Beijing Sport University, Beijing China.
Physiol Res. 2012;61(3):277-86. doi: 10.33549/physiolres.932257. Epub 2012 Apr 5.
The hypothalamic supraoptic and paraventricular nuclei consist of oxytocin and arginine vasopressin synthesizing neurons that send projections to the neurohypophysis. A growing body of evidence in adult animals and young animals at near term confirmed the structure and function in the vasopressinergic and oxytocinergic network. However, whether those distinctive neural networks are formed before near term is largely unknown. This study determined the special patterns in location and distribution of oxytocin- and vasopressin-neurons in the paraventricular and supraoptic nuclei from preterm to term in the ovine fetuses. The results showed that oxytocin- and vasopressin-neurons were present in both nuclei at the three gestational time periods (preterm, near term, and term). In the paraventricular nuclei, vasopressin-cells concentrated mainly in the core of the middle magnocellular paraventricular nuclei, and oxytocin-cells were scattered surrounding the core. In the supraoptic nuclei, vasopressin-cells mostly located in the ventral part, and oxytocin-cells in the dorsal part. The data demonstrated that the special distributed patterns of vasopressin- and oxytocin-neuron network have formed in those two nuclei at least from preterm. Intracerebroventricular injection of angiotensin II significantly increased fetal plasma oxytocin and vasopressin levels at preterm, which was associated with an increase of oxytocin- and vasopressin-neuron activity marked with c-fos expression. The data provided new evidence for the structural and functional development of the oxytocin- and vasopressin-network before birth.
下丘脑视上核和室旁核包含合成催产素和精氨酸血管加压素的神经元，这些神经元向神经垂体投射。越来越多的证据表明，在成年动物和接近足月的幼小动物中，血管加压素能和催产素能网络具有结构和功能。然而，在接近足月之前，这些独特的神经网络是否形成，在很大程度上还不清楚。本研究在绵羊胎儿从早产到足月的过程中，确定了室旁核和视上核中催产素和血管加压素神经元的位置和分布的特殊模式。结果表明，在三个妊娠期（早产、接近足月和足月），两个核中均存在催产素和血管加压素神经元。在室旁核中，血管加压素细胞主要集中在中间大细胞室旁核的核心，而催产素细胞则散在核心周围。在视上核中，血管加压素细胞主要位于腹侧部分，而催产素细胞位于背侧部分。这些数据表明，至少从早产开始，血管加压素和催产素神经元网络的特殊分布模式已经在这两个核中形成。向侧脑室注射血管紧张素Ⅱ可显著增加早产胎儿的血浆催产素和血管加压素水平，这与催产素和血管加压素神经元活性的增加有关，表现为 c-fos 表达增加。这些数据为出生前催产素和血管加压素网络的结构和功能发育提供了新的证据。
