Compares the distribution of the tanin asid as micromelecular trasser in the sheaths spinal cord and the peripheral nerves. electron microscopy research

Abstract

Aim. The aim of the current research consist using an electron microscope determination  diffusion of tannic acid, known as a micromolecular tracer, at the level of menings surrounding the spinal cord and peripheral nerves sheath after his application. 

Materials and methods. The experiment was given 10 mature white rats weighing from 200 to 260 grams. By introducing a 2.5% glutaraldehyde solution onto the ascending aorta, was given general fixation  of the studied animals. Postfixation of fragments of the spinal cord and sciatic nerve was performed in a 1% solution of osmium acid within 1 hour. Then, the studied fragments were immersed in a 1% solution of tannic acid prepared in 0.5 M cacodilate buffer (pH 7, 4) within 2 hours. Araldit-Epon və Spur blocks were prepared from the taken fragments according to the protocols used in electron microscopy. Ultrathin sections obtained from the latter were studied under a JEM-1400 electron microscope.

Rezults. The data obtained indicate that the applied 1% tannic acid solution is transported by the collagen fibers themselves and by the intestinal compounds.    It should be noted that although the interstitial substance is not colored in areas containing hyaluronic acid, fine, osmifil tannic acid granules are detected at the level of the glycosaminglicans. In both the spinal cord and the sciatic nerves, tannic acid is transported to the level of structures that play a biological barrier.

Therefore, the location of the tracer is separated by a single layer of arachnoidal and perineural barrier cells, respectively, from the cerebrospinal and endoneural fluids. Thus, accumulation of ions with osmotic activity at the level of biological barriers can provide transport of the cerebrospinal and endoneural fluids in the direction of  the sheaths that surround them.