MORPHOLOGICAL CHARACTERISTICS OF THE MICROVASCULATURE OF DURA MATER OF BRAIN IN THE DYNAMICS OF CHRONIC NITRITE INTOXICATION OF AN ORGANISM
On 60 white outbred rats of both sexes weighing 180-200 g, a model of chronic nitrite intoxication of the body was reproduced by oral administration of an aqueous solution of sodium nitrite at a dose of 17 mg/kg for 3 months (N. I. Bulayeva, 2004). The control group consisted of 10 animals that received ordinary water. Under ketamine anesthesia, every month the rats were sacrificed by decapitation (15 each). Total fragments of the dura mater of brain were impregnated according to V.V. Kupriyanov (1975). Analysis of the microvasculature was carried out with morphometry of the diameter of microvessels using an eyepiece micrometer. The quantitative data were processed statistically, with an assessment of the Student’s t-test. Microvasculature of dura mater of brain of intact animals is represented by a wide-mesh network formed by anastomoses of arterioles (A) and venules (V), which had even contours and a rectilinear course. Diameter A is on average 21 microns, V - 37 microns. In order to objectify the diameter of microvessels in the dynamics of intoxication, in the intact group, they are divided into 2 morphometric classes: 1<sup>st</sup> class - small and 2<sup>nd</sup> class - large. After 1-2-3 months of chronic inoculation with sodium nitrite in dura mater of brain, signs of progressive vasodilation, tortuosity, argyrophilia of the microvasculature walls are revealed with the appearance of atypically large (3<sup>rd</sup> morphometric class) microvessels, in which signs of edema and cell infiltration are noted. Conclusions. Thus, 1<sup>st</sup> month after chronic inoculation with sodium nitrite, violations of the microvasculature of dura mater of brain are characterized by plethora of all links of the channel, maximum by the 3<sup>rd</sup> month, an increase in their permeability with the formation of perivascular edema, stasis, and blood aggregation. The results of the study can be useful in deciphering the pathogenetic mechanisms of chronic nitrite intoxication and used in the selection of therapy.