TY - JOUR
T1 - Rat oocyte maturation
T2 - Role of calcium in hormone action
AU - Goren, S.
AU - Oron, Y.
AU - Dekel, N.
N1 - Funding Information:
This study was supported by grants from The Israel Academy of Sciences and Humanities to N.D. and Y.O. and U.S.A.-Israel Binational Science Foundation to N.D. We thank R. Levin for secretarial assistance.
PY - 1990/8/20
Y1 - 1990/8/20
N2 - 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.
AB - 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.
KW - (Rat)
KW - Gonadotropin-releasing hormone
KW - Luteinizing hormone
KW - Oocyte maturation
KW - Oocyte-cumulus interaction
UR - http://www.scopus.com/inward/record.url?scp=0025108946&partnerID=8YFLogxK
U2 - 10.1016/0303-7207(90)90103-F
DO - 10.1016/0303-7207(90)90103-F
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AN - SCOPUS:0025108946
SN - 0303-7207
VL - 72
SP - 131
EP - 138
JO - Molecular and Cellular Endocrinology
JF - Molecular and Cellular Endocrinology
IS - 2
ER -