Human Photosynthesis® Research Center, Aguascalientes 20000, Mexico.
King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
CNS Neurol Disord Drug Targets. 2018;17(10):743-756. doi: 10.2174/1871527317666180904093430.
BACKGROUND & OBJECTIVE: Regulation of composition, volume and turnover of fluids surrounding the brain and damp cells is vital. These fluids transport all substances required for cells and remove the unwanted materials. This regulation tends to act as barrier to prevent free exchange of materials between the brain and blood. There are specific mechanisms concerned with fluid secretion of the controlled composition of the brain, and others responsible for reabsorption eventually to blood and the extracellular fluid whatever their composition is. The current view assumes that choroidal plexuses secrete the major part of Cerebrospinal Fluid (CSF), while the Blood-Brain Barrier (BBB) has a much less contribution to fluid production, generating Interstitial Fluid (ISF) that drains to CSF. The skull is a rigid box; thereby the sum of volumes occupied by the parenchyma with its ISF, related connective tissue, the vasculature, the meninges and the CSF must be relatively constant according to the Monroe-Kellie dogma. This constitutes a formidable challenge that normal organisms surpass daily. The ISF and CSF provide water and solutes influx and efflux from cells to these targeted fluids in a quite precise way. Microvessels within the parenchyma are sufficiently close to every cell where diffusion areas for solutes are tiny. Despite this, CSF and ISF exhibit very similar compositions, but differ significantly from blood plasma. Many hydrophilic substances are effectively prevented from the entry into the brain via blood, while others like neurotransmitters are extremely hindered from getting out of the brain. Anatomical principle of the barrier and routes of fluid transfer cannot explain the extraordinary accuracy of fluids and substances needed to enter or leave the brain firmly. There is one aspect that has not been deeply analyzed, despite being prevalent in all the above processes, it is considered a part of the CSF and ISF dynamics. This aspect is the energy necessary to propel them properly in time, form, space, quantity and temporality.
The recent hypothesis based on glucose and ATP as sources of energy presents numerous contradictions and controversies. The discovery of the unsuspected intrinsic ability of melanin to dissociate and reform water molecules, similar to the role of chlorophyll in plants, was confirmed in the study of ISF and CSF biology.
调节脑周围液体的组成、体积和周转率至关重要。这些液体为细胞运输所有必需的物质,并清除不需要的物质。这种调节作用类似于阻止大脑和血液之间自由交换物质的屏障。有特定的机制涉及到脑液的分泌,其组成受到控制,而其他机制则负责再吸收最终进入血液和细胞外液,无论其组成如何。目前的观点认为脉络丛是脑脊液(CSF)的主要分泌部位,而血脑屏障(BBB)对液体生成的贡献要小得多,它产生的间质液(ISF)最终排入 CSF。颅骨是一个刚性的盒子;因此,根据门罗-凯利教条,由实质及其 ISF、相关结缔组织、脉管系统、脑膜和 CSF 组成的容积必须相对恒定。这是正常生物体每天都要面对的巨大挑战。ISF 和 CSF 以一种非常精确的方式为细胞提供水和溶质的流入和流出。实质内的微血管与每个细胞都非常接近,溶质的扩散区域很小。尽管如此,CSF 和 ISF 的组成非常相似,但与血浆有很大的不同。许多亲水性物质有效地被阻止从血液进入大脑,而其他物质如神经递质则非常难以离开大脑。尽管屏障的解剖学原理和液体转移途径不能解释进入或离开大脑的液体和物质的精确性,但仍有一个方面尚未得到深入分析,尽管它在所有上述过程中都很普遍,它被认为是 CSF 和 ISF 动力学的一部分。这个方面是推动它们在时间、形式、空间、数量和时间性方面正确流动所需的能量。
基于葡萄糖和 ATP 作为能量来源的最新假设存在诸多矛盾和争议。在对 ISF 和 CSF 生物学的研究中,证实了黑色素将水分子离解和重组的内在能力,类似于植物中叶绿素的作用,这一令人惊讶的发现。