In this report, the properties of eight cases of amylase-linked immunoglobulins were gel filtration using Sephadex G-200 superfine. The class of heavy chain of amylase-linked immunoglobulins was proved to be gamma in four cases and alpha in three cases by immunoelectrophoresis followed by amylase activity staining. In one of the cases, the precipitin line against light chain lambda could be visualized only after treatment with 0.1 M 2-mercaptoethanol. Then, the type of light chain was determined to be exclusively lambda irrespective of heavy chain classes. In two cases, the immunoglobulin complexes were partially dissociated into normal amylase and immunoglobulin G at pH 8.6, and completely dissociated at pH 9.0. In three cases, the complexes were completely dissociated at pH 8.6. The precipitin line of papain treated amylase-linked immunoglobulin G against anti-Fc was not. This fact suggests that the binding site of amylase-linked immunoglobulins G was located in the Fab portion of immunoglobulin molecule and that the complexes are specific antigen-antibody complexes. Treatment with Con-A Sepharose caused the dissociation of the amylase-immunoglobulin complexes. It is suggested that the changes in the conformation of amylase-linked immunoglobulin causes the dissociation of this immuno-complex. Thus, it is elucidated that the complexes of amylase and immunoglobulins are specific antigen-antibody complexes, and that these complexes must be recognized as one of the circulating autoantibodies in plasma, and must be clearly distinguished from the other unknown macromolecular amylase complexes.

Amylases↗

PubMed1977

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

1. Differentiation between the secretory effects of pure natural cholecystokinin-pancreozymin (CCK-PZ) and those of synthetic secretin was studied in the isolated pancreas of the rat perfused with a standard solution containing both Ca2+ and HCO2-, a Ca2+ deficient solution, or a HCO3-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 CHO3- 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 HCO3-, 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.

Amylases↗

PubMed1977

Stimulus-secretion coupling in pancreatic acinar cells: influences of external sodium and calcium on responses to cholecystokinin-pancreozymin and ionophore A23187.

1. The roles of Na and Ca ions in stimulus-secretion coupling were analysed in the isolated and perfused rat pancreas.2. Partial replacement of NaCl with LiCl produced a diminution in both amylase output and pancreatic juice flow which were induced by 5 m-u. CCK-PZ/ml., and almost normal responses were usually regained immediately after the reintroduction of a standard concentration of NaCl. Nearly total replacement of NaCl with LiCl caused an almost complete inhibition of the responses, although 25 mM-NaHCO(3) and 1 mM-NaH(2)PO(4) were still present, and only partial recovery was obtained after the re-introduction of a standard concentration of NaCl.3. A quantitative relationship was found between the amount of amylase released by CCK-PZ and the [Na(+)](o) over the range 26-157 mM in the presence of 2.5 mM-Ca. A similar relationship was also observed when [Ca(2+)](o) was decreased to 1.0 mM, but the responses were reduced to about one half of those observed with 2.5 mM-Ca.4. The most satisfactory theory which explains the cellular mechanism of CCK-PZ-induced amylase output, and which fits the experimental data, requires the dominant activity of a complex composed of a carrier molecule bearing one Ca and four Na molecules, if there is no interaction between Na(+) and Li(+).5. A quantitative relationship was also found between the amount of pancreatic juice flow stimulated by CCK-PZ and [Na(+)](o), over the range 26-157 mM, in the presence of 1.0 or 2.5 mM-Ca.6. A similar quantitative relationship was found between the amount of amylase released by Ca-ionophore A23187 and [Na(+)](o) in the presence of 2.5 or 5.0 mM-Ca. The most satisfactory theory which fits this experimental data also requires the dominant activity of a complex composed of a carrier molecule bearing one Ca and four Na molecules, if there is no interaction between Na(+) and Li(+).

Amylases↗

PubMed1977

Physiology of paraneurons.

An attempt is made in this review to elucidate the functional characteristics of paraneurons. The secretory functions of neuron, neurosecretory cell and paraneuron consist of three main phases: secretion, transmission and reversion. Secretion can be divided into a steady state and an activated state. A paraneuron behaves characteristically in the active phase of secretion and in the phase of transmission. There are three main events in the activated phase of secretion ("stimulus-extrusion coupling") in paraneurons, reception of stimulus, conduction of excitation, and extrusion of secretory substances. These three events seem to correspond to the functional characteristics in the three different regions of the paraneuron membrane. A stimulus-induced change in conformation in the input region of paraneurons may result in the inward movement of Na+ and Ca++. The inward movement of Na+ sometimes coincides with a graded depolarization which may occasionally generate all-or-nothing, short-duration action potential possibly in the intermediate region. A rise in [Ca++]i, whether it coincides with Na-dependent depolarization or not, may initiate extrusion of granules. If eccytosis is the mode of extrusion of secretory granules of paraneurons, the cell membranes at the output region should be rearranged by fusion with the membranes of granules. Ionic permeability of the output region might decrease during eccytosis if ionic permeability of the granule membrane is lower than that of other regions. Somatostatin in most cases and insulin in a special case may act locally on the adjacent target cells, and such a mode of transmission may come into the category of paracrine secretion.

Action Potentials↗

PubMed1977