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)

In membranes of rat olfactory bulb, a brain region in which muscarinic agonists increase cyclic AMP formation, the muscarinic stimulation of guanosine 5'-O-(3-[35S]thiotriphosphate) ([35S]GTP gamma S) binding was used as a tool to investigate the receptor interaction with the guanine nucleotide-binding regulatory proteins (G proteins). The stimulation of the radioligand binding by carbachol (CCh) was optimal (threefold increase) in the presence of micromolar concentrations of GDP and 100 mM NaCl. Exposure to N-ethylmaleimide and pertussis toxin markedly inhibited the CCh effect, whereas it increased the relative stimulation of [35S]GTP gamma S binding elicited by pituitary adenylate cyclase-activating polypeptide (PACAP). On the other hand, membrane treatment with cholera toxin curtailed the PACAP stimulation of [35S]GTP gamma S binding but did not affect the response to CCh. Like CCh, a number of cholinergic agonists stimulated [35S]GTP gamma S binding in a concentration-dependent and saturable manner. The antagonist profile of the muscarinic stimulation of [35S]GTP gamma S binding was highly correlated with that displayed by the muscarinic stimulation of adenylyl cyclase. These data indicate that the olfactory bulb muscarinic receptors couple to G1/G0, but not to Gs, and support the possibility that activation of G1/G0 mediates the stimulatory effect on adenylyl cyclase activity.
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PMID:Stimulation of guanosine 5'-O-(3-[35S] thiotriphosphate) binding by cholinergic muscarinic receptors in membranes of rat olfactory bulb. 893 89

The metabotropic glutamate receptor (mGluR) cDNAs were originally cloned from rat, except for the mouse cDNA clone encoding mGluR8. Mouse mGluR8 couples weakly to the inhibition of adenylate cyclase, thus hindering the characterization of its pharmacological properties. We isolated a rat mGluR8 cDNA that encodes a protein of 908 amino acids. In situ hybridization revealed prominent mGluR8 mRNA expression in olfactory bulb, pontine gray, lateral reticular nucleus of the thalamus, and piriform cortex. Less abundant expression was detected in cerebral cortex, hippocampus, cerebellum, and mammillary body. Glutamate evoked pertussis toxin-sensitive potassium currents in Xenopus laevis oocytes coexpressing mGluR8 and G protein-coupled inwardly rectifying potassium channels. mGluR8 was also activated by the group III-specific agonist L-2-amino-4-phosphonobutyric acid; (2(S), 1'(S), 2'(S)]- 2-(carboxycyclopropyl)glycine, which has been frequently used as a selective group II agonist; and the nonselective agonist (1(S), 3(R)]-1-aminocyclopentane-1,3-dicarboxylic acid but not by the group I-specific agonist 3,5-dihydroxyphenylglycine or the group II-specific agonist [2(S), 1'(R), 2(R), 3'(R)]-2-(2, 3-dicarboxycyclopropyl)glycine. The agonist profile in order of potency was [2(S), 1'(S), 2'(S)]-2-(carboxycyclopropyl)glycine approximately L-2-amino-4-phosphonobutyric acid > glutamate > > [1(S), 3(R)]-1-aminocyclopentane-1, 3-dicarboxylic acid, with EC50 values of 0.63, 0.67, 2.5, and 47 microM, respectively. Both the group I/II-specific antagonist (R,S)-alpha-methyl-4-carboxyphenylglycine and the group III-specific antagonist alpha-methyl-amino-phosphonobutyrate inhibited mGluR8. The pharmacological profile of mGluR8 is distinct among mGluRs but closely matches that of presynaptic inhibition in some central nervous system pathways. Thus, cellular responses mediated by both group II and III agonists may in some cases reflect activation of mGluR8 rather than multiple mGluR subtypes.
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PMID:Cloning and expression of rat metabotropic glutamate receptor 8 reveals a distinct pharmacological profile. 901 53

In the rat olfactory bulb, activation of opioid receptors enhances basal adenylyl cyclase (EC 4.6.1.1) activity and potentiates enzyme stimulation by Gs-coupled neurotransmitter receptors in a pertussis toxin-sensitive manner. In the present study, we investigated the involvement of G protein betagamma subunits by examining the effects of betagamma scavengers and exogenously added betagamma subunits of transducin (betagamma(t)). The QEHA fragment of type II adenylyl cyclase (50 microM), a peptide that binds to and inactivates betagamma, inhibited the maximal stimulation of adenylyl cyclase activity elicited by Leu-enkephalin (Leu-enk) by about 50%. Similarly, the GDP-bound form of the alpha subunit of transducin (5 nM-1.5 microM), another betagamma scavenger, reduced both the opioid stimulation of basal adenylyl cyclase activity and the potentiation of vasoactive intestinal peptide-stimulated enzyme activity. Under the same experimental conditions, these agents failed to affect the stimulation of the enzyme activity elicited by activation of beta-adrenergic receptors with 1-isoproterenol. Moreover, the addition of betagamma(t)(400 nM) stimulated basal adenylyl cyclase by 80%, and this effect was not additive with that produced by Leu-enk. The data indicate that opioids enhance adenylyl cyclase activity in rat olfactory bulb by promoting the release of betagamma subunits from pertussis toxin-sensitive G proteins Gi/Go.
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PMID:Mediation by G protein betagamma subunits of the opioid stimulation of adenylyl cyclase activity in rat olfactory bulb. 1003 49

In membranes of rat olfactory bulb, muscarinic receptor agonists stimulate basal adenylyl cyclase activity . This response is inhibited by a number of muscarinic receptor antagonists with a rank order of potency suggesting the involvement of the M4 muscarinic receptor subtype. The stimulatory effect does not require Ca2+ and occurs independently of activation of phosphoinositide hydrolysis. Pretreatment with pertussis toxin completely prevents the muscarinic stimulation of adenylyl cyclase, indicating the participation of G proteins of the Gi/Go family. Immunological impairment of the G protein, Gs, also reduces the muscarinic response, whereas concomitant activation of Gs-coupled receptors by CRH or VIP results in a synergistic stimulation of adenylyl cyclase activity. Although these data suggest a role for Gs, a body of evidence indicates that the muscarinic receptors do not interact directly with this G protein. Moreover, the Ca2+/calmodulin (Ca2+/CaM)- and forskolin-stimulated enzyme activities are inhibited by muscarinic receptor activation in a pertussis toxin-sensitive manner and with a pharmacological profile similar to that observed for the stimulatory response. These data indicate that in rat olfactory bulb M4 muscarinic receptors exert a bimodal control on cyclic AMP formation through a sequence of events that may involve activation of Gi/Go proteins, synergistic interaction with Gs and differential modulation of Ca2+/CaM-independent and -dependent forms of adenylyl cyclase.
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PMID:Bimodal regulation of cyclic AMP by muscarinic receptors. Involvement of multiple G proteins and different forms of adenylyl cyclase. 1018 1

Previous studies have shown that GABA(B) receptors facilitate cyclic AMP formation in brain slices likely through an indirect mechanism involving intracellular second messengers. In the present study, we have investigated whether a positive coupling of GABA(B) receptors to adenylyl cyclase could be detected in a cell-free preparation of rat olfactory bulb, a brain region where other Gi/Go-coupled neurotransmitter receptors have been found to stimulate the cyclase activity. The GABA(B) receptor agonist (-)-baclofen significantly increased basal adenylyl cyclase activity in membranes of the granule cell and external plexiform layers, but not in the olfactory nerve-glomerular layer. The adenylyl cyclase stimulation was therefore examined in granule cell layer membranes. The (-)-baclofen stimulation (pD2=4.53) was mimicked by 3-aminopropylphosphinic acid (pD2=4.60) and GABA (pD2=3.56), but not by (+)-baclofen, 3-aminopropylphosphonic acid, muscimol and isoguvacine. The stimulatory effect was counteracted by the GABA(B) receptor antagonists CGP 35348 (pA2=4.31), CGP 55845 A (pA2=7.0) and 2-hydroxysaclofen (pKi=4.22). Phaclofen (1 mM) was inactive. The (-)-baclofen stimulation was not affected by quinacrine, indomethacin, nordihydroguaiaretic acid and staurosporine, but was completely prevented by pertussis toxin and significantly reduced by the alpha subunit of transducin, a betagamma scavenger. The betagamma subunits of transducin stimulated the cyclase activity and this effect was not additive with that produced by (-)-baclofen. In the external plexiform and granule cell layers, but not in the olfactory nerve-glomerular layer, (-)-baclofen enhanced the adenylyl cyclase stimulation elicited by the neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) 38. Conversely, the adenylyl cyclase activity stimulated by either forskolin or Ca2+/calmodulin-(Ca2+/CaM) was inhibited by (-)-baclofen in all the olfactory bulb layers examined. These data demonstrate that in specific layers of rat olfactory bulb activation of GABA(B) receptors enhances basal and neurotransmitter-stimulated adenylyl cyclase activities by a mechanism involving betagamma subunits of Gi/Go. This positive coupling is associated with a widespread inhibitory effect on forskolin- and Ca2+/CaM-stimulated cyclic AMP formation.
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PMID:GABA(B) receptor-mediated stimulation of adenylyl cyclase activity in membranes of rat olfactory bulb. 1018 76

Pretreatment of olfactory ensheathing cells (OECs) with Pertussis toxin increased the number of subsequently cocultured adult retinal ganglion cells (RGCs) regrowing neurites without affecting neuronal survival. Pertussis toxin (PTx) inactivated an OEC G(i/o) protein as pretreating OECs with the PTx B-oligomer subunit had no effect on RGC neurite regrowth. However, the B-oligomer was responsible for decreasing the marked orientation of neurite regrowth on the OEC substrate. Simultaneous incubation of OECs with PTx and a depolarizing concentration of KCl abolished the increase in neurite regrowth from cocultured RGCs, but exposure to a depolarizing KCl concentration after OECs had been PTx-treated had no effect. Our evidence supports the hypothesis that G-protein-regulated calcium signaling plays a significant role in OEC support for CNS axonal regeneration.
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PMID:Manipulation of olfactory ensheathing cell signaling mechanisms: effects on their support for neurite regrowth from adult CNS neurons in coculture. 1460 64

1 Naloxone benzoylhydrazone (NalBzoH) has initially been developed as an agonist of the pharmacologically defined kappa3-opioid receptor and has recently been employed as an antagonist at the opioid receptor-like (ORL1) receptor. In the present study, we investigated the ability of NalBzoH to elicit agonist-like effects on receptor signalling in distinct layers of rat olfactory bulb, a brain region where we have demonstrated the presence of opioid and ORL1 receptors coupled to both stimulation and inhibition of cyclic AMP formation. 2 In membranes of the olfactory nerve-glomerular layer (ON-GL), external plexiform layer (EPL) and granule cell layer (GRL), NalBzoH elicited a concentration-dependent stimulation of guanosine-5'-O-(3-[35S]-thio)triphosphate ([35S]GTPgammaS) binding with pEC50 values ranging from 7.36 to 7.86, whereas the kappa1-opioid receptor agonists (-)-U-50,488 and U-69,593 were inactive. 3 In membranes of GRL, but not ON-GL and EPL, NalBzoH stimulated basal adenylyl cyclase activity by 40% with a pEC50 of 8.14, and significantly potentiated the net enzyme stimulation elicited by corticotropin-releasing hormone and pituitary adenylate cyclase-activating peptide 38. Pertussis toxin prevented the NalBzoH stimulations of [35S]GTPgammaS binding and adenylyl cyclase activity. 4 In membranes of EPL and GRL, but not ON-GL, NalBzoH elicited a concentration-dependent inhibition of forskolin-stimulated adenylyl cyclase activity with pEC50 values of 8.07 and 8.08, respectively. 5 At concentrations that completely blocked the actions of nociceptin/orphanin FQ (N/OFQ), the ORL1 receptor antagonists CompB and [Nphe1]N/OFQ(1-13)NH2 failed to antagonize either the stimulatory or the inhibitory effect of NalBzoH on cyclic AMP formation. Similarly, the kappa1-opioid receptor antagonist nor-binaltorphimine counteracted the NalBzoH effects with relatively low potencies (pKi values=7.67-8.09). 6 Conversely, the selective delta-opioid receptor antagonist TIPP (pKi=9.10) and the selective mu-opioid receptor antagonist CTAP (pKi=8.27) reduced the inhibitory effect of NalBzoH by 70 and 30%, respectively. Moreover, TIPP and CTAP potently inhibited the NalBzoH stimulation of cyclic AMP, each antagonist maximally causing 50% blockade of the agonist response. 7These data demonstrate that in the olfactory bulb NalBzoH activates receptor signalling by acting through delta- and mu-opioid receptors and independently of ORL1 and kappa1-opioid receptors.
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PMID:G protein activation and cyclic AMP modulation by naloxone benzoylhydrazone in distinct layers of rat olfactory bulb. 1545 72

We demonstrate that there are significantly more p75 neurotrophin receptor- (NTR)-expressing cells in olfactory ensheathing cell (OEC) primary cultures from olfactory nerve rootlets (ONR), but a greater proportion of O4 antigen- and PSA-NCAM-expressing cells in parallel cultures from the nerve fibre layer of the olfactory bulb (OB). By co-culturing adult rat retinal ganglion cells (RGCs) with OECs derived from either ONR or OB tissue, we compared their neurite regrowth-promoting properties. In phenotypically unsorted cultures, there is greater RGC neurite regrowth on ONR OECs compared to OB OECs. Following immunoselection of ONR cells for p75 NTR, there is increased RGC neurite regrowth on the enriched population compared to the unselected cell population or the p75 NTR depleted population. When p75 NTR-enriched cells from ONR and OB cultures are compared directly, tissue source-related differences are no longer observed. Our previous work implicated a pertussis toxin (PTx)-sensitive G protein-linked signalling pathway in OEC regulation of neurite regrowth. We show that this pathway probably operates in interactions between the p75 NTR-positive and -negative cells; separated populations lose the PTx-mediated enhancement of neurite regrowth-promoting properties seen in mixed cultures. Optimum neurite regrowth is observed when both phenotypes are present in cultures from either ONR or OB, and where glial G-protein signalling is disabled by PTx before co-culture with neurons. We thus propose that p75 NTR-positive cells, whilst being the more effective neurite regrowth promoting subpopulation in isolation, cooperate with negative cells to provide optimum support for axonal regrowth.
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PMID:Functional differences and interactions between phenotypic subpopulations of olfactory ensheathing cells in promoting CNS axonal regeneration. 1559 40

Proteinase-activated receptors (PARs) are a family of four G protein-coupled receptors that are widely distributed in the CNS and involved in neural cell proliferation, differentiation and survival. The olfactory system undergoes continuous neurogenesis throughout life and may represent a critical target of PAR cellular actions. In the present study we investigated the functional activity of PAR1 and PAR2 in microdissected tissue preparations of olfactory nerve-glomerular layer (ON-GL), external plexiform layer (EPL) and granule cell layer (GRL) of the rat main olfactory bulb and in primary cultures of olfactory neuroepithelial cells. Activation of either PAR1 or PAR2 regulated multiple signaling pathways, including activation of pertussis-toxin sensitive Gi/o proteins, inhibition of cyclic AMP formation, stimulation of Gq/11-mediated phosphoinositide (PI) hydrolysis, phosphorylation of Ca2+/calmodulin-dependent protein kinase II and activation of the monomeric G protein Rho, predominantly in ON-GL, whereas only activation of Rho was detected in the deeper layers. Olfactory nerve lesion by nasal irrigation with ZnSO4 induced a marked decrease of PAR signaling in ON-GL. In primary cultures of olfactory neurons, double immunofluorescence analysis showed the localization of PAR1 and PAR2 in cells positive for olfactory-marker protein and neuron-specific enolase. Cell exposure to either nanomolar concentrations of thrombin and trypsin or PAR-activating peptides caused rapid neurite retraction. This study provides the first characterization of the laminar distribution of PAR1 and PAR2 signaling in rat olfactory bulb, demonstrates the presence of the receptors in olfactory sensory neurons and suggests a role of PARs in olfactory sensory neuron neuritogenesis.
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PMID:Proteinase-activated receptors 1 and 2 in rat olfactory system: layer-specific regulation of multiple signaling pathways in the main olfactory bulb and induction of neurite retraction in olfactory sensory neurons. 1743 82

Progestin stimulation of sperm hypermotility remains poorly understood despite having been described in numerous vertebrate species. We show here that progestin stimulation of sperm hypermotility in a teleost, the Atlantic croaker (Micropogonias undulatus) is associated with activation of an olfactory G protein (Golf). Furthermore, we provide evidence that this progestin action is mediated by membrane progestin receptor-alpha (mPRalpha). Golf was identified in croaker sperm membranes and was specifically activated after treatment with the progestin 17,20beta,21-trihydroxy-4-pregnen-3-one (20beta-S). Treatment of sperm membranes with 20beta-S caused an increase in cAMP production, which was blocked by pretreatment with cholera toxin and two membrane adenylyl cyclase inhibitors: 2',5'-dideoxyadenosine and SQ22536. Moreover, preincubation of croaker sperm with 2',5'-dideoxyadenosine and SQ22536 resulted in a significant inhibition of 20beta-S-stimulated hypermotility. Binding of [3H]20beta-S to sperm membranes was decreased after pretreatment with GTPgammaS but not pertussis toxin, suggesting the receptor is coupled to a pertussis toxin-insensitive G protein. Golf and mPRalpha were coexpressed on the sperm midpiece and flagella and were coimmunoprecipitated from sperm membranes. Finally, expression of mPRalpha protein on sperm increased after in vivo treatment with LHRH and was associated with increased induction of sperm motility by 20beta-S. These results suggest that 20beta-S activates mPRalpha in croaker sperm, which in turn activates Golf and membrane adenylyl cyclase to stimulate sperm hypermotility. Taken together these findings provide a plausible mechanism by which progestins stimulate sperm hypermotility in croaker and provide the first evidence of hormonal activation of Golf in any species.
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PMID:Progestin signaling through an olfactory G protein and membrane progestin receptor-alpha in Atlantic croaker sperm: potential role in induction of sperm hypermotility. 1880 4


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