Incorporation of [35S]sulfate in normal and neoplastic rat pancreatic acinar cells in relationship to cytodifferentiation.
The rates of [35S]sulfate incorporation in highly differentiated acinar cells from normal pancreas, moderately differentiated cells of nafenopin-induced transplantable pancreatic carcinoma, and poorly differentiated cells from azaserine-induced transplantable pancreatic carcinoma were examined in an attempt to determine if sulfation is a property of acinar cells with well-developed secretory granules. The cells were dissociated, pulsed with [35S]sulfate (specific activity, approximately 1000 Ci/mmol) for 10 and 60 min, and chased with medium containing 100 X excess of cold inorganic sulfate for 0, 15, 60, and 120 min. The cells were then processed for determining their pool size and light and electron microscopic autoradiography. No significant differences among their pool sizes were observed. However, the light microscopic autoradiograms revealed the [35S]sulfate incorporation as follows: azaserine-induced transplantable pancreatic carcinoma greater than nafenopin-induced transplantable pancreatic carcinoma greater than normal pancreas. Electron microscopic autoradiograms revealed similar trends. The grain densities (concentration of radiation) were highest in the Golgi regions immediately postpulse (0 min) and gradually shifted toward the secretory granules over a 120-min period. In addition, the grain density values of the secretory granule-rich cells of nafenopin-induced transplantable pancreatic carcinoma were relatively similar to the cells of normal pancreas, whereas the grain density values of secretory granule-deficient cells from this tumor were similar to those of poorly differentiated neoplastic cells of azaserine-induced transplantable pancreatic carcinoma. These results show that poorly differentiated neoplastic cells incorporate more [35S]sulfate than do the well-differentiated cells, but the reasons for this unexpected differential incorporation are at present unknown.
D000818:Animals; D001345:Autoradiography; D002454:Cell Differentiation; D007700:Kinetics; D008297:Male; D008854:Microscopy, Electron; D010179:Pancreas / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D013431:Sulfates / Q000378:metabolism*; D013462:Sulfur Radioisotopes
D013431:Sulfates; D013462:Sulfur Radioisotopes