A comparative evaluation of the effects on the crystallogenic properties of the rat blood serum for prolonged inhalations of nitric oxide or reactive oxygen species

Abstract

The objective of this work was to study how a prolonged course of inhalations of nitric oxide or singlet oxygen modify crystallization of the blood serum in rats. Experiments were performed with 50 adult Wistar rats, which were divided into five equal groups. The control group (n = 10) included intact rats, which were not exposed to any manipulation other than a single blood drawing. Rats of groups 2, 3, and 4 received inhalations of nitric oxide at 20, 50, and 100 ppm, respectively, daily for 30 days. Group 5 rats (n = 10) received a similar course of inhalations of singlet oxygen for 30 days. Blood samples were drawn from the sublingual vein in rats of the test groups immediately after completion of the inhalation course (day 30 of the experiment) and in the recovery period (day 60 of the experiment) and tested for crystallogenic activity. Dried samples were evaluated visually for crystallizability, structure index, facia destruction degree, and marginal zone clarity, using respective scales. A prolonged course of NO inhalations was found to modulate the crystallogenic properties of the rat serum. An optimal response was recorded at the lowest nitric oxide concentration (20 ppm). Higher NO concentrations caused more adverse changes in serum crystallization after the end of the inhalation course and hindered the recovery processes. Singlet oxygen inhalations for 30 days did not exert a considerable adverse effect on the crystallogenic properties of the rat serum.