Role of luteal cell nucleus in the expression of gonadotropin action.
Role of luteal cell nucleus in the expression of gonadotropin action.
复制标题
黄体细胞核在促性腺激素作用表达中的作用。
DOI：
10.1007/bf03349088
复制
发表时间：
1991
影响因子：
5.4
通讯作者：
Lei,ZM
中科院分区：
文献类型：
--
作者：
BibbinsJr,PE;Rao,CV;Carman,FR;Chegini,N;Lei,ZM
Gonadotropin receptors are not only present in cell membranes, but also in nuclei of bovine and human luteal cells. hCG/hLH can directly regulate several nuclear functions. To further investigate the role of luteal cell nucleus in the expression of gonadotropin action, the effect of enucleation of luteal cells on gonadotropin receptors and gonadotropin response was studied. Luteal cytoplasts were prepared by colchicine treatment of purified whole luteal cells followed by centrifugation at 37 C in a Percoll gradient. The cytoplasts were 85 to 90% pure with a recovery of about 57%. Cytoplasts were viable as determined by trypan blue exclusion (87%) and metabolically competent as determined by3H-leucine incorporation into proteins. On the day of preparation, the viability and metabolic competency of cytoplasts were similar to control cells, i.e. untreated and colchicine treated whole luteal cells. In addition, cytoplasts and control cells showed a similar decline in number and viability during storage at 4 C. While control cells continue to be metabolically competent, cytoplasts showed a dramatic decline by 48 h of storage at 4 C. Neither the cytoplasts nor control cells degraded1251-hCG. The kinetics of1251-hCG association and dissociation, specificity and affinity of binding to cytoplasts were similar to control cells. However, the number of available gonadotropin receptors in cytoplasts was significantly lower than in control cells. Cytoplasts contained lower progesterone levels and more importantly, they could not be stimulated by 10 nM hCG or 10 mM dibutyry1 cyclic AMP to produce more progesterone. Controls cells, on the other hand, contained higher progesterone levels and responded to hCG and dibutyryl cyclic AMP stimulation. In summary, removal of nuclei from luteal cells results in a partial loss of gonadotropin receptors and complete loss of steroidogenic response to hCG and dibutyryl cyclic AMP. Whether the loss of steroidogenic response was related or coincidental to partial gonadotropin receptors loss is unknown.
