• Natural Product Sciences
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• v.11 no.3
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• pp.131-135
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• 2005

Methanolic extracts of ninety-five medicinal plants were screened for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Alpinia officinarum, Belamcanda chinensis, Leonurus heterophyllus, Pinus densiflora, Polygonatum sibiricum and Sambucus williamsii showed significant inhibitory effects on the platelet-activating factor (PAF) receptor binding.

• Natural Product Sciences
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• v.2 no.2
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• pp.86-89
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• 1996

Methanolic extracts of 25 species of Malaysian medicinal plants were screened for platelet-activating factor (PAF) receptor binding activity using rabbit platelet. Extracts of Cinnamomum sintoc, Ixonanthes iconsandra, Paederia foetida, Piper aduncum, Premna integrifolia, Ardisia crispa, and Ardisia elliptica showed significant inhibitory effect on the platelet-activating factor (PAF) receptor binding.

• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.178-181
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• 2005

Methanolic extracts of fifteen Chinese medicinal plants were screened for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Campsis grandiflora, Dalbergia odorifera, Vaccaria segetalis and Zanthoxylum nitidum showed significant inhibitory effects on the platelet-activating factor (PAF) receptor binding. Campsis grandiflora, Dalbergia odorifera, Vaccaria segetalis and Zanthoxylum nitidum inhibited 52%, 56%, 70%, and 66% respectively at the concentration of 0.2 mg/ml.

• Development and Reproduction
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• v.25 no.4
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• pp.225-234
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• 2021

The present study aimed to investigate the mechanism of cell surface receptor loss by two constitutively activating mutants (designated L469R, and D590Y) and two inactivating mutants (D417N and Y558F) of the luteinizing hormone receptor (LHR) in the Japanese eel Anguilla japonica, known to naturally occur in human LHR transmembrane domains. We investigated cell surface receptor loss using an enzyme-linked immunosorbent assay in HEK 293 cells. The expression level of wild-type eel LHR was considered to be 100%, and the expression levels of L469R and D417N were 97% and 101%, respectively, whereas the expression levels of D590Y and Y558F slightly increased to approximately 110% and 106%, respectively. The constitutively activating mutants L469R and D590Y exhibited a decrease in cell surface loss in a manner similar to that of wild-type eel LHR. The rates of loss of cell surface agonist-receptor complexes were observed to be very rapid (2.6-6.2 min) in both the wild-type eel LHR and activating mutants. However, cell surface receptor loss in the cells expressing inactivating mutants D417N and Y558F was slightly observed in the cells expressing inactivating mutants D417N and Y558F, despite treatment with a high concentration of agonist. These results provide important information on LHR function in fish and the regulation of mutations of highly conserved amino acids in glycoprotein hormone receptors.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.41-47
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• 2000

Gonadotropin receptors are members of the seven-transmembrane (TM) receptor family, Point mutations in the lutropin/choriogonadotropin receptor (LH/CGR) have been shown to cause constitutive activation which results in precocious puberty in affected males, We introduced one of the mutation, D556Y, into the LH/CG receptor and the same high affinity binding mutant (D556Y) receptor clone cell for wild type LH/CGR (LH/CGR-wt) was chosen for further analysis, In contrast to cells expressing LH/CGR-wt, it was demonstrated that the mutant receptor exhibited markedly increased basal cAMP production in the absence of agonist, suggesting that autonomous Leydig cell activity in familial male-precocious puberty (FMPP) is caused by a constitutively activating LH/CGR.

• IMMUNE NETWORK
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• v.9 no.2
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• pp.41-45
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• 2009

Activating and inhibitory cell surface receptors play important roles in regulation of immune responses. Recent progress has demonstrated that many inhibitory receptors pair with activating, as well as inhibitory, isoforms, both of whose genes are located in small clusters on a chromosome. We and others identified paired activating and inhibitory immunoglobulin-like receptors, designated myeloid-associated immunoglobulin-like receptors (MAIR) (CD300). MAIR is a multigene family consisting of nine genes on a small segment of mouse chromosome 11. MAIR family receptors are preferentially expressed on myeloid cells, including macrophages, dendritic cells, granulocytes, and bone-marrow-derived cultured mast cells, and a subset of B cells and regulate activation of these cells. Thus, MAIR plays an important role in innate immunity mediated by myeloid cells.

• Natural Product Sciences
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• v.7 no.2
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• pp.33-37
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• 2001

Methanol extracts of eighty Chinese medicinal plants were investigated for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Extracts of Cratoxylon ligustrinum, Kalimeris indica, Euonymus japonica, Ophiopogon japonicus, Gleditsia sinensis, Clausena lansium, Agave sisalana were found to exhibit significant inhibitory effects. Chloroform partition of the Methanol extract of Kalimeris indica was further fractionated by column chromatography to afford one strong active subfraction with 93.6% inhibition at a concentration of $100{\mu}g/ml$.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.29-34
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• 2022

Pheromone biosynthesis in the pheromone gland is triggered from release of pheromone biosynthesis-activating neuropeptide (PBAN) synthesized in the suboesophageal ganglion. PBAN binds to its receptor on the epithelial cell membrane and activates signal transduction pathways for the pheromone biosynthesis. This study reviews sex pheromone, PBAN and its receptor, and pheromone biosynthesis pathway of Maruca vitrata.

• Development and Reproduction
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• v.25 no.3
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• pp.133-143
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• 2021

In contrast to the human lutropin receptor (hLHR) and rat LHR (rLHR), very few naturally occurring mutants in other mammalian species have been identified. The present study aimed to delineate the mechanism of signal transduction by three constitutively activating mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of the eel LHR, known to be naturally occurring in human LHR transmembrane domains. The mutants were constructed and measured cyclic adenosine monophosphate (cAMP) accumulation via homogeneous time-resolved fluorescence assays in Chinese hamster ovary (CHO)-K1 cells. The activating mutant cells expressing eel LHR-M410T, L469R, and D590Y exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist treatment, respectively. However, inactivating mutant cells expressing D417N and Y558F did not completely impaired signal transduction. Specifically, signal transduction in the cells expressing activating mutant L469R was not occurred with a further ligand stimulation, showing that the maximal response exhibited approximately 53% of those of wild type receptor. Our results suggested that the constitutively activating mutants of the eel LHR consistently occurred without agonist treatment. These results provide important information of LHR function in fish and regulation with regard to mutations of highly conserved amino acids in glycoprotein hormone receptors.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.41-48
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• 1998

The present study was undertaken to characterize homocysteic acid (HCA)-and cysteic acid (CA)-mediated formation of inositol phosphates (InsP) in primary culture of rat cerebellar granule cells. HCA and CA stimulated InsP formation in a dose-dependent manner, which was prevented by the N-methyl-D-aspartate (NMDA) receptor antagonist D,L-2-amino-5-phosphopentanoic acid (APV). CA-, but not HCA-, mediated InsP formation was in part prevented by the metabotropic glutamate receptor antagonist ?${\alpha}$-methyl-4-carboxyphenylglycine ($({\pm})$-MCPG). Both HCA- and CA-mediated increases in intracellular calcium concentration were completely blocked by APV, but were not altered by $({\pm})$-MCPG. CA-mediated InsP formation was in part prevented by removal of endogenous glutamate. In contrast, the glutamate transport blocker L-aspartic acid-${\beta}$-hydroxamate synergistically increased CA responses. These data indicate that in cerebellar granule cells HCA mediates InsP formation wholly by activating NMDA receptor. In contrast, CA stimulates InsP formation by activating both NMDA receptor and metabotropic glutamate receptor, and in part by releasing endogenous glutamate into extracellular milieu.