Estimating the density of fluorescent nanoparticles in the primo vessels in the fourth ventricle and the spinal cord of a rat

Abstract

Abstract. The primo vascular system is a novel circulatory system forming a network throughout an animal's body. Primo vessels were recently observed in the fourth ventricle of the brain and in the spinal cord of a rat by using fluorescent nanoparticles. In order to quantify the nanoparticles in the primo vessels, we measured the florescence of the nanoparticles and calibrated the measurements by using a reference suspension. We removed the noise due to autofluorescence with the technique of multispectral imaging. The line densities of nanoparticles and the contrast values of their images were, respectively, 0.5 ± 0.5 ng/mm and 0.7 ± 0.5 for primo vessels in the fourth ventricle, and 1.3 ± 0.6 ng/mm and 1.4 ± 0.2 for primo vessels in the spinal cord. The data obtained from and the procedures used in this work could be useful in evaluating the feasibility of using nanoparticles as a contrast agent during MRI or CT imaging of primo vessels in the brain or the spinal cord. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

The Primo Vascular Structures Alongside Nervous System: Its Discovery and Functional Limitation

“…Therefore, DiI can bind to any cellular components containing phospholipids. Another technique to stain the primo structure is to use fluorescent nanoparticles composed of cobalt-ferrite embedded in silica shells with rhodamine B on a nanometer scale [4]. On the other hand, the mechanism by which nanoparticles stain specifically the primo vascular structures is unclear.…”

“…In the rat brain and spinal cord, the injection of fluorescent nanoparticles into the lateral ventricle stained the primo vessels floating in the cerebrospinal fluid of the 4th ventricle, as well as those lying alongside the blood vessels in the subarachnoid space in the dorsal surface of the spinal cord [4]. Similarly, the primo nodes and primo vessels on the arachnoid mater and primo node in the 4th ventricle of the rat brain were stained with trypan blue [5].…”

Primo Vascular System Floating in Lymph Ducts of Rats

“…(11) In order to enhance the lymph flow for efficient washing of AB, replace the moved internal organs to their original positions, close the outermost skin, and cover the rat's body with tissue paper three to four times to maintain body temperature. Put the rat on its back on a heating pad.…”

“…Since 2002, there have been an increasing number of reports on the PVS, which is composed of threadlike structures called primo vessels (PVs), thickened corpuscle-like parts called primo nodes (PNs), and a fluid flowing in the vessels. The PVS has been observed in various organs, such as the bloodstream [8,9], heart [10], and brain [11], and on the surfaces of internal organs such as the stomach, intestines, bladder, and liver [12,13]. The animals studied most often were mice, rats, and rabbits, and rarely pigs, dogs, and cows.…”

Review and Comment on the Relationship between Primo Vascular System and Meridians

“…The researchers isolated the floating PVs with diameters of 20~30  μ m from abdominal lymph vessels of rabbits by Alcian blue staining [37]. In the nervous system, PVS was not attached to the wall of the ventricle, but acted as a freely floating structure in the cerebrospinal fluid (CSF), and it ran along the central canal of the spinal cord by using fluorescent nanoparticles that were injected into the lateral ventricle [38]. Even on the surface of the internal organs, the PVs and PNs were not adhered to the surface of organs, but were floating in peritoneal fluid [39].…”