Stimulation of amylase secretion from the perfused cat pancreas by potassium and other alkali metal ions

Abstract

SUMMARY1. In the isolated cat pancreas, stimulated maximally with secretin, increasing the perfusate potassium concentration (at the expense of sodium ions) caused a copious secretion of amylase from the gland, reduced the volume rate of secretion and caused vasoconstriction.2. Rubidium and caesium had similar effects to potassium: lithium, though depressing secretary rate, had no effect on enzyme secretion or vasoconstrictor action.3. Amylase secretion was detected at potassium concentrations of 30 mm and was maximal at 80-90 mm, output declining as the concentration was raised to 120 mM.4. Amylase secretion was maximal during the first few minutes of exposure to excess potassium, but remained above basal levels throughout the test period. Secretory rate was depressed by a constant amount during the test period.5. Atropine sulphate blocked the effect on enzyme secretion without affecting the reduction in secretary rate.6. During perfusion with excess potassium a vasodepressor material with the properties of acetylcholine was detected in the effluent from the gland. 7. The reduction in secretary rate, when perfusate sodium was replaced by potassium, was equal to that obtained when sodium was replaced by sucrose.8. It is concluded that potassium stimulates amylase secretion indirectly * Part of this work was carried out during tenure of a Luccock Research Studentship, University of Newcastle upon Tyne. 612B. E. ARGENT, R. M. CASE AND T. SCRATCHERD by releasing acetylcholine from nerve terminals in the gland, and that the reduction in secretary rate is due not to excess potassium but to sodium deficiency.

Prostaglandin action on pancreatic blood flow and on electrolyte and enzyme secretion by exocrine pancreas in vivo and in vitro

“…The stimulatory effect of theophylline alone has previously been described . PGE1 and PGF1a (5 jug) were injected into the arterial supply of the perfused cat pancreas (at the times indicated by the arrows), preceded and followed by a small injection of acetylcholine chloride (ACh, 200 ng), the stimulatory effect of which has been described elsewhere (Argent et al 1971). Electrolyte secretion was stimulated maximally throughout by infusing pure (Mutt) secretin into the gland's arterial supply.…”

Potassium‐induced increase in oxygen consumption of brown adipose tissue from the rat.

“…The same electrophysiological set-up previously described (Girardier et al 1968) Argent, Case & Scratcherd (1971) suggesting an indirect action of KCl on many tissues. It was clearly shown in both of these studies that KCIinduced amylase secretion is in fact mediated by a release of acetylcholine in exocrine pancreas (Argent et al 1971) and by a release of catecholamines in salivary glands (Schramm, 1968). Similar studies remain to be done for nearly all other secretary glands as it is only in the adrenal medulla and in the nervous tissue that a direct KCl stimulation of secretion has been established.…”

Amylase secretion by the perfused cat pancreas in relation to the secretion of calcium and other electrolytes and as influenced by the extrenal ionic environment*

“…Effect of calcium and other cations on enzyme secretion. Potassium-rich fluids cause acetylcholine release from nerve terminals within the pancreas (Argent et al 1971). The present experiments suggest that potassium-free fluids act in a similar way.…”

“…Solutions containing potassium at concentrations greater than 30 mM/l. cause acetylcholine release from nerve terminals within the pancreas and thus secondarily cause amylase secretion (Argent, Case & Scratcherd, 1971). …”