Ligand-induced rapid desensitization causes structural alteration of rat ovarian LH/hCG receptor
| Autor: | Jezová M, M Tatara, Kolena J, S. Scsukova, Vranová J |
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| Rok vydání: | 2009 |
| Předmět: |
endocrine system
medicine.medical_specialty Hot Temperature medicine.drug_class Endocrinology Diabetes and Metabolism medicine.medical_treatment Membrane lipids Fluorescence Polarization Luteal phase Biology Chorionic Gonadotropin Endocrinology Drug Stability In vivo Cell surface receptor Internal medicine Internal Medicine medicine Animals Pseudopregnancy Rats Wistar reproductive and urinary physiology Fluorescent Dyes Desensitization (medicine) urogenital system Cell Membrane Ovary Drug Tolerance General Medicine Receptors LH Rats Spectrometry Fluorescence Membrane Female Gonadotropin Diphenylhexatriene hormones hormone substitutes and hormone antagonists Fluorescence anisotropy Adenylyl Cyclases |
| Zdroj: | Experimental and Clinical Endocrinology & Diabetes. 104:459-463 |
| ISSN: | 1439-3646 0947-7349 |
| DOI: | 10.1055/s-0029-1211485 |
| Popis: | The role of the physical state of ovarian membranes was studied in the process of the early desensitization of the LH/hCG receptor. Thirty min after injection of a desensitizing dose of hCG to rats, the hCG-responsive adenylylcyclase activity was reduced, whereas hCG binding to ovarian membranes was still normal. Early desensitization decreased rigidity of membrane lipids, determined by fluorescence polarization of DPH. Possible structure-functional properties of the LH/hCG receptor were analyzed by thermal perturbation technique. Desensitization decreased thermal stability of the LH/ hCG receptor in membranes and in proteoliposomes. Desensitization modified the quenching of protein fluorescence and intrinsic fluorescence spectral properties of membranes. The Stern-Volmer constants for control and desensitized membranes were found to be 4.3 and 5.5, respectively, indicating that desensitization elevated the accessibility of fluorophores for acrylamide. The changes of the physical properties of membranes resulting from desensitization was exhibited solely in the treatment with hCG in vivo, but not in vitro. The results suggest that the hCG-induced alteration of the physical state of luteal membranes may be a requirement for the induction of changes that lead to desensitization. |
| Databáze: | OpenAIRE |
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