Cyclic GMP Response in vivo to Cholinergic Stimulation of Gastric Mucosa

Nature ◽  
1974 ◽  
Vol 248 (5445) ◽  
pp. 238-239 ◽  
Author(s):  
JOHN H. EICHHORN ◽  
EDWIN W. SALZMAN ◽  
WILLIAM SILEN
Keyword(s):  
Gastric Mucosa ◽  
Cyclic Gmp ◽  
Cholinergic Stimulation ◽  
Stimulation Of

Possible role of cyclic GMP in stimulus-secretion coupling by salt gland of the duck

1979 ◽  
Vol 237 (5) ◽  
pp. C200-C204 ◽  
Author(s):  
D. J. Stewart ◽  
J. Sax ◽  
R. Funk ◽  
A. K. Sen
Keyword(s):  
Cyclic Amp ◽  
Guanylate Cyclase ◽  
Cyclic Gmp ◽  
Salt Gland ◽  
Domestic Ducks ◽  
Stimulus Secretion Coupling ◽  
Stimulation Of

Stimulation of salt galnd secretion in domestic ducks in vivo increased the cyclic GMP concentration of the tissue, but had no effect on cyclic AMP levels. Methacholine, which is known to stimulate sodium transport by the glands both in vivo and in vitro, stimulated ouabain-sensitive respiration in salt gland slices. Cyclic GMP stimulated ouabain-sensitive respiration to the same extent as methacholine. Guanylate cyclase stimulators, hydroxylamine and sodium azide, also stimulated ouabain-sensitive respiration. The stimulation of ouabain-sensitive respiration by methacholine was blocked either by atropine or by removal of calcium from the incubation medium. The stimulation of ouabain-sensitive respiration by cyclic GMP still occurred in the absence of calcium. The above observations seem to indicate that cyclic GMP acts as a tertiary link in the process of stimulus-secretion coupling in the tissue.

scholarly journals Breakdown of phosphatidylinositol provoked by muscarinic cholinergic stimulation of rat parotid-gland fragments

1974 ◽  
Vol 142 (3) ◽  
pp. 583-590 ◽  
Author(s):  
Lynne M. Jones ◽  
Robert H. Michell
Keyword(s):  
Lipid Metabolism ◽  
Cholinergic Stimulation ◽  
Muscarinic Cholinergic Receptors ◽  
The Past ◽  
Rat Parotid Gland ◽  
Muscarinic Cholinergic ◽  
High Concentrations ◽  
Rat Parotid ◽  
Stimulation Of

When rat parotid fragments that had been labelled with32P in vivo were exposed to high concentrations of acetylcholine, radioactivity was lost from phosphatidylinositol but not from other phospholipids. Simultaneously the concentration of phosphatidylinositol in the tissue decreased. If previously unlabelled tissue was incubated with32Pi an increase in incorporation of radioactivity into phosphatidylinositol was observed during this decrease in concentration. The effects of acetylcholine were blocked by atropine, but not by tubocurarine. The response to acetylcholine was rapid, with up to one-third of the tissue's phosphatidylinositol disappearing within 5min. Similar effects were evoked by stimulation with methacholine and by high concentrations of tetramethylammonium ion; these responses were also atropine-sensitive and tubocurarine-insensitive. It is concluded that the event in inositol lipid metabolism that is affected by acetylcholine stimulation is removal of the phosphorylinositol group from the molecule; this is mediated through muscarinic cholinergic receptors. This is followed by a compensatory increase in the rate of synthesis of phosphatidylinositol, which has been described in detail in the past. These observations are compared with those of previous workers and are discussed in relation to the existing hypotheses relating to the significance of stimulus-provoked phosphatidylinositol turnover.

Cholinergic stimulation of polyphosphoinositide metabolism in brain in vivo

1978 ◽  
Vol 27 (8) ◽  
pp. 1239-1243 ◽  
Author(s):  
Joseph F. Soukup ◽  
Robert O. Friedel ◽  
Saul M. Schanberg
Keyword(s):  
Cholinergic Stimulation ◽  
Stimulation Of ◽  
Polyphosphoinositide Metabolism

scholarly journals A method for measuring relative changes in guanosine 3′:5′-cyclic monophosphate in mouse neuroblastoma cells on muscarinic cholinergic stimulation

1978 ◽  
Vol 176 (2) ◽  
pp. 583-590 ◽  
Author(s):  
P G Strange
Keyword(s):  
Cyclic Gmp ◽  
Time Course ◽  
Neuroblastoma Cells ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Cell Labelling ◽  
Cholinergic Stimulation ◽  
Mouse Neuroblastoma ◽  
Muscarinic Cholinergic ◽  
Stimulation Of

A convenient, inexpensive assay was developed for measuring relative changes in cyclic GMP in whole mouse neuroblastoma cells (clone NIE 115) based on labelling the cellular GTP pool with [8(-3)H]guanine. The time course of cell labelling and the distribution of radioactivity among possible products were studied; GTP is the only major labelled species. Radioactive cyclic GMP produced from the radioactive GTP on cell stimulation is isolated by column chromatography nad its identity has been rigorously established by paper chromatography and ion-exchange chromatography. The assay was used to study the time course of the cyclic GMP changes that occur after stimulation of neuroblastoma cells with carbamoylcholine and the dependence of the cyclic GMP changes on the carbamoylcholine concentration. The assay gives results comparable with those obtained by using a radioimmunoassay for cyclic GMP and should be applicable to other whole-cell and tissue-slice systems.

Backdiffusion of H+ in isolated frog gastric mucosa

1984 ◽  
Vol 246 (2) ◽  
pp. G114-G119
Author(s):  
R. P. Durbin
Keyword(s):  
Gastric Mucosa ◽  
Ion Pair ◽  
Substantial Part ◽  
Direct Titration ◽  
Maximal Stimulation ◽  
Gastric Potential Difference ◽  
Normal Resistance ◽  
Order Of Magnitude ◽  
Stimulation Of

Backdiffusion of H+ was studied in isolated bullfrog gastric mucosa using direct titration to evaluate changes in luminal H+ level. In resting mucosae, the resulting permeability coefficient for H+ (uncorrected for electrical effects) was 0.4 X 10(-5) cm X S-1, which is of the same order of magnitude as that estimated from data in the literature for dog and rabbit gastric mucosa in vivo. With maximal stimulation of acid secretion, backdiffusion of H+ was considerably increased. In both resting and stimulated mucosae, an increase in Cl- flux from lumen to serosa was observed to accompany H+ backdiffusion. In experiments in which electrical activity of resting mucosae was monitored, instilled H+ lowered gastric potential difference but had little effect on the normal resistance. Sudden drops in resistance and potential were observed, independent of luminal acid; after such events instilled H+ had no effect on mucosal resistance. It appears that a substantial part of H+ backdiffusion occurs as the ion pair HCl.

EFFECT OF LUTEINIZING HORMONE ON THE CONCENTRATION OF CYCLIC GMP IN RABBIT OVARIES

1978 ◽  
Vol 79 (2) ◽  
pp. 251-252
Author(s):  
V. V. PATWARDHAN ◽  
A. LANTHIER
Keyword(s):  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Ovarian Tissue ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Direction Opposite ◽  
Stimulation Of

Laboratoire d'Endocrinologie, Hôpital Notre-Dame et Département de Medicine, Université de Montréal, Montréal, Canada (Received 28 June 1978) Cyclic AMP has been implicated as an intermediate in some of the actions of luteinizing hormone (LH) on ovarian tissues, such as stimulation of steroidogenesis (LeMaire & Marsh, 1975). Both in vitro (Marsh, Butcher, Savard & Sutherland, 1966) and in vivo (Armstrong, Dorrington & Robinson, 1976), stimulation with LH results in a rapid increase in the amount of cyclic AMP in ovarian tissues, which precedes the LH-induced increase in steroidogenesis. Recently, studies on rat ovaries (Grinwich, Ham, Hichens & Behrman, 1976; Ratner, 1976; Ratner & Sanborn, 1976) have indicated that the ovarian tissue content of cyclic GMP may also be regulated by LH, but in a direction opposite to that of cyclic AMP. In the rabbit, Goff & Major (1975) have shown that administration of human chorionic gonadotrophin (HCG) causes a biphasic increase

scholarly journals Nonequilibrium kinetics of a cyclic GMP-binding protein in dictyostelium discoideum

1982 ◽  
Vol 94 (2) ◽  
pp. 271-278 ◽  
Author(s):  
PJM Van Haastert ◽  
H Van Walsum ◽  
FJ Pasveer
Keyword(s):  
Dictyostelium Discoideum ◽  
Cyclic Gmp ◽  
Binding Proteins ◽  
Binding Protein ◽  
Kinetic Constants ◽  
Nonequilibrium Conditions ◽  
Kinetics Of ◽  
Stimulation Of

Chemoattractants added to cells of the cellular slime mold dictyostelium discoideum induce a transient elevation of cyclic GMP levels, with a maximum at 10 s and a recovery of basal levels at approximately 25 s after stimulation. We analyzed the kinetics of an intracellular cGMP binding protein in vitro and in vivo. The cyclic GMP binding protein in vitro at 0 degrees C can be described by its kinetic constants K(1)=2.5 x 10(6) M(- 1)s(-1), k(-1)=3.5 x 10(-3)s(-1), K(d)=1.4 x 10(-9) M, and 3,000 binding sites/cell. In computer simulation experiments the occupancy of the cGMP binding protein was calculated under nonequilibrium conditions by making use of the kinetic constants of the binding protein and of the shape of the cGMP accumulations. These experiments show that under nonequilibrium conditions by making use of the kinetic constants of the binding protein and the shape of the cGMP accumulations. These experiments show that under nonequilibrium conditions the affinity of the binding protein for cGMP is determined by the rate constant of association (k(1)) and not by the dissociation constant (k(d)). Experiments in vivo were performed by stimulation of aggregative cells with the chemoattractant cAMP, which results in a transient cGMP accumulation. At different times after stimulation with various cAMP concentrations, the cells were homogenized and immediately thereafter the number of binding proteins which were not occupied with native cGMP were determined. The results of these experiments in vivo are in good agreement with the results of the computer experiments. This may indicate that: (a) The cGMP binding protein in vivo at 22 degrees C can be described by its kinetic constants: K(1)=4x10(6)M(-1)s(-1) and K(-1)=6x10(-3)s(-1). (b) Binding the cGMP to its binding protein is transient with a maximum at about 20-30 s after chemotactic stimulation, followed by a decay to basal levels, with a half-life of approximately 2 min. (c) The cGMP to its binding proteins get half maximally occupied at a cGMP accumulation of δ[cGMP](10)=2x10(-8) M, which corresponds to an extracellular stimulation of aggregative cells by 10(-10) M cAMP. (d) Since the mean basal cGMP concentration is approximately 2x10(-7) M, the small increase of cGMP cannot be detected accurately. Therefore the absence of a measurable cGMP accumulation does not argue against a cGMP function. (e) There may exist two compartments of cGMP: one contains almost all the cGMP of unstimulated cells, and the other contains cGMP binding proteins and the cGMP which accumulates after chemotactic stimulation. (f) From the kinetics of binding, the cellular responses to the chemoattractant can be divided into two classes: responses which can be mediated by this binding protein (such as light scattering, proton extrusion, PDE induction, and chemotaxis) and responses which cannot be (solely) mediated by this binding protein such as rlay, refractoriness, phospholipids methylation, and protein methylation.

Surfactant secretion: evidence that cholinergic stimulation of secretion is indirect

1982 ◽  
Vol 243 (1) ◽  
pp. C39-C45 ◽  
Author(s):  
D. Massaro ◽  
L. Clerch ◽  
G. D. Massaro
Keyword(s):  
Cholinergic Stimulation ◽  
Alveolar Cells ◽  
Isolated Perfused Lung ◽  
Surfactant Secretion ◽  
Perfused Lung ◽  
Bilateral Vagotomy ◽  
Cholinergic Agents ◽  
Stimulation Of

There is strong evidence that cholinergic agents stimulate the secretion of surfactant in vivo and in the isolated perfused lung and that they do not stimulate surfactant secretion in isolated type 2 alveolar cells. These observations suggest that in multicellular systems the cholinergic effect is indirect. In the present work we have accrued the following support for this hypothesis. 1) Propranolol blocked the in vivo stimulation of disaturated phosphatidylcholine (DSPC) secretion by pilocarpine. 2) Bilateral adrenalectomy decreased by 50% the in vivo stimulation of DSPC secretion by pilocarpine. 3) Bilateral vagotomy did not block the increased secretion of DSPC produced in vivo by periodic deep inflations. 4) Pilocarpine (10(-7) M) stimulated DSPC secretion in the isolated perfused lung, and this effect was blocked by indomethacin as well as by atropine. We conclude that cholinergic stimulation of the secretion of surfactant in rats is indirect, i.e., cholinergic agonists do not stimulate the secretion of surfactant by acting directly on type 2 alveolar cells.

Stimulation of ovarian progesterone secretion by oxytocin in vivo

1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S199-S200
Author(s):  
E. DIETRICH ◽  
K. RENTELMANN ◽  
W. WUTTKE
Keyword(s):  
Progesterone Secretion ◽  
Stimulation Of
Sign in / Sign up

Export Citation Format

Share Document