The distribution of membrane bound enzymes in the acini and ducts of the cat pancreas

Wizemann, V.; Christian, Anna‐Luise; Wiechmann, Jutta; Schulz, Irene

doi:10.1007/bf00587053

Cited by 36 publications

(22 citation statements)

References 21 publications

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“…Our results and those of others (27,52) eliminate all of the enzymes studied as unique markers for ducts as opposed to other pancreatic components. An enzyme unique to the duct epithelium should have a specific activity in isolated ducts -50 x that in pancreatic homogenates, if one assumes that the duct epithelium contains 1% of the total pancreatic protein and that half of the isolated duct protein is found in the associated connective tissue .…”

supporting

confidence: 76%

“…The isolation from collagenase digests of duct cells from the rat (42) and ductule fragments from the rat (15) and mouse (20) has been reported in abstract form . Pancreatic ducts have been obtained by dissection from the rat (46), cat (52), and cow (27) and have been analyzed for their content ofvarious enzymes. The ultrastructural characteristics of the isolated bovine ducts have been defined (22).…”

mentioning

confidence: 99%

“…The ultrastructural characteristics of the isolated bovine ducts have been defined (22). However, in only one of these studies (52) were ducts smaller than the main pancreatic duct obtained. Another method for isolating pancreatic ducts is described in this paper.…”

mentioning

confidence: 99%

“…Previous studies of the enzymatic profiles of pancreatic ducts and acinar tissue have revealed larger specific activities of the following enzymes in the ducts : alkaline phosphatase (52), carbonic anhydrase (27), Mg-ATPase (52), HC0 3-ATPase (27,52), and 5'-nucleotidase (27,52) . Our results are in agreement with respect to the first four enzymes .…”

mentioning

confidence: 99%

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Characterization of ducts isolated from the pancreas of the rat.

Githens¹,

Holmquist²,

Whelan³

et al. 1980

The Journal of Cell Biology

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Rat pancreases were minced and treated with collagenase or collagenase supplemented with chymotrypsin to yield a mixture of ducts, islets, acinar cell clusters, blood vessels, and nerves . Histologically and ultrastructurally, the isolated tissues resembled their in situ counterparts in most respects, the major difference being the destruction of the basement membranes (basal laminae) . Ducts ranging in size from the common bile/main pancreatic duct to the intercalated ducts were identified in the digest, although interlobular ducts were most frequently observed .Acinar tissue fragments were separated from nonacinar structures either by flotation through discontinuous gradients of Ficoll or by sieving, the latter technique being the more efficient . Common bile/main ducts, interlobular ducts, and blood vessels were selected manually from the nonacinar fractions . Biochemical analyses showed that the entire nonacinar fraction, as well as isolated ducts and blood vessels, contained larger alkaline phosphatase, carbonic anhydrase, and Mg-ATPase specific activities than acinar tissue, whereas acinar tissue contained larger y-glutamyltranspeptidase and amylase activities . However, >63% of the total recovered activity of each enzyme was associated with the acinar tissue . Both the association of the majority of each of these enzyme activities with the acinar tissue and the similarity in specific activities associated with ducts and blood vessels indicate that none of the enzymes tested is a unique marker for interlobular and larger ducts of the pancreas of the rat.Pancreatic ducts comprise a simple cuboidal to columnar epithelium (12,16,21) and a layer of connective tissue . The ducts serve as a conduit for the movement of exocrine enzymes from the acinar cells to the duodenum and they also produce at least part of the secretin-stimulated bicarbonaterich pancreatic fluid secretion (9, 44) . The role of the ducts in fluid/electrolyte secretion has been supported by ultrastructural (24) and micropuncture (29, 43) studies and by studies of the relatively unimpaired fluid/electrolyte secretion in rats whose acinar cells have been destroyed (14) .Carbonic anhydrase in the dog (4), (Na+K)-ATPase in the rabbit (40, 48), and HC03-ATPase in the dog and cat (45) have been implicated in pancreatic fluid secretion by experiments in which specific inhibitors (acetazolamide, ouabain, and thiocyanate, respectively) reduced fluid secretion by the intact pancreas . Histochemical studies have demonstrated the presence in the duct epithelium J. CELL BIOLOGY C The Rockefeller University Press

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confidence: 76%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Characterization of ducts isolated from the pancreas of the rat.

Githens¹,

Holmquist²,

Whelan³

et al. 1980

The Journal of Cell Biology

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“…These results suggest that CCK-PZ acts on the acinar cell to produce the dual effects possibly via an activation of the Na pump,which is postulated to be in both basal and apical sides of the plasma membrane of acinar cell (KANNO,1974).If one assumes that the Na pump is identical with or very closely related to the Na+-K+-activated ATPase system,one would expect a higher activity of this system in those structures in which Na+-transport takes place.In fact, WIZEMANN et al(1974)have recently reported that,in the cat pancreas,the Na+-K+-activated ATPase activity is highest in the acinar structures although separation of centro-acinar cells from acinar cells was not possible.…”

Section: Discussionmentioning

confidence: 99%

Effects of Oxygen Supply on Electrical and Secretory Responses of Humorally Stimulated Acinar Cells in Isolated Rat Pancreas

1976

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A technique is described for perfusing isolated rat pancreas with a modified Krebs-Henseleit solution.This preparation made feasible the simultaneous measurement of transmembrane potential,effective membrane resistance,rate of flow of pancreatic juice and amylase output.The hyperpolarizing effect of cholecystokinin-pancreozymin(CCK-PZ)was confirmed by perfusion with a solution containing 5 mU CCK-PZ/ml.The hyperpolarizing effect of CCK-PZ was enhanced when the pancreas was perfused with an oxygenated solution containing dog erythrocytes.This effect was inhibited by ouabain and anaerobic conditions.It is suggested that the oxidative metabolism supplies energy for a mechanism which is responsible for the hyperpolarizing effect of CCK-PZ.The amylase output and the rate of flow of pancreatic juice were enhanced concurrently under conditions that augumented the hyperpo larizing effect,and they were inhibited under conditions that suppressed the effect.Cellular events in stimulus-secretion coupling in the pancreatic acinar cell are discussed by correlating the electrophysiological responses and the secretory responses under various conditions. A fresh clue to cellular events in the secretory process of the pancreatic acinar cell has recently been provided by the simultaneous measurement of transmembrane potential and amylase release.Thus it has been found that the addition of pancreozymin to the solution perfusing the pancreas induced a hyperpolarization of the acinar cells and increased amylase output (KANNO,1972(KANNO, ,1974.Further study revealed that the hyperpolarizing and secretory effects of pancreozymin concurrently disappeared with one of the following treatments ; low ambient temperature,K-free medium,low Na medium or application of ouabain (KANNO, 1975).Since these treatments are known to remove contribution of an electrogenic Na pump to the membrane potentials of nerve and muscle cells(see THOMAS,

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A review of in vitro andin vivo culture techniques for the study of pancreatic carcinogenesis

Jones¹,

Hudson²,

Resau³

1981

Cancer

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Techniques have been developed for long-term organ explant culture of bovine, hamster, and human pancreatic ducts in enriched medium. The explants were then exposed to chemical carcinogens and studied by morphologic and biochemical techniques. Untreated explants have also been successfully xenotransplanted into athymic "nude" mice. Techniques have also been developed to isolate human and bovine pancreatic ductal cells for cell culture. These as well as techniques developed by other authors are discussed.Cancer 47:1490-1496, 1981.ARCINOMA of the pancreas results in over 20,000C deaths per year in the United States and its incidence is i n~r e a s i n g .~~The goals of the National Pancreatic Cancer Project (NPaCP) are to reduce the incidence, morbidity, and mortality of pancreatic cancer. Objectives proposed by the Project to achieve these goals, which are relevant to this review, are:(1) Develop experimental models for investigation into etiology, prevention, detection, and treatment of cancer of the pancreas.

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The distribution of membrane bound enzymes in the acini and ducts of the cat pancreas

Cited by 36 publications

References 21 publications

Characterization of ducts isolated from the pancreas of the rat.

Characterization of ducts isolated from the pancreas of the rat.

Effects of Oxygen Supply on Electrical and Secretory Responses of Humorally Stimulated Acinar Cells in Isolated Rat Pancreas

A review of in vitro andin vivo culture techniques for the study of pancreatic carcinogenesis

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