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)

Subtypes of P2Y receptors are well characterized with respect to their agonist profile but little is known about differences in their intracellular signalling properties. When expressed in Xenopus oocytes, both P2Y2 and P2Y6 receptors effectively couple to endogenous Ca2+-dependent Cl--channels. However, only P2Y2 receptors increased currents mediated by inward-rectifier K+ channels of the Kir3.0 subfamily. This increase in Kir-current was sensitive to pertussis toxin, while activation of Ca2+-dependent Cl--channels was not. In contrast, suramin, a P2 receptor antagonist, inhibited activation of both channels. These observations suggest that, in contrast to P2Y6, P2Y2 receptors couple to two different classes of G proteins.
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PMID:P2Y receptor subtypes differentially couple to inwardly-rectifying potassium channels. 977 2

The effect of adenosine triphosphate (ATP) on the intracellular Ca2+ concentration ([Ca2+]i) of cultured neurohypophysial astrocytes (pituicytes) was studied by fluorescence videomicroscopy. ATP evoked a [Ca2+]i increase, which was dose dependent in the 2.5-50 microM range (EC50=4.3 microM). The ATP-evoked [Ca2+]i rise was not modified during the first minute following the removal of external Ca2+. Application of 500 nM thapsigargin inhibited the ATP-dependent [Ca2+]i increase. Caffeine (10 mM) and ryanodine (1 microM) did not affect the ATP-induced [Ca2+]i rise. The pituicytes responded to various P2 purinoceptor agonists with the following order of potency: ATP=ATP[gamma-S]=2-MeSATP>/=ADP, where ATP[gamma-S] is adenosine 5'-O-(3-thiotriphosphate) and 2-MeSATP is 2-methylthio-adenosine-5'-triphosphate. Adenosine, AMP, alpha, beta-methylene adenosine-5'-triphosphate (alpha,beta-MeATP), beta, gamma methylene adenosine-5'-triphosphate (beta,gamma-MeATP) and uridine 5'-triphosphate (UTP) were ineffective. The P2 purinoceptor antagonists blocked the ATP-evoked [Ca2+]i increase with the following selectivity: RB-2>suramin>PPADS, where RB-2 is Reactive Blue 2 and PPADS is pyridoxal-phosphate-6-azophenyl-2', 4'-disulphonic acid. The ATP-evoked [Ca2+]i increase was substantially blocked by pertussis toxin treatment, suggesting that it might be mediated by a pertussis-toxin-sensitive G protein. The phospholipase C (PLC) inhibitor U-73122 (0.5 microM) abolished the ATP-evoked [Ca2+]i rise, whereas its inactive stereoisomer U-73343 (0.5 microM) remained ineffective. Our results indicate that, in rat cultured pituicytes, ATP stimulation induces an increase in [Ca2+]i due to PLC-mediated release from intracellular stores through activation of a pertussis-toxin-sensitive, G-protein-linked P2Y receptor.
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PMID:ATP acting on P2Y receptors triggers calcium mobilization in primary cultures of rat neurohypophysial astrocytes (pituicytes). 1008 53

1. The P2Y6 receptor is a uridine nucleotide-specific G protein-linked receptor previously reported to stimulate the phosphoinositide (PI) pathway. We have investigated its effect in neurones, by micro-injecting its cRNA into dissociated rat sympathetic neurones and recording responses of N-type Ca2+ (I(Ca(N))) and M-type K+ (I(K(M))) currents. 2. In P2Y6 cRNA-injected neurones, UDP or UTP produced a voltage-dependent inhibition of I(Ca(N)) by approximately 53% in whole-cell (disrupted-patch) mode and by 73% in perforated-patch mode; no inhibition occurred in control cells. Mean IC50 values (whole-cell) were: UDP, 5.9+/-0.3 nM; UTP, 20+/-1 nM. ATP and ADP (1 microM) had no significant effect. Pertussis toxin (PTX) substantially (approximately 60%) reduced UTP-mediated inhibition in disrupted patch mode but not in perforated-patch mode. 3. Uridine nucleotides also inhibited I(K(M)) in P2Y6 cRNA-injected cells (by up to 71% at 10 microM UTP; perforated-patch). Mean IC50 values were: UDP, 30+/-3 nM; UTP, 115+/-12 nM. ATP (10 microM) again had no effect. No significant inhibition occurred in control cells. Inhibition was PTX-resistant. 4. Thus, the P2Y6 receptor, like the P2Y2 subtype studied in this system, couples to both of these two neuronal ion channels through at least two different G proteins. However, the P2Y6 receptor displays a much higher sensitivity to its agonists than the P2Y2 receptor in this expression system and higher than previously reported using other expression methods. The very high sensitivity to both UDP and UTP suggests that it might be preferentially activated by any locally released uridine nucleotides.
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PMID:Dual coupling of heterologously-expressed rat P2Y6 nucleotide receptors to N-type Ca2+ and M-type K+ currents in rat sympathetic neurones. 1019 82

1. Northern blotting experiments have been performed with RNA extracted from several cell lines derived from the human lung in order to detect P2Y1, P2Y2, P2Y4 and P2Y6 mRNA. We have investigated the 1HAEo- and 16HBE14o- epithelial cell lines derived from the airway epithelium, the A549 cell line displaying properties of type II alveolar epithelial cells, the CALU-3 serous cells, the 6CFSMEo- submucosal cells and the HASMSC1 airway smooth muscle cells. We have also evaluated one pancreatic epithelial cell line called CFPAC-1. These experiments revealed that P2Y2 and P2Y6 mRNA are co-expressed in the IHAEo-, 16HBE14o- and A549 epithelial cell lines. The CFPAC-1 pancreatic cell line was strongly positive for the P2Y2 receptor. No signal was obtained for the P2Y1 and P2Y4 receptors. 2. We have then performed RT-PCR experiments with specific oligonucleotides of these last two P2Y receptors with the RNA used for the Northern blotting experiments. P2Y4 mRNA was detected in five cell lines: 1HAEo-, 16HBE14o-, 6CFSMEo-, HASMSC1 and CFPAC-1. P2Y1 mRNA was only detected in the CALU-3 cell line. 3. Inositol trisphosphates assays have identified a response typical of the P2Y2 receptor in the 1HAEo- and the 16HBE14o- airway epithelial cell lines which co-express P2Y2 and P2Y6 mRNA. By contrast, the 6CFSMEo- submucosal cells expressed a UTP-specific response which displayed pharmacological characteristics compatible with the human P2Y4 receptor: in particular, there was no response to UDP or ATP and the UTP effect was totally inhibited by pertussis toxin.
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PMID:Expression of P2Y receptors in cell lines derived from the human lung. 1038 59

Experiments were performed to characterize the P2 purinoceptor subtype responsible for cytoplasmic calcium mobilization in cells from the initial part of rabbit distal convoluted tubule (DCT). Free calcium concentration was measured in a DCT cell line (DC1) with the probe fura 2. Both ATP and UTP increased cytosolic Ca(2+) concentration ([Ca(2+)](i); EC(50) 3 and 6 microM, respectively). The order of potency for nucleotide analogs was ATP = UTP > adenosine 5'-O-[thiotriphosphate] >> ADP > UDP, which is consistent with the pharmacology of the P2Y2 receptor subtype. The increased [Ca(2+)](i) responses to ATP and UTP were strongly inhibited by suramin. Pretreatment of cells with pertussis toxin (PTX) attenuated the action of both nucleotides. Inhibition of phospholipase C with U-73122 totally blocked the [Ca(2+)](i) response to ATP. Thus ATP- and UTP-stimulated [Ca(2+)](i) mobilization in DC1 cells appears to be mediated via the activation of P2Y2 purinoceptors coupled to a G protein mechanism that is partially sensitive to PTX. Calcium flux measurements showed that lanthanum- and nifedipine-sensitive calcium channels are involved in the [Ca(2+)](i) response to ATP.
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PMID:Extracellular ATP increases [CA(2+)](i) in distal tubule cells. I. Evidence for a P2Y2 purinoceptor. 1089 91

1. The mobilization of Ca2+ by purinoceptor activation and the relative contributions of intra- and extracellular sources of Ca2+ were investigated using microfluorimetric measurements of fura-2 loaded in cultured neurones from rat intracardiac ganglia. 2. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed expression of mRNA for the G protein-coupled P2Y2 and P2Y4 receptors. 3. Brief application of either 300 microM ATP or 300 microM UTP caused transient increases in [Ca2+]i of 277 +/- 22 nM and 267 +/- 39 nM, respectively. Removal of external Ca2+ did not significantly reduce these [Ca2+]i responses. 4. The order of purinoceptor agonist potency for [Ca2+]i increases was ATP = UTP > 2-MeSATP > ADP >> adenosine, consistent with the profile for P2Y2 purinoceptors. ATP- and UTP-induced rises in [Ca2+]i were completely and reversibly blocked by 10 microM PPADS (a P2 purinoceptor antagonist) and partially inhibited by 100 microM suramin (a relatively non-specific purinoceptor antagonist). 5. In the presence of the endoplasmic reticulum Ca2+-ATPase inhibitor cyclopiazonic acid (10 microM) in Ca2+-free media, the [Ca2+]i responses evoked by ATP were progressively decreased and abolished. 6. ATP- and UTP-induced [Ca2+]i rises were insensitive to pertussis toxin, caffeine (5 mM) and ryanodine (10 microM) but were significantly reduced by U-73122, a phospholipase C (PLC) inhibitor. 7. In fura-2-loaded cells, perforated patch whole-cell recordings show that ATP and UTP evoked slow outward currents at -60 mV, concomitant with the rise in [Ca2+]i, in approximately 30 % of rat intracardiac neurones. 8. In conclusion, these results suggest that in r intracardiac neurones, ATP binds to P2Y2 purinoceptors to transiently raise [Ca2+]i and activate an outward current. The signalling pathway appears to involve a PTX-insensitive G protein coupled to PLC generation of IP3 which triggers the release of Ca2+ from a ryanodine-insensitive Ca2+ store(s).
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PMID:P2Y purinoceptor activation mobilizes intracellular Ca2+ and induces a membrane current in rat intracardiac neurones. 1089 18

1. In order to investigate purinergic effects on rat ileal smooth muscle, we used alpha,beta-methylene ATP (alpha,beta-MeATP), ATP, ADP and UTP. alpha,beta-Methylene ATP and ATP were the only agonists that caused a concentration-dependent inhibition of carbachol-precontracted smooth muscle. The inhibitory effect of alpha,beta-MeATP was completely blocked by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (3 x 10(-5) mol/L), a selective antagonist of the P2X > > P2Y receptor. 2. Using reverse transcription-polymerase chain reaction we demonstrated the presence of both, P2X and P2Y receptor mRNA within the rat ileal longitudinal muscle/myenteric plexus layer preparation. 3. The alpha,beta-MeATP-induced inhibition was blocked in a concentration-dependent manner in the presence of the K+ channel blocker apamin, but was unaffected by other K+ channel blockers, such as charybdotoxin (10(-7) mol/L), 4-aminopyridine (10(-4)mol/L), glibenclamide (10(-5) mol/L) and tetraethylammonium (10(-3) mol/L). 4. The alpha,beta-MeATP-induced inhibition was unaffected by pretreatment with atropine (10(-6) mol/L), phentolamine (10(-6) mol/L), propranolol (10(-6) mol/L), nitrendipine (10(-7) mol/L), pertussis toxin (10(-6) mol/L) NG-nitro-L-arginine (3 x 10(-4) mol/L) and tetrodotoxin (10(-6) mol/L), excluding an involvement of adrenergic, cholinergic, neural, nitrinergic or G-protein involvement in purinergic-mediated inhibition. 5. In order to investigate whether the internal Ca2+ stores participated in the inhibitory effect observed, we depleted internal Ca2+ stores with cyclopiazonic acid, a specific Ca2+-ATPase inhibitor. The inhibitory effect of alpha,beta-MeATP was completely abolished after depletion of the intracellular Ca2+ stores. 6. This is in contrast with the effects seen for neurotensin, where neurotensin-induced inhibition was unchanged after depletion of intracellular Ca2+ stores, suggesting at least two different pathways of apamin-sensitive non-adrenergic, non-cholinergic inhibition in rat ileal smooth muscle. 7. According to our results, the inhibitory effect of alpha,beta-MeATP in rat ileum longitudinal smooth muscle is mediated via a P2 purinoceptor, most likely a P2X receptor, involves G-protein-independent activation of an apamin-sensitive K+ channel and requires filled intracellular Ca+ stores.
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PMID:Mechanisms of alpha,beta-methylene atp-induced inhibition in rat ileal smooth muscle: involvement of intracellular Ca2+ stores in purinergic inhibition. 1102 68

ATP has been shown to activate the phospholipase C/diacylglycerol/protein kinase C (PKC) pathway. However, little is known about the downstream signaling events. The present study was designed to examine the effect of ATP on activation of the mitogen-activated protein kinase (MAPK) signaling pathway and its physiological role in human granulosa-luteal cells. Western blot analysis, using a monoclonal antibody that detected the phosphorylated forms of extracellular signal-regulated kinase-1 and -2 (p42(mapk) and p44 (mapk), respectively), demonstrated that ATP activated MAPK in a dose- and time-dependent manner. Treatment of the cells with suramin (a P2 purinoceptor antagonist), neomycin (a phospholipase C inhibitor), staurosporin (a PKC inhibitor), or PD98059 (an MAPK/ERK kinase inhibitor) significantly attenuated the ATP-induced activation of MAPK. In contrast, ATP-induced MAPK activation was not significantly affected by pertussis toxin (a G(i) inhibitor). To examine the role of G(s) protein, the intracellular cAMP level was determined after treatment with ATP or hCG. No significant elevation of intracellular cAMP was noted after ATP treatment. To determine the role of MAPK in steroidogenesis, human granulosa-luteal cells were treated with ATP, hCG, or ATP plus hCG in the presence or absence of PD98059. RIA revealed that ATP alone did not significantly affect the basal progesterone concentration. However, hCG-induced progesterone production was reduced by ATP treatment. PD98059 reversed the inhibitory effect of ATP on hCG-induced progesterone production. To our knowledge, this is the first demonstration of ATP-induced activation of the MAPK signaling pathway in the human ovary. These results support the idea that the MAPK signaling pathway is involved in mediating ATP actions in the human ovary.
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PMID:Adenosine triphosphate activates mitogen-activated protein kinase in human granulosa-luteal cells. 1125 Sep 36

Extracellular nucleotides exert a variety of biological actions through several kinds of P2 receptors in many tissues and cell types. We found that treatment with nucleotides increases intracellular Ca2+ concentration ([Ca2+]i) in SK-N-BE(2)C human neuroblastoma cells with a following order of potency: UDP > UTP > ADP >> ATP. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that specific mRNAs coding for human P2Y1, P2Y4, and P2Y6 receptors were expressed in the cells, but Northern blot analysis revealed that P2Y6 receptors were the predominant type. Activation of protein kinase C-alpha by treatment with 1 micro m phorbol 12-myristate 13-acetate dramatically inhibited both the UDP-induced [Ca2+]i rise and inositol 1,4,5-trisphosphate (IP3) generation, whereas incubation with pertussis toxin had little effect on the responses. The UDP-induced [Ca2+]i rise and IP3 production were maintained up to 30 min after stimulation, while bradykinin-induced responses rapidly decreased to the basal level within 5 min of stimulation. Pretreatment of cells with the maximal effective concentration of UDP reduced the subsequent carbachol- or bradykinin-induced [Ca2+]i rise without inhibition of IP3 generation. Neuronal differentiation of the cells by treatment with retinoic acid for 7 days did not change the expression level of P2Y6 receptors. Taken together, the data indicate that P2Y6 receptors highly responsive to diphosphonucleotide UDP are endogenously expressed in the human neuroblastoma SK-N-BE(2)C cells and that they are involved in the modulation of other phospholipase C-coupled receptor-mediated Ca2+ mobilization by depleting the IP3-sensitive Ca2+ stores.
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PMID:Attenuation of signal flow from P2Y6 receptor by protein kinase C-alpha in SK-N-BE(2)C human neuroblastoma cells. 1271 36

This study was designed to test the hypothesis of whether activation of presynaptic P2X receptor-gated ion channels elicits noradrenaline release from central catecholaminergic terminals. ATP, alpha,beta-methylene-adenosine 5'-triphosphate (alpha,beta-methyleneATP), and ADP elicited concentration-dependent [3H]noradrenaline outflow from superfused rat hippocampal slices with the following rank order of agonist potency: alpha,beta-methyleneATP > ATP > ADP. Among P2 receptor antagonists, pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (30 microM), 4,4',4",4"'-[carbonylbis(imino-5,1,3-benzenetriyl-bis(carbonylimino))]tetrakis-1,3-benzenedisulfonic acid (100 nM), and 8,8'-[carbonybis(imino-3,1-phenylenecarbonylimino)]bis1,3,5-naphthalenetrisulphonic acid (10 microM) significantly inhibited the outflow of [3H]noradrenaline, evoked by ATP, whereas Brilliant Blue G (100 nM), 2'-deoxy-N6-methyladenosine 3',5'-bisphosphate tetraammonium (10 microM), the A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (250 nM), and the A2A receptor antagonist 3,7-dimethyl-1-propargylxanthine (250 nM) were ineffective. Pretreatment with the Gi protein inhibitor pertussis toxin (2.5 microg/ml) did not change the effect of ATP on [3H]noradrenaline outflow. In contrast, a decrease in extracellular pH from 7.4 to 6.6 significantly attenuated the response by ATP. When extracellular Na+ was replaced by choline chloride and in the presence of the noradrenaline uptake inhibitor desipramine (10 microM), the ATP-evoked [3H]noradrenaline outflow was almost completely abolished, indicating that its underlying mechanism is the sodium-dependent reversal of the noradrenaline transporter. Reverse transcription-polymerase chain reaction analysis revealed that mRNA encoding P2X1, P2X2, P2X3, P2X4, P2X6, P2X7 and P2Y1 receptor subunits were expressed in the brainstem containing catecholaminergic nuclei projecting to the hippocampus, whereas mRNA encoding P2X5, P2Y2, P2Y4, and P2Y6 receptors were absent. Taken together, these results indicate that noradrenergic terminals of the rat hippocampus are equipped with presynaptic facilitatory P2X receptors, displaying a pharmacological profile similar to homomeric P2X1 and P2X3 receptors.
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PMID:P2X receptor activation elicits transporter-mediated noradrenaline release from rat hippocampal slices. 1508 50


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