Histamine and cyclic AMP in isolated canine parietal cells.

1979 ◽  
Vol 237 (5) ◽  
pp. E444 ◽  
Author(s):  
A H Soll ◽  
A Wollin
Keyword(s):  
Oxygen Consumption ◽  
Cyclic Amp ◽  
Parietal Cells ◽  
Histamine Stimulation ◽  
Close Relationship ◽  
The Relationship ◽  
Parallel Fashion ◽  
Stimulation Of

The relationship between cyclic AMP production and the response of isolated canine parietal cells to histamine has been examined. Histamine increased cyclic AMP generation, and this effect correlated with histamine stimulation of oxygen consumption and aminopyrine accumulation. Metiamide inhibited histamine-stimulated cyclic AMP generation and oxygen consumption in a parallel fashion. At concentrations below 100 microM, isobutyl AMP production and oxygen consumption in a similar fashion. However, with IMX above 100 microM, histamine caused no further increases in oxygen consumption, despite markedly enhanced cyclic AMP generation. Neither carbachol nor gastrin increased cyclic AMP production beyond that produced by IMX alone, and the combinations of histamine and carbachol and of histamine and gastrin produced no greater cyclic AMP generation than produced by histamine. These findings support a close relationship between cyclic AMP production and the action of histamine but not of carbachol or gastrin on isolated parietal cells. The mechanisms underlying the potentiating interactions between histamine, carbachol, and gastrin involve step(s) beyond stimulation of cyclic AMP generation.

Integrative effects of EGF on metabolism and proliferation in renal proximal tubular cells

1995 ◽  
Vol 269 (5) ◽  
pp. C1317-C1325 ◽  
Author(s):  
G. Nowak ◽  
R. G. Schnellmann
Keyword(s):  
Oxygen Consumption ◽  
Acid Synthesis ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Epidermal Growth ◽  
Renal Proximal Tubular Cells ◽  
Renal Proximal Tubular ◽  
The Relationship ◽  
Stimulation Of

This study examined the relationship between alterations in cellular metabolism and induction of proliferation in renal proximal tubular cells (RPTC) after epidermal growth factor (EGF) exposure. EGF treatment (10 ng/ml) of confluent RPTC cultures for 6 consecutive days increased monolayer DNA content 3.3-fold. EGF-stimulated proliferation of RPTC was preceded by a rapid (within 4 h) induction of glycolysis and a decrease in basal and ouabain-sensitive oxygen consumption (20 and 30%, respectively). EGF stimulated the pentose cycle by 58% and decreased gluconeogenesis by 48%. Supplementation of the culture medium with ribose-5-phosphate or ribose abolished the stimulation of glycolysis and the pentose cycle by EGF but had no effect on proliferation. These results show that EGF rapidly stimulates the pentose cycle, shifts glucose metabolism from gluconeogenesis to glycolysis, and decreases oxygen consumption before any increase in proliferation. The lack of an EGF effect on the pentose cycle and glycolysis in the presence of exogenous precursors for DNA synthesis suggests that the stimulation of these pathways before proliferation is due to increased demands for ribose for subsequent nucleic acid synthesis.

scholarly journals Inhibition by calcium ions of adenosine cyclic monophosphate formation in sealed pigeon erythrocyte ‘ghosts’. A study using the photoprotein obelin

1978 ◽  
Vol 176 (1) ◽  
pp. 53-66 ◽  
Author(s):  
A K Campbell ◽  
R L Dormer
Keyword(s):  
Cyclic Amp ◽  
Initial Rate ◽  
Ionophore A23187 ◽  
Erythrocyte Ghosts ◽  
Adrenergic Agonists ◽  
Intact Cells ◽  
Beta Adrenergic ◽  
Beta Adrenergic Agonists ◽  
The Relationship ◽  
Stimulation Of

1. Sealed pigeon erythrocyte ‘ghosts’ were prepared containing ATP and the Ca2+-activated photoprotein obelin to investigate the relationship cyclic AMP formation and internal free Ca2+. 2. The ‘ghosts’ were characterized by (a) morphology (optical and electron microscopy), (b) composition (haemoglobin, K+, Na+, Mg2+, ATP, obelin), (c) permeability to Ca2+, assessed by obelin luminescence and (d) hormone sensitivity (the effect of beta-adrenergic agonists and antagonists on cyclic AMP formation). 3. The effect of osmolarity at haemolysis and ATP at resealing on these parameters was investigated. 4. Sealed ‘ghosts’, containing approx. 2% of original haemoglobin, 150mM-K+, 0.5MM-ATP, 10(3)–10(4) obelin luminescence counts/10(6) ‘ghosts’, which were relatively impermeable to Ca2+ and in which cyclic AMP formation was stimulated by beta-adrenergic agonists over a concentration range similar to that for intact cells, could be prepared after haemolysis in 6mM-NaCl3mM-MgCl2/50mM-Tes, pH7, and resealing for 30min at 37 degrees C in the presence of ATP and 150mM-KCl. 5. The initial rate of adrenaline-stimulated cyclic AMP formation in these ‘ghosts’ was 30–50% of that in intact cells and was inhibited by the addition of extracellular Ca2+. Addition of Ca2+ to the ‘ghosts’ resulted in a stimulation of obelin luminescence, indicating an increase in internal free Ca2+ under these conditions. 6. The ionophore A23187 increased the rate of obelin luminescence in the ‘ghosts’ and also inhibited the adrenaline-stimulated increase in cyclic AMP. 7. The effect of ionophore A23187 on obelin luminescence and on cyclic AMP formation in the ‘ghosts’ was markedly decreased by sealing EGTA inside the ‘ghosts’. 8. It was concluded that cyclic AMP formation inside sealed pigeon erythrocyte ‘ghosts’ could be inhibited by more than 50% by free Ca2+ concentrations in the range 1–10 micrometer.

scholarly journals MEDIATION OF IMMUNOLOGIC DISCHARGE OF LYSOSOMAL ENZYMES FROM HUMAN NEUTROPHILS BY GUANOSINE 3',5'-MONOPHOSPHATE

1974 ◽  
Vol 140 (1) ◽  
pp. 225-238 ◽  
Author(s):  
L. J. Ignarro ◽  
W. J. George
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Lysosomal Enzymes ◽  
Extracellular Calcium ◽  
Human Neutrophils ◽  
Enzyme Release ◽  
Dibutyryl Cyclic Amp ◽  
Relationship Of ◽  
The Relationship ◽  
Stimulation Of

The purpose of this investigation was to elucidate the relationship of cyclic GMP and calcium to the immunologic discharge of lysosomal enzymes from purified human neutrophils. Contact of neutrophils with a variety of immunologic stimuli, including zymosan particles treated with either normal or rheumatoid arthritic (RA) serum, heat-aggregated (agg) IgG, particulate and immobilized agg IgG each treated with RA serum, and zymosan-treated serum, provoked the discharge of ß-glucuronidase, but not cytoplasmic lactate dehydrogenase, and stimulated the accumulation of cyclic GMP. Both enzyme release and elevation of cyclic GMP levels required the presence of extracellular calcium as neither cellular event proceeded in its absence. Cholinergic enhancement of the immunologic secretion of ß-glucuronidase from neutrophils by acetylcholine was associated with a concomitant accumulation of cyclic GMP. These actions of acetylcholine on neutrophils did not proceed in the absence of extracellular calcium. Whereas the concentrations of cyclic GMP in neutrophils were elevated by both immune reactants and a combination of the latter and acetylcholine, cyclic AMP levels remained unaltered. Thus, cyclic GMP, but not cyclic AMP, was associated with the immunologic and pharmacologic discharge of lysosomal enzymes from neutrophils. Contrariwise, cyclic AMP, but not cyclic GMP, was associated with inhibition of lysosomal enzyme release. For example, dibutyryl cyclic AMP and epinephrine inhibited the release of ß-glucuronidase from neutrophils that was elicited by each of the immune reactants tested. Moreover, cyclic AMP levels in the cells were elevated markedly in every instance that enzyme discharge was inhibited by epinephrine. Epinephrine did not alter the neutrophil concentrations of cyclic GMP at times when those of cyclic AMP were elevated. The data in this report constitute partial evidence that the immunologic discharge of lysosomal enzymes from human neutrophils is mediated or signaled by intracellular cyclic GMP and that calcium is linked to this stimulation of enzyme secretion.

CORRELATION OF CYCLIC AMP AND CYCLIC GMP ACCUMULATION AND STEROIDOGENESIS DURING STIMULATION OF BOVINE LUTEAL CELLS WITH LUTEINIZING HORMONE

1980 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
W. Y. LING ◽  
M. T. WILLIAMS ◽  
J. M. MARSH
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Direct Evidence ◽  
Significant Rise ◽  
Maximum Increase ◽  
Luteal Cells ◽  
Bovine Corpus Luteum ◽  
Intermediary Role ◽  
The Relationship ◽  
Stimulation Of

The relationship between LH-induced steroidogenesis and the production of cyclic AMP and cyclic GMP was studied as a function of LH dose and time in isolated luteal cells from pregnant cows. Submaximal steroidogenic concentrations of LH caused a transient but significant rise in cyclic AMP that peaked after incubation for 5 min. A consequent rise in progesterone occurred at 30 min even though cyclic AMP had returned to the basal level at that time. Higher steroidogenic doses of LH elicited a maximum increase of cyclic AMP at 5 min and this was sustained for up to 1 h; the related progesterone production was significantly raised at 15 min and reached a maximum plateau at 30 min. The corresponding levels of cyclic GMP did not appear to be altered by any of the LH concentrations used. The present study has provided direct evidence that even at very low doses of LH, cyclic AMP plays an intermediary role in the stimulation of steroidogenesis in a mixed population of cells isolated from the bovine corpus luteum. Cyclic GMP, on the other hand, did not appear to play a role in the action of LH on the same population of luteal cells.

Studies on Locust Rectum: I. Stimulants of Electrogenic Ion Transport

1980 ◽  
Vol 86 (1) ◽  
pp. 211-223
Author(s):  
J. H. SPRING ◽  
J. E. PHILLIPS
Keyword(s):  
Steady State ◽  
Cyclic Amp ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Lag Time ◽  
Camp Concentration ◽  
Maximum Increase ◽  
Electrogenic Ion Transport ◽  
The Relationship ◽  
Stimulation Of

1. Homogenates of whole corpora cardiaca (CC) cause increases in the short-circuit current (Isc) and transepithelial electropotential difference (PD) across locust recta of 3-fold and 1.7-fold respectively, in comparison with the values for unstimulated steady-state recta. Maximum stimulation restores rectal ISC and PD to levels observed immediately after removing this organ from animals. 2. Cyclic-AMP causes a similar maximum increase in ISC and PD; however, the response exhibits a much shorter lag time and a faster rate of rise than is observed for stimulation with CC. 3. The addition of CC to the haemocoel side of everted rectal sacs caused whole tissue levels of cAMP in this organ to increase 3-fold. 4. The relationship between the logarithm of CC or cAMP concentration and the increase in ISC is linear, and the decline in ΔISC with time is also dosedependent. 5. Small maximum increases in ISC are caused by homogenates of ventral ganglia, whole brain and rectal tissue, but the concentration of the stimulatory activity in these locust tissues is clearly three orders of magnitude lower than in CC. 6. Inhibitors of HCO3—/H+ and Cl− transport in vertebrate systems, acetazolamide and thiocyanate, do not inhibit the stimulation of recta by CC or cAMP.

Actions of histamine, secretin, and PGE2 on cyclic AMP production by isolated canine fundic mucosal cells.

1979 ◽  
Vol 237 (5) ◽  
pp. E437
Author(s):  
A Wollin ◽  
A H Soll ◽  
I M Samloff
Keyword(s):  
Cyclic Amp ◽  
Parietal Cell ◽  
Cell Type ◽  
Gastric Mucosal Cells ◽  
Cell Content ◽  
Histamine Stimulation ◽  
Mucosal Cells ◽  
Single Cell Type ◽  
Cell Fractions ◽  
Stimulation Of

Cyclic AMP production was studied in isolated canine fundic gastric mucosal cells. Histamine, prostaglandin E2 (PGE2), and secretin increased cyclic AMP production by unenriched mucosal cells. In separated cell fractions, histamine stimulation of cyclic AMP production correlated with the parietal cell content of the fractions. Secretin in concentrations above 1 nM stimulated cyclic AMP production, and this effect correlated with the pepsinogen content of the separated cell fractions. At concentrations above 1 microM, PGE2 stimulated cyclic AMP production; this effect was found in all separated cell fractions and was not associated with any of the available cell markers. PGE2 stimulation of cyclic AMP production was, however, negatively correlated with the parietal cell content. Thus, histamine stimulated cyclic AMP production by parietal cells and secretin stimulated production of cyclic AMP by chief cells. PGE2 stimulation of cyclic AMP production could not be localized to a single cell type but occurred primarily in nonparietal cells.

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