Parkinson's disease (PD) is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. Dopamine precursor L-dopa is used as the first-line treatment for PD. Evidence suggests neuroprotective effects of estrogens in PD. Since both estradiol (E2) and L-dopa act as regulators of prolactin (PRL) secretion from the pituitary gland, we investigated their effect on the expression of PRL in prolactinomas that developed in ovariectomized hemiparkinsonian rats treated with 17b-E2. We also investigated the effect of E2 and L-dopa on the expression of synaptotagmin IV (Syt IV), an immediate early gene whose product is abundant in the pituitary gland and was found to be highly co-expressed with PRL in lactotrophs (>90%). The hemiparkinsonian rat model was obtained by unilateral lesioning of dopaminergic nigrostriatal neurons. Rats received silastic tubing implants with E2 and were treated with L-dopa. Enzyme-linked immunosorbent assay and immunohistochemistry were used to assess the serum concentrations of PRL and E2 and expression of PRL and Syt IV in the tissue of adenohypophysis, respectively. We found that high levels of serum 17b-E2 were associated with the upregulation of Syt IV and PRL in PRL-ir cells, while treatment with L-dopa decreased the size of prolactinomas and downregulated Syt IV but had no effect on PRL expression or serum concentrations.

中文翻译：

---

左旋多巴对去势半帕金森大鼠 17-β-雌二醇诱导的催乳素瘤中催乳素和突触结合蛋白 IV 表达的影响。

帕金森病（PD）是一种主要影响运动系统的中枢神经系统长期退行性疾病。多巴胺前体左旋多巴被用作 PD 的一线治疗。有证据表明雌激素对 PD 有神经保护作用。由于雌二醇 (E2) 和左旋多巴都作为垂体分泌催乳素 (PRL) 的调节剂，我们研究了它们对用 17b-E2 治疗的去卵巢半帕金森病大鼠中发生的催乳素瘤中 PRL 表达的影响。我们还研究了 E2 和左旋多巴对突触结合蛋白 IV (Syt IV) 表达的影响，突触结合蛋白 IV (Syt IV) 是一种直接早期基因，其产物在垂体中丰富，被发现与泌乳素中的 PRL 高度共表达 (>90 %）。通过单侧损伤多巴胺能黑质纹状体神经元获得偏帕金森大鼠模型。大鼠接受具有 E2 的硅橡胶管植入物并用左旋多巴治疗。酶联免疫吸附试验和免疫组织化学分别用于评估腺垂体组织中PRL和E2的血清浓度以及PRL和Syt IV的表达。我们发现高水平的血清 17b-E2 与 PRL-ir 细胞中 Syt IV 和 PRL 的上调有关，而左旋多巴治疗减少了催乳素瘤的大小并下调了 Syt IV，但对 PRL 表达或血清没有影响浓度。酶联免疫吸附试验和免疫组织化学分别用于评估腺垂体组织中PRL和E2的血清浓度以及PRL和Syt IV的表达。我们发现高水平的血清 17b-E2 与 PRL-ir 细胞中 Syt IV 和 PRL 的上调有关，而左旋多巴治疗减少了催乳素瘤的大小并下调了 Syt IV，但对 PRL 表达或血清没有影响浓度。酶联免疫吸附试验和免疫组织化学分别用于评估腺垂体组织中PRL和E2的血清浓度以及PRL和Syt IV的表达。我们发现高水平的血清 17b-E2 与 PRL-ir 细胞中 Syt IV 和 PRL 的上调有关，而左旋多巴治疗减少了催乳素瘤的大小并下调了 Syt IV，但对 PRL 表达或血清没有影响浓度。