Rat oocyte maturation: role of calcium in hormone action
| Autor: | Nava Dekel, Y. Oron, Sari Goren |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
endocrine system
medicine.medical_specialty medicine.drug_class chemistry.chemical_element Gonadotropin-releasing hormone Biology Calcium Biochemistry Endocrinology Internal medicine medicine Extracellular Animals Molecular Biology Egtazic Acid Calcimycin Voltage-dependent calcium channel Ionomycin Rats Inbred Strains Luteinizing Hormone Oocyte Rats medicine.anatomical_structure chemistry Bucladesine Oocytes Hormone analog Female Calcium Channels Gonadotropin Luteinizing hormone |
| Zdroj: | Molecular and cellular endocrinology. 72(2) |
| ISSN: | 0303-7207 |
| Popis: | We studied the role of extracellular calcium (Ca0) in oocyte maturation and oocyte-cumulus cells interaction in rat follicles in vitro. Luteinizing hormone (LH) or a gonadotropin-releasing hormone analog (GnRHa) induced full maturation at [Ca0] = 1.3 mM. At [Ca0] = 0.6 mM, maturation induced by LH or GnRHa was inhibited by 65%. Chelatin of [Ca0] resulted in 45% maturation and neither hormone caused a further increase of maturation. [Ca0] = 20 mM enhanced the response to suboptimal concentrations of GnRHa but inhibited that to LH. Divalent cation ionophores caused [Ca0]-dependent maturation, which was fully inhibited by dibutyryl cAMP. Changes in [Ca0] also affected oocyte-cumulus interaction. At [Ca0] = 1.3 mM, either LH or GnRHa caused partial dispersion of the cumulus. Chelation of [Ca0] also resulted in an almost complete dispersion of the cumulus. The ionophores, however, caused maturation with the oocyte-cumulus complex preserved intact. Our data suggest that GnRHa may induce maturation via cAMP-sensitive calcium mobilization into the oocyte-cumulus-granulosa complex. |
| Databáze: | OpenAIRE |
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