Cell Secretion: A Study of Pancreas and Salivary Glands

Junqueira, L. C.; Hirsch, Gottwalt Christian

doi:10.1016/s0074-7696(08)62575-9

Cited by 63 publications

(6 citation statements)

References 95 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). The finding is in agreement with the view that small discharges of zymogen occur continuously even during prolonged starvation (5,7). By contrast, many of the exocrine cells of the guinea pigs killed 1 hour after feeding showed large accumulations of intracistemal granules in an endoplasmic reticulum characterized by distended cavities and little or no preferred orientation (Fig.…”

Section: Morphologysupporting

confidence: 91%

A Cytochemical Study on the Pancreas of the Guinea Pig

Siekevitz

Palade

1958

The Journal of Cell Biology

173

View full text Add to dashboard Cite

Microsomes were isolated from the pancreas of stsrved and fed guinea pigs. In the first case, the gland was removed from animals starved for 48 hours; in the second, the pancreas was excised I hour after the be~nnlng of a meal that ended a fast of 48 hours. These are referred to below as fed animals. In both cases the tissue was homogenized in 0.88 ~' sucrose and the microsomes obtained by centrifuging the mitochondrial supernatant at 105,000 g for 60 minutes.In starved animals the content of the endoplasmic reticulum of the exocrine cells and the content of the microsomes were found to be of low or moderate density. In fed guinea pigs the cavities of the reticulum frequently contained dense intradsternal granules and the microsomes were distinguished by a content of high density sometimes in the form of recognizable intracisternal granules.In starved animals, the microsomes were found to account for 5 to 20 per cent of the trypsin-activatable proteolytie activity and ribonuclease activity of the whole cell, whereas in fed animals they contained uniformly almost 30 per cent of these activities.In fed animals the dense, cohesive content of the microsomes (intradsternal granules) could be isolated by breaking up the microsomes with dilute (0.1 per cent) deoxycholate solutions and separating microsomal subfractions by differential centrifugation. The specific enzymatic activities of a heavy microsomal subfraction rich in intracisternal granules were almost equal to those of isolated purified zymogen granules. The ribonucleoprotein particles attached to the microsomal membranes could be isolated by the same technique and found also to exhibit some of the same enzymatic activities. Corresponding subfractions isolated from the mierosomes of starved animals were considerably less active.The relevance of these findings for the synthesis and intracellular transport of protein in the exocrine cell of the pancreas is discussed.

show abstract

Section: Morphologysupporting

confidence: 91%

A Cytochemical Study on the Pancreas of the Guinea Pig

Siekevitz

Palade

1958

The Journal of Cell Biology

173

View full text Add to dashboard Cite

show abstract

“…Three steps in the secretory process have been noted such as uptake of substrates for biosynthesis, synthesis of secretory products and extrusion of these products (JUNQUEIRA and HIRSCH, 1956). The extrusion process induced by exogenous CCK was potentiated in the FOY group as illustrated in Fig.…”

Section: Discussionmentioning

confidence: 88%

“…Secretion of secretory products depends on three main steps : ingestion of substrates for biosynthesis, synthesis of secretory products, and extrusion of these products (JUNQUEIRA and HIRSCH, 1956). JAMIESON and PALADE (1971) have shown that the extrusion process is not an immediate consequence of synthesis but is set in motion by stimulation of the secretory cell with a secretagogue.…”

mentioning

confidence: 99%

Secretory responses of hypertrophied rat pancreas induced by repeated oral administrations of a synthetic protease inhibitor.

Yonezawa

1983

Jpn.J.Physiol

View full text Add to dashboard Cite

A dose of -(4-guanidinobenzoyloxy)phenylacetate methanesulfonate; 100 mg/kg body weight] was administered orally once a day for 30 days to a group of rats (FOY group). To the control group of rats, 10 ml/kg body weight of distilled water (a solvent of FOY-305) was administered in the same way. The FOY-305 administration induced hypertrophy of the pancreas : the increase in wet weight of the pancreas was significantly higher than the increase in DNA content. The administration also induced hyperpyknia in the FOY group as shown by the increased concentration of constituents (amylase, trypsinogen, and chymotrypsinogen) in the pancreas.The secretory responses of the exocrine pancreas to stimulation with cholecystokinin (CCK) were examined in vivo. The secretory responses induced by lowered doses of CCK in the FOY group were slightly greater than those in the control group, but the differences were not statistically significant. On the other hand, the responses induced by higher doses of CCK were significantly greater than those in the control group. The secretory responses to stimulation with CCK or acetylcholine (ACh) were examined further in vitro using an isolated perfused pancreas. Protein output induced by lower doses of the secretagogues (146-730 pM CCK or 10 nM ACh) was similar in the control and the FOY groups, but the output induced by higher doses of the secretagogues (1,460 pM CCK or 30-100 nM ACh) in the FOY group was significantly larger than that in the control group.The present results provided evidence that the FOY-305-induced hypertrophy and hyperpyknia of the rat pancreas coincided with potentiation of secretory responses to higher doses of the secretagogues.

show abstract

“…Secretion has been defined as being a chain process in which the following three main steps may be observed: ingestion, synthesis, and extrusion (Janqueira & Hirsch, 1956). For exocrine secretion of the pancreas, the T. KANNO AND M. YAMAMOTO following assumptions have been made, although the experimental basis for these has not been fully established (see Case, 1973) : (1) the exocrine pancreas consists of two functional units: acinar cells which secrete digestive enzymes and zymogens; centro-acinar and terminal duct cells which are responsible for electrolyte secretion; (2) secretin acts only on terminal duct cells and centro-acinar cells to stimulate an isotonic secretion rich in bicarbonate; (3) cholecystokinin-pancreozymin (CCK-PZ) and acetylcholine (ACh) act on acinar cells to cause the extrusion of the contents of zymogen granules.…”

Section: Introductionmentioning

confidence: 99%

Differentiation between the calcium‐dependent effects of cholecystokinin‐pancreaozymin and the bicarbonate‐dependent effects of secretin in exocrine secretion of the rat pancreas.

Kanno¹,

Yamamoto²

1977

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Differentiation between the secretary effects of pure natural cholecystokinin-pancreozymin (COK-PZ) and those of synthetic secretin was studied in the isolated pancreas of the rat perfused with a standard solution containing both Ca2+ and HCO3-, a Oa2+-deficient solution, or a HC-G-deficient solution.2. Secretin induced a dose-dependent increase in the flow of pancreatic juice and a slight but definite increase in amylase output which was also dependent upon the dose of secretin.3. The increase in the flow of pancreatic juice, induced by continuous stimulation with secretin (5 Ivy dog m-u./ml.), was completely abolished during perfusion with a HCO3--deficient solution, but was only slightly suppressed during perfusion with a Ca2+-deficient solution.4. The increase in flow, induced by continuous stimulation with CCK-PZ (5 Ivy dog m-u./ml.), was partly affected by the deprivation of HCO3-, but was strongly inhibited by the deprivation of Ca2+. The CCK-PZ-induced amylase output was not affected by the deprivation of HOG-, but was significantly inhibited by the deprivation of Ca2+.5. The present results favour the view that CCK-PZ acts on the acinar cells to increase both amylase output and juice flow, whereas secretin acts on centro-acinar and terminal duct cells to increase mainly juice flow.

show abstract

Cell Secretion: A Study of Pancreas and Salivary Glands

Cited by 63 publications

References 95 publications

A Cytochemical Study on the Pancreas of the Guinea Pig

A Cytochemical Study on the Pancreas of the Guinea Pig

Secretory responses of hypertrophied rat pancreas induced by repeated oral administrations of a synthetic protease inhibitor.

Differentiation between the calcium‐dependent effects of cholecystokinin‐pancreaozymin and the bicarbonate‐dependent effects of secretin in exocrine secretion of the rat pancreas.

Contact Info

Product

Resources

About