Neuropeptide Y enhances LHRH binding to rat gonadotrophs in primary culture
| Autor: | Claude Kordon, R. Rasolonjanahary, A. L'heritier, P. Leblanc |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
medicine.medical_specialty Calmodulin Gi alpha subunit Pertussis toxin Piperazines Gonadotropin-Releasing Hormone Cellular and Molecular Neuroscience chemistry.chemical_compound Endocrinology GTP-Binding Proteins Pituitary Gland Anterior Internal medicine 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine mental disorders medicine Cyclic AMP Animals Neuropeptide Y Virulence Factors Bordetella Rats Wistar Protein kinase C Cells Cultured Protein Kinase C Sulfonamides Forskolin biology Endocrine and Autonomic Systems Colforsin General Medicine Neuropeptide Y receptor Isoquinolines humanities Rats Calmodulin dependent protein kinase Neurology chemistry Pertussis Toxin Peptide YY biology.protein Tetradecanoylphorbol Acetate |
| Zdroj: | Neuropeptides. 26(2) |
| ISSN: | 0143-4179 |
| Popis: | Incubation of dispersed adenohypophyseal cells from intact male rats with Neuropeptide Y (NPY) or Peptide YY (YY) at 21 degrees C increased maximal 125I LHRHa binding (Bmax) by about 50%. In presence of 10(-7) M NPY, Bmax calculated from saturation isotherm curves was 15.3 +/- 1.9 fmoles x mg-1 proteins, as compared to 10 +/- 1 fmoles x mg-1 in control incubates. The increase was dose dependent with an EC50 of 6.3 +/- 1.8 10(-10) M NPY. Preincubation of the cells with pertussis toxin (PT, 15 ng/ml) for 24 h abolished the effect, suggesting coupling of NPY receptors to G alpha o or G alpha i proteins. NPY 10(-7) M inhibited basal and Forskolin 10(-5) M stimulated intracellular cyclic AMP formation by 31.9 +/- 3.4% and 30.6 +/- 2.3% respectively. Desensitization of protein kinase C by overnight preincubation of the cells with 10(-6) M phorbol ester (PMA) did not interfere with the effect of NPY. In contrast, W7, a calmodulin inhibitor, as well as H7, a protein kinase C inhibitor with a relatively wide spectrum, suppressed the effect of NPY with IC50 of 1.4 +/- 0.6 10(-6) M and 2.2 +/- 0.5 10(-5) M, respectively. Taken together, these results suggest that NPY is able to control unmasking of a cryptic LHRH receptor pool in pituitary cells by a process dependent upon both GTP binding proteins and calmodulin dependent protein kinase. |
| Databáze: | OpenAIRE |
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