Release and reloading of intracellular Ca stores after cholinergic stimulation of the parietal cell

1988 ◽  
Vol 254 (4) ◽  
pp. C498-C504 ◽  
Author(s):  
P. A. Negulescu ◽  
T. E. Machen
Keyword(s):  
Plasma Membrane ◽  
Parietal Cell ◽  
Base Line ◽  
Cholinergic Stimulation ◽  
Gastric Glands ◽  
Cholinergic Agonist ◽  
Intracellular Ca ◽  
Lanthanum Ion ◽  
Intact Rabbit ◽  
Stimulation Of

Microspectrofluorimetry was used to measure cytosolic free Ca, Cai, in single parietal cells of intact rabbit gastric glands loaded with the Ca-sensitive fluorescent dye, fura-2. Cells were repeatedly stimulated with the cholinergic agonist carbachol to gain insights into the membrane mechanisms involved in hormonally stimulated Ca metabolism. In either Ca-containing or Ca-free solutions, carbachol (100 microM) caused a rapid (within 30 s) elevation of Cai from a resting level of 100 nM to greater than 600 nM. After the spike, Cai decreased within 3 min to a lower level that was somewhat elevated (greater than 200 nM) over base line. This plateau was dependent on both carbachol and extracellular Ca (Cao) and could be blocked by the addition of atropine (1 microM) or lanthanum ion (La, 50 microM). The spike is due to the release of Ca from internal stores, whereas the plateau is due to Ca entry across the plasma membrane through agonist-controlled, La-inhibitable channels. After a carbachol stimulation of 3 min or longer, reloading of the internal store was absolutely dependent on Cao. Under these conditions, reloading occurred through a La-sensitive (but nifedipine- and verapamil-insensitive) pathway in the plasma membrane. No significant change in Cai was detectable during the reloading. In contrast to the longer treatments, if carbachol stimulation was terminated with atropine while Cai was still elevated, significant reloading occurred from the cytosol.(ABSTRACT TRUNCATED AT 250 WORDS)

Ca2+ metabolism during cholinergic stimulation of acid secretion

1985 ◽  
Vol 248 (2) ◽  
pp. G216-G228 ◽  
Author(s):  
S. Muallem ◽  
G. Sachs
Keyword(s):  
Plasma Membrane ◽  
Membrane Permeability ◽  
Parietal Cell ◽  
Membrane Vesicles ◽  
Parietal Cells ◽  
Cell Manipulation ◽  
Cholinergic Stimulation ◽  
Gastric Glands ◽  
Intact Cells ◽  
Lateral Membrane

Carbachol-induced changes in 45Ca fluxes and cytosolic free Ca2+ were characterized in rabbit gastric glands and isolated dog parietal cells. Cholinergic stimulation was expressed as changes in the membrane permeability of the parietal cell to Ca2+ without Ca2+ release from intracellular stores. The changes in the membrane permeability to Ca2+ were sustained as long as the cells were exposed to carbachol, independent of extracellular Ca2+, and had the properties of a passive pathway across which Ca2+ distributed according to its chemical gradient. As a consequence of the changes in membrane permeability to Ca2+, carbachol caused a sustained increase in free cytosolic Ca2+ from a resting level of 134 +/- 11 to 533 +/- 81 nM (n = 14). After carbachol stimulation, calcium ions were sequestered in mitochondrial and probably nonmitochondrial compartments. When cell stimulation was terminated by atropine or La3+, the cells restored the resting level of the intracellular Ca2+ activity ([Ca2+]in), independent of uncoupling of mitochondrial oxidation phosphorylation. Reduction in [Ca2+]in was mainly through Ca2+ efflux across the plasma membrane of the parietal cell. Manipulation of intracellular Na+ ion activity in intact cells and studies with basal-lateral membrane vesicles from gastric mucosa indicated the absence of extracellular Na+-intracellular Ca2+ exchange activity in the plasma membrane of the parietal cell. A calmodulin-regulated, ATP-dependent Ca2+ pump that could maintain active Ca2+ extrusion from parietal cells was found in the basal-lateral membrane of the parietal cells.

Intracellular Ca requirements for stimulus-secretion coupling in parietal cell

1989 ◽  
Vol 256 (2) ◽  
pp. C241-C251 ◽  
Author(s):  
P. A. Negulescu ◽  
W. W. Reenstra ◽  
T. E. Machen
Keyword(s):  
Parietal Cell ◽  
Acid Production ◽  
Dose Dependence ◽  
Maximal Response ◽  
Dependent Manner ◽  
Gastric Glands ◽  
Intracellular Ca ◽  
Intact Rabbit ◽  
Stimulus Secretion Coupling

The role of cytosolic free Ca (Cai) in stimulating acid production by the parietal cell in response to the secretagogues carbachol (carb), histamine (hist), and dibutyryl adenosine 3',5'-cyclic monophosphate plus 3-isobutyl-1-methylxanthine (DBcAMP + IBMX) was evaluated. Microfluorimetry with fura-2 was used to measure Cai in single parietal cells within intact rabbit gastric glands. Acid production was determined in parallel experiments by monitoring the accumulation of [14C]aminopyrine (AP) in suspensions of glands. Carb increased peak Cai levels to 1 microM in a dose-dependent manner [concentration for half-maximal response (K0.5) = 8 microM] that correlated well with the dose dependence of carb-stimulated AP accumulation (K0.5 = 18 microM). The Ca chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) was used to attenuate secretagogue-induced Cai increases. Incubating glands for 10 min with 1 and 10 microM BAPTA/AM caused resting Cai to decrease from 119 to 93 and 80 nM, respectively. BAPTA/AM, 1 and 10 microM, blocked carb-stimulated increases in Cai by 60 and 90% and AP accumulation by 50 and 90%. Hist, which increases cytosolic cAMP, caused small and relatively infrequent increases in Cai. Even so, hist-stimulated AP accumulation was inhibited 8 and 40% by 1 and 10 microM BAPTA. DBcAMP had no effect on Cai, and AP accumulation caused by DBcAMP was unaffected by the concentrations of BAPTA tested. These data suggest that carb requires an increase in Cai as a secretory signal. Hist also exhibited some Cai dependence, which may be attributable to either a small increase in Cai or the necessity of having a specific basal level of Cai. A Cai requirement for DBcAMP-stimulated acid secretion was not detected. Thus the parietal cell possesses both Ca-dependent and Ca-independent stimulatory pathways, and at least one secretagogue (hist) may utilize both pathways.

Intracellular Ca regulation during secretagogue stimulation of the parietal cell

1988 ◽  
Vol 254 (1) ◽  
pp. C130-C140 ◽  
Author(s):  
P. A. Negulescu ◽  
T. E. Machen
Keyword(s):  
Acid Secretion ◽  
Phosphodiesterase Inhibitor ◽  
Parietal Cells ◽  
Channel Blockers ◽  
Ca Channel ◽  
Gastric Glands ◽  
Intracellular Store ◽  
H2 Antagonist ◽  
Intracellular Ca ◽  
Stimulation Of

Intracellular [Ca] ([Ca]i) was measured following secretagogue stimulation of rabbit gastric glands loaded with the Ca-sensitive dye fura-2. Glands were mounted on cover slips and placed either in a perfused cuvette (for spectrofluorimetric measurements on whole glands) or in a chamber on the stage of a microscope (for microspectrofluorimetric measurements on single parietal cells within a gland). In parietal cells resting [Ca]i = 91 nM. Either histamine or carbachol caused [Ca]i to increase (spike) rapidly (within 5 s) to greater than 425 nM by releasing Ca from an intracellular store. The two hormones acted on the same store, with carbachol being the more potent releaser. The spike occurred equally well in solutions containing the Ca channel blockers verapamil, nifedipine, Co, or La. After the spike, [Ca]i decreased to a plateau level (130-200 nM) that was dependent on the presence of secretagogue but was independent from the release of the intracellular store. This plateau persisted (up to 40 min) until the addition of antagonist or until the removal of either extracellular Ca or the agonist. Histamine and carbachol were specifically blocked by the H2-antagonist cimetidine and the muscarinic antagonist atropine, respectively. Histamine often induced repeated increases in [Ca]i. A combination of dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) and the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) had no effect on [Ca]i, but if cells were pretreated with histamine, DBcAMP + IBMX would cause [Ca]i to increase. Because exposure to DBcAMP + IBMX stimulates acid secretion yet does not affect [Ca]i, two independent pathways to acid secretion may exist.

Multiple effects of phorbol ester on secretory activity in rabbit gastric glands and parietal cells

1987 ◽  
Vol 65 (9) ◽  
pp. 1840-1847 ◽  
Author(s):  
Milton R. Brown ◽  
Catherine S. Chew
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Acid Secretion ◽  
Cholera Toxin ◽  
Parietal Cell ◽  
Pertussis Toxin ◽  
Secretory Activity ◽  
Gastric Glands ◽  
Kinase C ◽  
Stimulation Of

Acid secretory activity and respiration in rabbit gastric glands are stimulated by cAMP-dependent and -independent agonists. Potentiation between agonists suggests interaction of the activation pathways. Regulation of secretory response by protein kinase C was investigated with 12-O-tetradecanoyl phorbol-13-acetate (TPA). TPA elevated basal respiration, pepsin release, and acid secretion but inhibited histamine and carbachol stimulation of acid secretion by gastric glands, as measured by [dimethylamino-14C]aminopyrine accumulation. The inhibition of histamine response was specific for protein kinase C activators, occurred after a 20-min lag, and was not reversed by removal of TPA after 3 min of preincubation. TPA pretreatment inhibited acid secretory responses to cholera toxin and forskolin but enhanced the response to cAMP analogues. Cholera toxin and pertussis toxin simulated ADP-ribosylation of 45 and 41 kDa proteins, respectively, in parietal cell membranes. Therefore, both stimulatory (Gs) and inhibitory (Gi) GTP binding proteins of adenylyl cyclase appear to be present in parietal cells. Pretreatment with pertussis toxin attenuated PGE2 but not TPA inhibition of histamine stimulation of aminopyrine accumulation. Thus, the inhibitory effect of TPA does not appear to be associated with an action on Gi. The results with histamine and carbachol suggest that protein kinase C may regulate both cAMP-dependent and -independent stimulation of parietal cell acid secretion.

Effect of substance P and neurokinin A on rat parietal cell function

1990 ◽  
Vol 259 (4) ◽  
pp. G646-G654
Author(s):  
W. Schepp ◽  
J. Schmidtler ◽  
C. Tatge ◽  
V. Schusdziarra ◽  
M. Classen
Keyword(s):  
Substance P ◽  
Parietal Cell ◽  
Pertussis Toxin ◽  
Cell Function ◽  
Inhibitory Effect ◽  
Parietal Cells ◽  
Neurokinin A ◽  
Cholinergic Stimulation ◽  
Camp Production ◽  
Stimulation Of

In enzymatically dispersed enriched (76%) rat parietal cells we studied the effect of substance P on acid sequestration as indirectly measured by [14C]aminopyrine accumulation. Substance P (10(-8)-10(-5) M) had no effect on basal [14C]aminopyrine accumulation. Yet, the peptide reduced the response to histamine and to the postreceptor agonists forskolin and dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP). Inhibition by substance P followed noncompetitive kinetics and reduced stimulated parietal cell function by up to 45% at 10(-5) M. The antagonist [D-Pro2, D-Trp7,9]-substance P at 10(-5) M partly reversed the inhibitory effect of substance P. Cholinergic stimulation of [14C]aminopyrine accumulation was not reduced by substance P. Neurokinin A, another tachykinin that is structurally related to substance P, was of comparable potency and efficacy in reducing [14C]aminopyrine accumulation in response to histamine, forskolin, and DBcAMP. Inhibition of forskolin- or DBcAMP-induced [14C]aminopyrine accumulation persisted in the presence of 10(-5) M ranitidine. Inhibition by substance P and neurokinin A of the response to histamine was not sensitive to pertussis toxin. Both tachykinins failed to reduce histamine- and forskolin-stimulated cAMP production. Our data suggest that substance P and neurokinin A exert a direct effect on rat parietal cells. They attenuate histamine-stimulated acid sequestration at an intracellular step that is distal to the adenylate cyclase and that does not involve pertussis toxin-sensitive GTP-binding proteins.

Role of Ca2+ channels in NE-induced increase in [Ca2+]iand tension in fetal and adult cerebral arteries

1999 ◽  
Vol 277 (1) ◽  
pp. R286-R294 ◽  
Author(s):  
Wen Long ◽  
Yu Zhao ◽  
Lubo Zhang ◽  
Lawrence D. Longo
Keyword(s):  
Plasma Membrane ◽  
Cerebral Arteries ◽  
Channel Blockers ◽  
Developmental Age ◽  
Intracellular Ca ◽  
Lanthanum Ion ◽  
Near Term ◽  
Dose Dependent Decrease ◽  
Nonpregnant Adult

In vascular smooth muscle, elevation of agonist-induced intracellular Ca2+ concentration ([Ca2+]i) occurs via both Ca2+ release from intracellular stores and Ca2+influx across the plasma membrane. In the cerebral vasculature of the fetus and adult the relative roles of these mechanisms have not been defined. To test the hypothesis that plasma membrane L-type and receptor-operated Ca2+ channels play a key role in NE-induced vasoconstriction via alterations in plasma membrane Ca2+ flux and that this may change with developmental age, we performed the following study. In main branch middle cerebral arteries (MCA) from near-term fetal (∼140 days) and nonpregnant adult sheep, we quantified NE-induced responses of vascular tension and [Ca2+]i(by use of fura 2) under standard conditions in response to several Ca2+ channel blockers and in response to zero extracellular Ca2+. In fetal and adult MCA, maximal NE-induced tensions (g) were 0.91 ± 0.12 ( n = 10) and 1.61 ± 0.13 ( n = 12), respectively. The pD2 values for NE-induced tension were both 6.0 ± 0.1, whereas the fetal and adult maximum responses (%Kmax) were 107 ± 16 and 119 ± 7, respectively. The fetal and adult pD2 values for NE-induced increase of [Ca2+]iwere 6.2 ± 0.1 and 6.4 ± 0.1, respectively, whereas maximum [Ca2+]iresponses were 81 ± 9 and 103 ± 15% of Kmax, respectively. After 10−5 M NE-induced contraction, nifedipine resulted in dose-dependent decrease in vessel tone and [Ca2+]iwith pIC50 values for fetal and adult tensions of 7.3 ± 0.1 and 6.6 ± 0.1, respectively ( P < 0.01; n = 4 each), whereas pIC50 for [Ca2+]iresponses were 7.2 ± 0.1 and 6.9 ± 0.1, respectively. The pIC50 values for tension for diltiazem and verapamil were somewhat lower but showed a similar relationship. The receptor-operated Ca2+ channel blocker 2-nitro-4 carboxyphenyl- N,N-diphenyl carbamate showed little effect on NE-induced vessel contractility or [Ca2+]i. In the absence of extracellular Ca2+ for 2 min, 10−5 M NE resulted in markedly attenuated responses of adult MCA tension and [Ca2+]ito 39 ± 7 and 73 ± 8% of control values ( n = 4). For fetal MCA, exposure to extracellular Ca2+concentration resulted in essentially no contractile or [Ca2+]iresponse ( n = 4). Similar blunting of NE-induced tension and [Ca2+]iwas seen in response to 10−3M lanthanum ion. These findings provide evidence to suggest that especially in fetal, but also in adult, ovine MCA, Ca2+ flux via L-type calcium channels plays a key role in NE-induced contraction. In contrast, Ca2+ flux via receptor-operated Ca2+ channels is of less importance. This developmental difference in the role of cerebrovascular plasma membrane Ca2+ channels may be an important association with increased Ca2+sensitivity of the fetal vessels.

scholarly journals Calcium- and proton-dependent relocation of annexin A6 in Jurkat T cells stimulated for interleukin-2 secretion.

2007 ◽  
Vol 54 (2) ◽  
pp. 261-271 ◽  
Author(s):  
Paulina Podszywalow-Bartnicka ◽  
Agnieszka Strzelecka-Kiliszek ◽  
Joanna Bandorowicz-Pikula ◽  
Slawomir Pikula
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
Secretory Granules ◽  
Intracellular Localization ◽  
Interleukin 2 ◽  
Jurkat T Cells ◽  
Vesicular Traffic ◽  
Early Endosomes ◽  
Intracellular Ca ◽  
Stimulation Of

Annexin A6 (AnxA6) is a Ca(2+)-dependent membrane-binding protein involved in vesicular traffic. The likely participation of AnxA6 in the response of lymphocytes to Ca(2+) signals has not been investigated yet. The present study focuses on intracellular relocation of AnxA6 in human Jurkat T lymphoblasts upon stimulation followed by transient increase of intracellular [Ca(2+)] and exocytosis of interleukin-2 (IL-2). Stimulation of the cells under different experimental conditions (by lowering pH and/or by rising extracellular [Ca(2+)] in the presence of ionomycin) induced time-dependent transients of intracellular [Ca(2+)] and concomitant changes in AnxA6 intracellular localization and in IL-2 secretion, with only minor effects on cell viability and apoptosis. In resting conditions (in the presence of EGTA or with no ionophore) AnxA6 was localized uniformly in the cytosol, whereas it translocated to vesicular structures beneath the plasma membrane within 5 min following stimulation of Jurkat T cells and rise of intracellular [Ca(2+)] at pH 7.4. Lowering the extracellular pH value from 7.4 to 6.0 significantly enhanced this process. AnxA6 changed its location from the cytosol to the secretory granules and early endosomes which seem to represent membranous targets for annexin. In conclusion, AnxA6 is sensitive to variations in intracellular [Ca(2+)] upon stimulation of Jurkat T cells, as manifested by a switch in its intracellular localization from the cytosol to vesicular structures located in close proximity to the plasma membrane, suggestive of participation of AnxA6 in calcium- and proton-dependent secretion of cytokines by lymphocytes.

Ca2+-dependent p47phox translocation in hydroperoxide modulation of the alveolar macrophage respiratory burst

1997 ◽  
Vol 273 (5) ◽  
pp. L1042-L1047 ◽  
Author(s):  
Huanfang Zhou ◽  
Roger F. Duncan ◽  
Timothy W. Robison ◽  
Lin Gao ◽  
Henry Jay Forman
Keyword(s):  
Oxidative Stress ◽  
Plasma Membrane ◽  
Alveolar Macrophages ◽  
Respiratory Burst ◽  
Tert Butyl Hydroperoxide ◽  
Intracellular Ca ◽  
Induced Changes ◽  
Respiratory Burst Oxidase ◽  
Dependent Processes ◽  
Stimulation Of

Oxidative stress produces dual effects on the respiratory burst of rat alveolar macrophages. Preincubation with hydroperoxide concentrations [H2O2or tert-butyl hydroperoxide ( t-BOOH); <50 μM] enhances stimulation of the respiratory burst, whereas higher concentrations inhibit stimulation. Both the enhancement and inhibition are markedly attenuated by buffering t-BOOH-induced changes in intracellular Ca2+concentration ([Ca2+]i). Phosphorylation of the NADPH oxidase component p47phox and its translocation from cytoplasm to plasma membrane are essential in respiratory burst activation. Phorbol 12-myristate 13-acetate (PMA)-stimulated p47phox phosphorylation was negligibly affected by 25 or 100 μM t-BOOH. Nonetheless, 25 μM t-BOOH increased PMA-stimulated p47phox translocation, whereas 100 μM t-BOOH decreased PMA-stimulated translocation. In unstimulated cells, however, neither phosphorylation nor translocation of p47phox was affected by t-BOOH. Buffering of the t-BOOH-mediated changes of [Ca2+]iabolished the effects of t-BOOH on PMA-stimulated translocation in parallel to effects upon the respiratory burst. The results suggest that the dual effects of hydroperoxides are mediated, in part, by Ca2+-dependent processes affecting the assembly of the respiratory burst oxidase at steps that are separate from p47phoxphosphorylation.

scholarly journals Intracellular Ca2+Release Triggers Translocation of Membrane Marker FM1–43 from the Extracellular Leaflet of Plasma Membrane into Endoplasmic Reticulum in T Lymphocytes

2005 ◽  
Vol 280 (16) ◽  
pp. 16377-16382 ◽  
Author(s):  
Sepehr Dadsetan ◽  
Vyacheslav Shishkin ◽  
Alla F. Fomina
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
T Cell ◽  
T Cell Receptor ◽  
Membrane Trafficking ◽  
Cell Receptor ◽  
Multivesicular Bodies ◽  
Close Proximity ◽  
Intracellular Ca ◽  
Stimulation Of

Stimulation of T cell receptor in lymphocytes enhances Ca2+signaling and accelerates membrane trafficking. The relationships between these processes are not well understood. We employed membrane-impermeable lipid marker FM1–43 to explore membrane trafficking upon mobilization of intracellular Ca2+in Jurkat T cells. We established that liberation of intracellular Ca2+with T cell receptor agonist phytohemagglutinin P or with Ca2+-mobilizing agents ionomycin or thapsigargin induced accumulation of FM1–43 within the lumen of the endoplasmic reticulum (ER), nuclear envelope (NE), and Golgi. FM1–43 loading into ER-NE and Golgi was not mediated via the cytosol because other organelles such as mitochondria and multivesicular bodies located in close proximity to the FM1–43-containing ER were free of dye. Intralumenal FM1–43 accumulation was observed even when Ca2+signaling in the cytosol was abolished by the removal of extracellular Ca2+. Our findings strongly suggest that release of intracellular Ca2+may create continuity between the extracellular leaflet of the plasma membrane and the lumenal membrane leaflet of the ER by a mechanism that does not require global cytosolic Ca2+elevation.

scholarly journals Epidermal growth factor activates cytosolic [Ca2+] elevations and subsequent membrane permeabilization in mouse cumulus–oocyte complexes

Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 207-220 ◽  
Author(s):  
John B O'Donnell ◽  
Julia L Hill ◽  
David J Gross
Keyword(s):  
Plasma Membrane ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Membrane Permeabilization ◽  
Intracellular Ca ◽  
Epidermal Growth ◽  
Plasma Membrane Permeabilization ◽  
Stimulation Of

The role of epidermal growth factor (EGF) in the maturation of mammalian oocytes is well known but not well characterized. It is known that EGF enhances oocyte maturationin vitroand that EGF stimulation of cumulus–oocyte complexes (COCs) induces pulsatile Ca2+efflux from the cell complex. By use of quantitative Fura-2 imaging, EGF-stimulated changes in intracellular [Ca2+] in germinal vesicle stage murine COCs are shown to occur in a subpopulation of cumulus cells that interact cooperatively within individual COCs. Oocytes fail to respond to EGF stimulus. In many of the cumulus cells responding with a rise in intracellular [Ca2+], a concomitant permeabilization of the plasma membrane is found. Neither cumulus cells of control COCs nor those that show a rise in intracellular [Ca2+] in response to calcium ionophore treatment display a similar membrane permeabilization, although those cells responding with a prolonged [Ca2+] increase in response to thimerosal or thapsigargin do display plasma membrane permeabilization. Thus, EGF stimulation of mammalian COCs activates release of Ca2+from intracellular stores of cumulus cells, the depletion of which activates permeabilization of the plasma membrane. This membrane permeabilization leads to loss of cell contents and presumptive cumulus cell death. This catastrophic EGF-induced plasma membrane permeabilization of individual cumulus cells within a COC leads to pulsatile Ca2+efflux as previously seen, and may lead to improved cumulus cell expansion during COC maturation.

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