The in vitro effect of a thymic epithelial culture supernatant on mixed lymphocyte reactivity and intracellular cAMP levels of thymocytes and on antibody production to SRBC by nu/nu spleen cells

Experiments reported here were performed to understand the mechanism by which THF increases the immunocompetence of spleen cells from NTx mice. Dibutyryl cAMP or substances which increase intracellular levels of cAMP in lymphocytes such as Poly(A:U), theophylline, or PGE2 were shown to mimic the effect of THF and confer reactivity in an in vitro GvH response to spleen cells from NTx mice. Flufenamic acid, an antagonist to PGE2, was shown to inhibit the induction of competence by this substance. It was found that THF induces competence by activating membranal adenyl cyclase which leads to a rise in intracellular cAMP in thymus-derived cells only. These biochemical changes occur before antigenic stimulation and are unrelated to antigenic challenge. These findings indicate that THF exerts its effect via cAMP and are in agreement with the concepts which permit to classify THF as a thymus hormone.

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Chloroquine stimulates absorption and inhibits secretion of ileal water and electrolytes

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1982.243.2.g117 ◽

1982 ◽

Vol 243 (2) ◽

pp. G117-G126

Author(s):

R. Fogel ◽

G. W. Sharp ◽

M. Donowitz

Keyword(s):

Cholera Toxin ◽

Calcium Content ◽

Intracellular Camp ◽

Rabbit Ileum ◽

Camp Content ◽

Serosal Surface ◽

Ileal Absorption ◽

Camp Levels

The effects of chloroquine diphosphate, a drug with "'membrane-stabilizing" properties, were studied on basal ileal absorption and on ileal secretion induced by increased intracellular cAMP levels and calcium (serotonin). The studies were performed on rat (in vivo) and rabbit ileum (in vitro). Intraluminal chloroquine (10(-4) M) reversed cholera toxin- and theophylline-induced secretion in rat ileum but did not alter the cholera toxin- and theophylline-induced increases in cAMP content. Addition of chloroquine (10(-4) M) to the mucosal surface of rabbit ileum did not alter basal active electrolyte transport or the serotonin-induced decreased Na and Cl absorption but inhibited the theophylline-induced C1 secretion. Addition of chloroquine (10(-4)) M) to the serosal surface stimulated net Na and Cl absorption. This effect may involve intracellular calcium. Chloroquine increased the rabbit ileal calcium content and decreased 45Ca2+ influx from the serosal surface. Both the mucosal and serosal effects of chloroquine described led to a net increase in absorptive function of the intestine and should prove useful in developing treatment of diarrheal diseases.

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In vivo and in vitro Effect of Anti-lymphocytic IgG on Sensitized Spleen Cells

Nature ◽

10.1038/217261a0 ◽

1968 ◽

Vol 217 (5125) ◽

pp. 261-262 ◽

Cited By ~ 2

Author(s):

KEITH JAMES

Keyword(s):

Spleen Cells ◽

Vitro Effect

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Ginseng Total Saponin Enhances the Phagocytic Capacity of Canine Peripheral Blood Phagocytes in Vitro

The American Journal of Chinese Medicine ◽

10.1142/s0192415x08005801 ◽

2008 ◽

Vol 36 (02) ◽

pp. 329-341 ◽

Cited By ~ 13

Author(s):

K. A. Kang ◽

J. H. Kang ◽

M. P. Yang

Keyword(s):

Peripheral Blood ◽

Mononuclear Cells ◽

Culture Supernatant ◽

Polymorphonuclear Cells ◽

Phagocytic Capacity ◽

Total Saponin ◽

Tnf Α ◽

Vitro Effect ◽

Ginseng Total Saponin

The clinical and pharmacological activities of ginseng are known to modulate immune function, metabolic processes and neuro-endocrine system activities. Ginseng saponins are the principle active ingredients in the formation of immune stimulating complexes. The objective of this study was to evaluate the in vitro effect of ginseng total saponin (GTS) on the phagocytic capacity of canine peripheral blood phagocytes. GTS itself did not cause any direct effect on the phagocytic capacity of peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) but not peripheral blood monocytes. However, the phagocytic capacity of PMN and monocytes, but not PBMC, was enhanced by the culture supernatant from PBMC treated with GTS. The phagocytic capacity of PMN and monocytes was also increased by treatment with recombinant canine (rc) tumor necrosis factor (TNF)-α. The ability of the culture supernatant from GTS-treated PBMC to stimulate the phagocytic capacity of phagocytes was inhibited by addition of anti-rc TNF-α polyclonal antibody (pAb) prior to the culture. The amount of TNF-α in the culture supernatant from PBMC was shown to increase upon treatment of GTS as compared with that of vehicle-treated PBMC culture supernatant. These results suggest that GTS has an immunoenhancing effect on the phagocytic capacity of canine peripheral blood phagocytes, which is mainly mediated by TNF-α released from GTS-stimulated PBMC.

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In Vitro Effect of Acetaldehyde on Cell-Mediated Cytotoxicity by Murine Spleen Cells

Alcoholism Clinical and Experimental Research ◽

10.1111/j.1530-0277.1989.tb00418.x ◽

1989 ◽

Vol 13 (6) ◽

pp. 766-771 ◽

Cited By ~ 4

Author(s):

Amrik S. Walia ◽

Kenneth M. Pruitt ◽

Dirck L. Dillehay ◽

G. M. Marshall ◽

E. W. Lamon

Keyword(s):

Spleen Cells ◽

Murine Spleen ◽

Vitro Effect

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Ammonia promotes accumulation of intracellular cAMP in differentiating amoebae of Dictyostelium discoideum

Development ◽

10.1242/dev.109.3.715 ◽

1990 ◽

Vol 109 (3) ◽

pp. 715-722

Author(s):

B.B. Riley ◽

S.L. Barclay

Keyword(s):

Dictyostelium Discoideum ◽

Active Species ◽

Spore Formation ◽

Intracellular Camp ◽

Simultaneous Exposure ◽

High Ph ◽

Camp Hydrolysis ◽

Extracellular Camp ◽

Camp Levels

We used sporogenous mutants of Dictyostelium discoideum to investigate the mechanism(s) by which exogenous NH4Cl and high ambient pH promote spore formation during in vitro differentiation. The level of NH4Cl required to optimize spore formation is correlated inversely with pH, indicating that NH3 rather than NH4+ is the active species. The spore-promoting activity of high ambient pH (without exogenous NH4Cl) was eliminated by the addition of an NH3-scavenging cocktail, suggesting that high pH promotes spore differentiation by increasing the ratio of NH3:NH4+ secreted into the medium by developing cells. High ammonia levels and high pH stimulated precocious accumulation of intracellular cAMP in both sporogenous and wild-type cells. In both treatments, peak cAMP levels equaled or exceeded control levels and were maintained for longer periods than in control cells. In contrast, ammonia strongly inhibited accumulation of extracellular cAMP without increasing the rate of extracellular cAMP hydrolysis, indicating that ammonia promotes accumulation of intracellular cAMP by inhibiting cAMP secretion. These results are consistent with previous observations that factors that raise intracellular cAMP levels increase spore formation. Lowering intracellular cAMP levels with caffeine or progesterone inhibited spore formation, but simultaneous exposure to these drugs and optimal concentrations of NH4Cl restored both cAMP accumulation and spore formation to normal levels. These data suggest that ammonia, which is a natural Dictyostelium morphogen, favors spore formation by promoting accumulation or maintenance of high intracellular cAMP levels.

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Modulation of human neutrophil function in vitro by gastrin

Journal of Endocrinology ◽

10.1677/joe.0.1530475 ◽

1997 ◽

Vol 153 (3) ◽

pp. 475-483 ◽

Cited By ~ 17

Author(s):

M De la Fuente ◽

M Carrasco ◽

A Hernanz

Keyword(s):

Superoxide Anion ◽

Latex Bead ◽

Human Neutrophils ◽

Intracellular Camp ◽

Maximal Effect ◽

Superoxide Anion Production ◽

Phagocytic Process ◽

Anion Production ◽

Camp Levels

Abstract We have studied the effects in vitro of gastrin-17 and gastrin-34, at concentrations from 10−14 m to 10−6 m, on several of the functions of peripheral blood human neutrophils, i.e. adherence to substrate, mobility (spontaneous and directed by a chemical gradient or chemotaxis), ingestion of inert particles (latex beads) and cells (Candida albicans) and superoxide anion production. Both gastrins inhibited several steps of the phagocytic process of human neutrophils, such as mobility and ingestion. By contrast, these peptides increased adherence and had no effect on superoxide anion production. In general, these effects were significant at peptide concentrations between 10−12 m and 10−8 m with a maximal effect at 10−10 m. In addition, gastrin peptides induced a significant increase in intracellular cAMP levels at 30, 60 and 120 s. Moreover, the inhibitory effect of gastrin-17 on the ingestion capacity of neutrophils (latex bead phagocytosis) was similar to that obtained with EGTA, a well-known extracellular calcium chelating compound. Gastrin-17 was found to inhibit completely the stimulation of latex bead phagocytosis in neutrophils caused by the calcium ionophore A23187. These results suggest that gastrin is a negative modulator of the phagocytic process of human neutrophils, and that this effect might involve an increase in intracellular cAMP levels and a decrease in calcium entry into the cells. Journal of Endocrinology (1997) 153, 475–483

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Aminophylline and progesterone prevent inflammation-induced preterm parturition in the mouse†

Biology of Reproduction ◽

10.1093/biolre/ioz112 ◽

2019 ◽

Vol 101 (4) ◽

pp. 813-822 ◽

Cited By ~ 4

Author(s):

Bronwen R Herbert ◽

Danijela Markovic ◽

Ektoras Georgiou ◽

Pei F Lai ◽

Natasha Singh ◽

...

Keyword(s):

Ex Vivo ◽

Phosphodiesterase Inhibitor ◽

Adenosine Monophosphate ◽

Cytokine Gene Expression ◽

Intracellular Camp ◽

Myometrial Cells ◽

Anti Inflammatory ◽

Camp Levels

Abstract Although progesterone (P4) supplementation is the most widely used therapy for the prevention of preterm labor (PTL), reports of its clinical efficacy have been conflicting. We have previously shown that the anti-inflammatory effects of P4 can be enhanced by increasing intracellular cyclic adenosine monophosphate (cAMP) levels in primary human myometrial cells. Here, we have examined whether adding aminophylline (Am), a non-specific phosphodiesterase inhibitor that increases intracellular cAMP levels, to P4 might improve its efficacy using in vivo and in vitro models of PTL. In a mouse model of lipopolysaccharide (LPS)-induced PTL, we found that the combination of P4 and Am delayed the onset of LPS-induced PTL, while the same dose of P4 and Am alone had no effect. Pup survival was not improved by either agent alone or in combination. Myometrial prolabor and inflammatory cytokine gene expression was reduced, but the reduction was similar in P4 and P4/Am treated mice. There was no effect of the combination of P4 and Am on an ex vivo assessment of myometrial contractility. In human myometrial cells and myometrial tissue explants, we found that the combination had marked anti-inflammatory effects, reducing cytokine and COX-2 mRNA and protein levels to a greater extent than either agent alone. These data suggest that the combination of P4 and Am has a more potent anti-inflammatory effect than either agent alone and may be an effective combination in women at high-risk of PTL.

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