Anion secretion by the isolated rabbit pancreas

Kuijpers, Gemma A.J.; Nooy, I.G.P. Van; Pont, J.J.H.H.M. de; Bonting, S.L.

doi:10.1016/0005-2736(84)90301-8

Cited by 18 publications

(4 citation statements)

References 17 publications

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“…However, we found that some fluid was secreted by the ducts even after all extracellular chloride had been replaced by the impermeant anion gluconate. Similar results have been obtained using in vitro preparations of the cat, rat and rabbit pancreas (cat" Case et al 1979;rat, Evans, 1986; rabbit, Rothman & Brooks, 1965;Kuijpers, Van Nooy, De Pont & Bonting, 1984a). This small, residual secretion which persists after chloride withdrawal may result from bicarbonate diffusing across the apical membrane of the duct cell via the channel, which we have recently shown to possess a small, but significant, permeability to this anion (PC1/PHCO3 0 0-2; Gray et al 1990b).…”

Section: Discussionsupporting

confidence: 76%

Characteristics of fluid secretion from isolated rat pancreatic ducts stimulated with secretin and bombesin.

Ashton¹,

Argent²,

Green³

1991

The Journal of Physiology

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SUMMARY1. Micropuncture techniques were used to study the cellular mechanisms of fluid secretion by interlobular ducts isolated from the pancreas of copper-deficient rats.2. Perifusing ducts with a calcium-free buffer containing 5 mM-EGTA reduced the volume of fluid secreted in the presence of 10 nM-bombesin by 62 %, whereas fluid secretion measured in the presence of 10 nM-secretin was reduced by only 26 %. 4. SITS (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid; mM), reduced fluid secretion measured in the presence of bombesin by 61 %, but had no effect on the response to secretin. 5. The K+ channel blockers, barium (3 mM) and tetraethylammonium (TEA; 10 mM), inhibited fluid secretion measured in the presence of both secretin and bombesin by between 52 and 66%.6. From these results, we conclude that secretin and bombesin may utilize different intracellular signalling pathways and, furthermore, may activate different anion secretory mechanisms within the pancreatic ductal epithelium. However, the effect of the potassium channel blockers is consistent with both peptides activating secretory mechanisms which are electrogenic, and which depend for their operation on potassium efflux across the basolateral membrane of the duct cell.

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Section: Discussionsupporting

confidence: 76%

Characteristics of fluid secretion from isolated rat pancreatic ducts stimulated with secretin and bombesin.

Ashton¹,

Argent²,

Green³

1991

The Journal of Physiology

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“…(but HC03output by only 20 %) during replacement of Clby isethionate (Kuijpers et al 1984a), while fluid secretion fiom isolated, secretin-stimulated rat pancreatic ducts is reduced by 70% during replacement of Clby gluconate (Ashton, Argent & Green, 1991). It is difficult to compare our studies on the isolated guineapig duct, in which HC03secretion was monitored over a few minutes, with those in the rat duct, where the secretion, a CF-rich fluid, was collected by micropuncture over a period of 1 h (Argent et al 1986).…”

Section: Measurement Of Luminal Ph and Coconcentration By Microfluoromentioning

confidence: 99%

“…(but HC03-output by only 20 %) during replacement of Clby isethionate (Kuijpers et al 1984a), while fluid secretion fiom isolated, secretin-stimulated rat pancreatic ducts is reduced by 70% during replacement of Cl-by gluconate (Ashton, Argent & Green, 1991 …”

Section: Hco3-/c02mentioning

confidence: 99%

Bicarbonate secretion in interlobular ducts from guinea‐pig pancreas.

Ishiguro

Steward

Wilson

et al. 1996

The Journal of Physiology

131

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Manchester M13 9PT, UK 1. The transport of HC03-across the luminal membrane of pancreatic duct cells was studied by monitoring the luminal pH of isolated guinea-pig interlobular ducts after microinjection of an extracellular fluoroprobe, the dextran conjugate of 2'7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF-dextran). Luminal Cl-concentration was also measured by microfluorometry following microinjection of the dextran conjugates of 6-methoxy-N-(4-aminoalkyl)quinolinium bromide (ABQ-dextran) and Cl-NERF (Cl-NERF-dextran).2. When HC03-/C02 was admitted to the bath, a transient acidification of the duct lumen was observed, followed by a marked alkalinization. The latter was abolished when the luminal CF-concentration was reduced to 25-35 mm by replacement with glucuronate and may, therefore, be attributed to Cl--HC03-exchange at the luminal membrane.3. Secretin, forskolin and acetylcholine stimulated HC03-secretion into the lumen even when the luminal Cl-concentration was reduced to approximately 7 mm. Furthermore, agonistevoked HC03-secretion was not inhibited by luminal glibenclamide, dihydro-4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (H2DIDS) or 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB). These observations are not easily reconciled with HC03-transport across the luminal membrane being mediated by Cl--HC03-exchange in parallel with a Clconductance.4. Agonist-stimulated HC03-secretion was blocked by omitting Nae from the bath but not by addition of N-methyl-N-isobutylamiloride (MIA) or bafilomycin A1. This supports our previous conclusion that HC03-entry into duct cells from the extracellular fluid requires Nae but is not dependent on Na+-H+ exchange or vacuolar-type H+-ATPase activity. 5. The three actions of secretin on guinea-pig pancreatic duct cells described in this and the accompanying paper -stimulation of a relatively Cl--insensitive luminal HC03-efflux pathway, stimulation of basolateral Nae-HC03-cotransport, and lack of effect on intracellular pH -require the current model of pancreatic HC03-secretion to be modified.

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“…79,96,97 Its localization at the apical membrane was deduced first from electrophysiologic data, 54 and subsequently confirmed by pH i measurements in microperfused ducts. 79,96,97 Its localization at the apical membrane was deduced first from electrophysiologic data, 54 and subsequently confirmed by pH i measurements in microperfused ducts.…”

Section: Anion Exchangersmentioning

confidence: 88%