Developmental sensitivity of the bovine corpus luteum to prostaglandin F2α (PGF2α) and endothelin-1 (ET-1):: Is ET-1 a mediator of the luteolytic actions of PGF2α or a tonic inhibitor of progesterone secretion?
Developmental sensitivity of the bovine corpus luteum to prostaglandin F2α (PGF2α) and endothelin-1 (ET-1):: Is ET-1 a mediator of the luteolytic actions of PGF2α or a tonic inhibitor of progesterone secretion?
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DOI：
10.1095/biolreprod.104.034736
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发表时间：
2005-03-01
影响因子：
3.6
通讯作者：
Flores, JA
中科院分区：
文献类型：
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作者：
Choudhary, E;Sen, A;Flores, JA
我们检测了第4天和第10天牛黄体（CL）的大黄体细胞（LLC）、小黄体细胞（SLC）和内皮细胞对前列腺素（PG）F和内皮素（ET）-1的反应性。使用单细胞方法，我们测试了每种激动剂增加细胞质钙离子浓度（[Ca 2 +]）的能力，作为黄体发育的函数。在从第4天和第10天CL分离的所有细胞群中，所有检测浓度的激动剂均显著（P = 0.05）增加[Ca 2 +]。第10天的类固醇生成细胞比第4天的细胞对PGF（2 α）和ET-1更敏感。激动剂浓度、黄体发育和细胞类型显著影响反应幅度和反应细胞数量。LLC中的响应幅度大于SLC;第10天细胞中的激动剂浓度低于第4天细胞，引起最大幅度的响应。此外，在第10天，作为PGF（2 α）的浓度。增加，更大比例的SLC作出回应。内皮细胞反应最大，无论激动剂浓度和黄体发育。在实验2中，我们测试了发育反应的总分散和类固醇富集细胞的抑制作用的PGF（2 α）和ET-1的基础和LH刺激的孕酮积累。第4天富含PGF（2 α）类固醇的细胞的效力低于第10天;相反，ET-1的效力没有差异。因此，ET-1是孕酮蓄积的紧张性抑制剂，而不是PGF（2 α）作用的介质。PGF（2 α）在早期CL中的较低功效更可能与在这两个发育阶段与其受体相关的信号转导差异有关，而不是与PGF（2 α）不能上调ET-1有关。
We examined the responsiveness of large luteal cells (LLC), small luteal cells (SLC), and endothelial cells of the Day 4 and Day 10 bovine corpus luteum (CL) to prostaglandin (PG) F,, and endothelin (ET)-1. Using a single-cell approach, we tested the ability of each agonist to increase the cytoplasmic concentration of calcium ions ([Ca2+]) as function of luteal development. All tested concentrations of agonists significantly (P = 0.05) increased [Ca2+], in all cell populations isolated from Day 4 and Day 10 CL. Day 10 steroidogenic cells were more responsive than Day 4 cells to PGF(2alpha) and ET-1. Response amplitudes and number of responding cells were affected significantly by agonist concentration, luteal development, and cell type. Response amplitudes were greater in LLC than in SLC; responses of maximal amplitude were elicited with lower agonist concentrations in Day 10 cells than in Day 4 cells. Furthermore, on Day 10, as the concentration of PGF(2alpha). increased, larger percentages of SLC responded. Endothelial cells responded maximally, regardless of agonist concentration and luteal development. In experiment 2, we tested the developmental responsiveness of total dispersed and steroidogenic-enriched cells to the inhibitory actions of PGF(2alpha) and ET-1 on basal and LH-stimulated progesterone accumulation. The potency of PGF(2alpha) steroidogenic-enriched cells on Day 4 was lower than on Day 10; in contrast, the potency of ET-1 was not different. Therefore, ET-1 was a tonic inhibitor of progesterone accumulation rather than a mediator of PGF(2alpha) action. The lower efficacy of PGF(2alpha) in the early CL more likely is related to signal transduction differences associated with its receptor at these two developmental stages than to the inability of PGF(2alpha) to up-regulate ET-1.