Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human peripheral blood mononuclear leukocytes were labeled with myo-[3H]inositol and stimulated by platelet-activating factor (PAF). PAF-induced phosphatidylinositol hydrolysis and inositol-1,4,5-trisphosphate (IP3) formation in a dose-dependent manner. The response was very rapid and transient and parallels the time course of PAF-induced calcium mobilization in the same cells. However, the doses of PAF for inducing IP3 formation were much higher than those for calcium mobilization. PAF-induced IP3 formation was inhibited by PAF receptor antagonist, L-659, 989, but was not altered by either pertussis toxin or cholera toxin. These data suggest that PAF receptor in human peripheral blood mononuclear leukocytes may be coupled through a pertussis toxin-insensitive guanine nucleotide binding protein to a phosphoinositide-specific phospholipase C.
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PMID:Platelet-activating factor (PAF) stimulates phosphatidylinositol hydrolysis in human peripheral blood mononuclear leukocytes. 255 57

Pertussis toxin was used to examine the functional linkage between somatostatin and acid secretion and the mode of action of somatostatin at the cellular level in the isolated luminally perfused mouse stomach. Pretreatment of the stomach with pertussis toxin (125-1,250 ng/ml) for 60 min 1) caused a significant twofold increase in histamine-stimulated acid secretion (from 42 +/- 7 to 82 +/- 12 nmol/min; P less than 0.01) but not pentagastrin-stimulated secretion and 2) blocked the inhibitory effect of somatostatin on basal and histamine-stimulated acid secretion but not on pentagastrin-stimulated acid secretion. The ability of pertussis toxin to reverse selectively the inhibitory effect of somatostatin on histamine-stimulated acid secretion is consistent with the ability of pertussis toxin to inactivate a guanine nucleotide binding protein, which couples somatostatin receptors to inhibition of adenylate cyclase; histamine, but not gastrin, stimulates acid secretion via activation of adenylate cyclase. Secretagogue-stimulated acid secretion was accompanied by a parallel increase in somatostatin secretion that is largely determined by luminal acidity. The augmentation of histamine-stimulated acid secretion after treatment with pertussis toxin implied that the concomitant increase in somatostatin secretion is coupled to acid secretion and acts to attenuate it. The results confirm the role of gastric somatostatin as a paracrine regulator of acid secretion.
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PMID:Linkage between somatostatin and acid secretion: evidence from use of pertussis toxin. 256 28

Radioligand binding and functional assays were employed to demonstrate the existence of somatostatin receptors in the murine neuroblastoma clone N1E-115. Saturation experiments with [125I][Tyr11]somatostatin-14 indicated the presence of a single class of binding sites in membranes prepared from N1E-115 cells (Kd = 83 pM; Bmax = 21,000 receptors/cell). Somatostatin-14, somatostatin-28 and L363586 (cyclo(N-Me-ALA-TYR-D-TRP-LYS-VAL-PHE] all displaced the 125I-ligand monophasically in N1E-115 cells (Ki values were 28, 82 and 34 pM, respectively), which contrasted with the binding heterogeneity apparent with L363586 in rat brain membranes. The binding of [125I][Tyr11]somatostatin-14 was reduced by GppNHp, indicating that N1E-115 somatostatin receptors interacted with guanine nucleotide binding protein(s). Somatostatin agonists decreased by 30-50% the levels of [3H]cyclic AMP induced in intact cells by forskolin, prostaglandin E1, or vasoactive intestinal polypeptide. The EC50 values for inhibition of the [3H]cyclic AMP response to PGE1 by L363586, somatostatin-14, and somatostatin-28 were 0.24, 0.63 and 1.0 nM, respectively. Pertussis toxin treatment of N1E-115 cells reduced both binding to the receptor and the functional response to somatostatin-14. These data suggest that a single class of somatostatin receptors in N1E-115 cells are linked to the inhibition of adenylate cyclase through a Gi protein.
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PMID:Biochemical evidence for somatostatin receptors in murine neuroblastoma clone N1E-115. 256 62

Somatostatin receptors of plasma membranes from beta cells of hamster insulinoma were covalently labelled with 125I-[Leu8,D-Trp22,Tyr25]somatostatin-28 (125I-somatostatin-28) and solubilized with the non-denaturing detergent Triton X-100. Analysis by SDS/PAGE and autoradiography revealed three specific 125I-somatostatin-28 receptor complexes with similar molecular masses (228 kDa, 128 kDa and 45 kDa) to those previously identified [Cotroneo, P., Marie, J.-C. & Rosselin, G. (1988) Eur. J. Biochem. 174, 219-224]. The major labelled complex (128 kDa) was adsorbed to a wheat-germ-agglutinin agarose column and eluted by N-acetylglucosamine. Also, the binding of 125I-somatostatin-28 to plasma membranes was specifically inhibited by the GTP analog, guanosine-5'-O-(3-thiotriphosphate) (GTP[S]) in a dose-dependent manner. Furthermore, when somatostatin-28 receptors were solubilized by Triton X-100 as a reversible complex with 125I-somatostatin-28, GTP[S] specifically dissociated the bound ligand to a larger extent from the soluble receptors than from the plasma-membrane-embedded receptors, the radioactivity remaining bound after 15 min at 37 degrees C being 30% and 83% respectively. After pertussis-toxin-induced [32P]ADP-ribosylation of pancreatic membranes, a 41-kDa [32P]ADP-ribose-labelled inhibitory guanine nucleotide binding protein coeluted with the 128-kDa and 45-kDa receptor complexes. The labelling of both receptor proteins was sensitive to GTP[S]. The labelling of the 228-kDa band was inconsistent. These results support the conclusion that beta cell somatostatin receptors can be solubilized as proteins of 128 kDa and 45 kDa. The major labeled species corresponds to the 128-kDa band and is a glycoprotein. The pancreatic membrane contains a 41-kDa GTP-binding protein that can complex with somatostatin receptors.
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PMID:Solubilization of somatostatin receptors in hamster pancreatic beta cells. Characterization as a glycoprotein interacting with a GTP-binding protein. 257 68

We undertook these studies to examine the mechanisms by which carbachol inhibits somatostatin release. For these studies, we utilized cultured D-cells isolated from the canine gastric fundus. Carbachol inhibited somatostatin release induced by both pentagastrin and 12-O-tetradecanoyl-phorbol-13-acetate but did not alter the redistribution of protein kinase C induced by these agents. In contrast, carbachol diminished the increase in D-cell cytosolic free calcium levels ([Ca2+]i) induced by pentagastrin, and this effect was no longer evident after pretreatment of D-cells with pertussis toxin. Although carbachol by itself had no effect on [Ca2+]i, after pretreatment of D-cells with pertussis toxin, carbachol both enhanced [Ca2+]i and stimulated somatostatin release. These data indicate that carbachol activates signals in D-cells that result in both increase and decrease in [Ca2+]i. The latter effect, which appears to be mediated via a pertussis toxin-sensitive guanine nucleotide binding protein, may be one mechanism responsible for cholinergic inhibition of somatostatin release.
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PMID:Carbachol inhibits stimulant-induced increases in fundic D-cell cytosolic Ca2+ concentration. 276 14

Cellular proliferation of rat glioma C6 BU1 cells in tissue culture is dependent on the presence of either calf or foetal-calf serum in the medium. Foetal-calf serum stimulated a high-affinity GTPase in membranes derived from C6 BU1 cells. Pretreatment of the cells with pertussis toxin decreased the high-affinity GTPase activity substantially, and attenuated the foetal-calf-serum-stimulated increase in this GTPase activity. Cholera toxin, in contrast, did not modulate the response to foetal-calf serum. Foetal-calf serum did not inhibit adenylate cyclase activity in membranes of these cells, indicating that the G-protein that was stimulated by foetal-calf serum was not Gi (the inhibitory one). Although the nature of the specific component of foetal-calf serum responsible for this pertussis-toxin-sensitive receptor-mediated stimulation of high-affinity GTPase activity has not been identified, it was mimicked neither by bombesin, which can stimulate inositol phospholipid turnover via a guanine nucleotide binding protein, nor by platelet-derived growth factor, which is present in substantial concentrations in foetal-calf serum. This report represents the first demonstration of a pertussis-toxin-substrate-mediated response in this cell line and provides further evidence that G-proteins other than Gi can be functionally inactivated by pertussis toxin.
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PMID:Foetal-calf serum stimulates a pertussis-toxin-sensitive high-affinity GTPase activity in rat glioma C6 BU1 cells. 282 23

In this study the mechanisms involved in alpha 1-adrenergic receptor-mediated Ca2+ mobilization at the level of the plasma membrane were investigated. Stimulation of 45Ca2+ efflux from saponin-permeabilized DDT1 MF-2 cells was observed with the addition of either the alpha 1-adrenergic agonist phenylephrine and guanosine-5'-triphosphate or the nonhydrolyzable guanine nucleotide guanylyl-imidodiphosphate. In the presence of [32P]NAD, pertussis toxin was found to catalyze ADP-ribosylation of a Mr = 40,500 (n = 8) peptide in membranes prepared from DDT1 MF-2 cells, possibly the alpha-subunit of Ni. However, stimulation of unidirectional 45Ca2+ efflux by phenylephrine was not affected by previous treatment of cells with 100 ng/ml pertussis toxin. These data suggest that the putative guanine nucleotide-binding protein which couples the alpha 1-adrenergic receptor to Ca2+ mobilization in DDT1 MF-2 cells is not a pertussis toxin substrate and may possibly be an additional member of the guanine nucleotide binding protein family.
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PMID:Role of a guanine nucleotide-binding protein in alpha 1-adrenergic receptor-mediated Ca2+ mobilization in DDT1 MF-2 cells. 282 74

The ability of propionic acid to elicit an increase in the level of cytoplasmic free calcium in human neutrophils was examined in detail. Propionic acid induced a rapid and dose-dependent mobilization of calcium that relied on both internal and external sources of calcium. The effects of propionic acid on the mobilization of calcium were inhibited by pertussis toxin, but not cholera toxin, implicating a guanine nucleotide binding protein. Furthermore, preincubation of the neutrophils with phorbol 12-myristate 13-acetate resulted in a decreased mobilization of calcium. This inhibitory activity of phorbol myristate acetate was antagonized by the protein kinase C inhibitor H-7. Preincubation of the cells with the synthetic chemotactic factor fMet-Leu-Phe caused a reduction in the magnitude of the calcium transient elicited by propionic acid. However, the calcium response to propionic acid was not affected by antagonists of fMet-Leu-Phe and platelet-activating factor binding or by an inhibitor of leukotriene synthesis. Propionic acid did not elicit a mobilization of calcium in monocytes, platelets, lymphocytes, or undifferentiated HL-60 cells. However, the treatment of the HL-60 cells with dimethylsulfoxide resulted in the appearance of a calcium response to propionic acid. The potential physiological significance of these findings are discussed.
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PMID:Propionic acid-induced calcium mobilization in human neutrophils. 284 Apr 39

A basophilic leukemic cell line from rat (RBL-1) was used to characterize leukotriene D4 (LTD4) receptor-mediated biochemical and pharmacological effects. [3H]LTD4 binding to the plasma membrane enriched preparation was stereo-selective, specific and saturable. Sodium ions and guanine nucleotides specifically regulated [3H]LTD4 binding to the membrane receptors. Leukotriene E4 (LTE4) and high affinity specific antagonists bound to the receptor with a rank-order potency equivalent to that for the LTD4 receptors in guinea pig lung. In the [3]myoinositol labeled RBL-1 cells, LTD4 and LTE4 induced a rapid hydrolysis of [3H]phosphoinositides. The biosynthesis of the [3H]inositol-trisphosphate was rapid and was detectable at 15-sec poststimulation. The biosynthesis of [3H]inositol-monophosphate was stereo-selective and specific and was inhibited specifically by receptor antagonists. In fura-2 loaded RBL-1 cells, LTD4 and LTE4 induced a transient intracellular Ca++ mobilization. Agonist-induced Ca++ mobilization was specific and stereo-selective and was inhibited by specific receptor antagonists. The most (greater than 85%) LTD4-induced immediate response of Ca++ mobilization was from intracellular sources, whereas a small amount (less than 15%) was derived from the extracellular milieu. Both components were stimulated by receptor agonists and inhibited by the receptor antagonists, suggesting that they were regulated by the LTD4 membrane receptors. In addition, the results also suggested that a guanine nucleotide binding protein, insensitive to islet activating protein from Bordetella pertussis (not Gi or Go), was involved in the signal transduction mechanisms for LTD4 receptors in RBL-1 cells. These results suggested that the plasma membrane enriched LTD4 receptor was coupled via an islet activating protein insensitive G protein to a phosphoinositide specific phospholipase C. Agonist binding to the receptor could activate phospholipase C and resulted in phosphoinositide hydrolysis. Diacylglycerol and inositol trisphosphate could function as intracellular messengers that trigger or contribute to calcium mobilization in RBL-1 cells.
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PMID:Leukotriene D4 receptor-mediated phosphoinositol hydrolysis and calcium mobilization in rat basophilic leukemic cells. 284 29

Volatile anesthetics have been shown to decrease hormone-induced adenosine cyclic monophosphate (cAMP) formation and to increase guanosine cyclic monophosphate (cGMP) content in mouse ventricular myocardium. Hormone-induced inhibition of adenylate cyclase, the enzyme that synthesizes cAMP, and the cGMP response to alpha adrenergic agonists are mediated by a guanine nucleotide binding protein (N) sensitive to pertussis toxin. To evaluate the involvement of N proteins in the action of halothane on cyclic nucleotides in the heart, mice were pretreated with pertussis toxin, 50 micrograms/kg, ip, 72 h prior to exposure to halothane, 1.2 vol%. Pretreatment with the toxin decreased the cGMP response to halothane by 65% but was without effect on the decrease in myocardial cAMP induced by the anesthetic. The results indicate that a functionally active pertussis toxin-sensitive N protein is involved in the cGMP response to halothane, but not in the cAMP response.
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PMID:Halothane interaction with guanine nucleotide binding proteins in mouse heart. 284 25


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