D'Uva E L, Monti M G, Di Montefiano R
Department of Evolutive and Comparative Biology, University of Naples, Italy.
J Neuroendocrinol. 1997 Sep;9(9):655-62. doi: 10.1046/j.1365-2826.1997.00609.x.
The subcommissural organ (SCO) is a circumventricular organ of glial origin typical of all vertebrates. The SCO releases its secretion into the third ventricle to constitute Reissner's fibre (RF). Reportedly, in reptiles, SCO has cyclic secretory activity related to the reproductive cycle. In this immunocytochemical study we show that, in females of oviparous reptiles (Lacertidae: Podarcis sicula) and in a viviparous species (Scincidae: Chalcides chalcides), SCO secretion consists of hormones, in part of the oxytocin-like (OXY-like) type. The amount of OXY-like material in the cells and in the third ventricle varies according to the different stages of the reproductive cycle. In the oviparous species, OXY-like hormone secretion can be induced by FSH administration at 28 degrees C, in the period of winter reproductive stasis as well. In the viviparous skink, showing an annual single ovulatory cycle, OXY-like secretion is present in the basal region of the cells, and is released into the third ventricle only at delivery. The role of an OXY-like hormone in the SCO is here discussed in relation to the different stages of the reproductive cycle. Its influence on the hypothalamus-hypophysis-gonad axis and its role in the transport of eggs into the ducts in the oviparous species, and at delivery in the viviparous one, are also suggested.
室管膜下器官（SCO）是一种神经胶质起源的脑室周器官，为所有脊椎动物所特有。SCO将其分泌物释放到第三脑室中，形成赖氏纤维（RF）。据报道，在爬行动物中，SCO具有与生殖周期相关的周期性分泌活动。在这项免疫细胞化学研究中，我们发现，在卵生爬行动物（蜥蜴科：意大利壁蜥）和胎生种类（石龙子科：卡尔西德石龙子）的雌性动物中，SCO的分泌物包含激素，部分为催产素样（OXY样）类型。细胞和第三脑室中OXY样物质的含量会根据生殖周期的不同阶段而变化。在卵生种类中，在冬季生殖静止期，28摄氏度下给予促卵泡激素（FSH）可诱导OXY样激素分泌。在胎生石龙子中，其具有一年一度的单一排卵周期，OXY样分泌物存在于细胞的基部区域，仅在分娩时释放到第三脑室中。本文结合生殖周期的不同阶段讨论了SCO中OXY样激素的作用。还提出了其对下丘脑-垂体-性腺轴的影响，以及在卵生种类中将卵输送到输卵管中以及在胎生种类分娩时的作用。
