revealed a simultaneous decrease in amount of membrane bordering the microvilli at the cell apex, lamellar processes, and infoldings present at the latero-basal face of these cells. In 3-h stimulated cells, having the average zymogen granule content characteristic for that phase of secretion, ferritin treatment in vitro showed that the infoldings and related fragmentation vesicles had ingested ferritin and could consequently be considered as being transport vehicles for redundant cell membrane. During stimulated secretion numerous vesicles and vacuoles appeared in the apical cytoplasm. Part of these structures were postulated to be related to the Golgi complex and were discussed in relation to secretory protein transport. Another part of these structures was assumed to have an endocytotic nature, although they never contained ferritin.

Animals↗