REACTIVE OXYGEN SPECIES GENERATION BY BLOOD LEUCOCYTES OF RATS WITH POLYCYSTIC OVARY SYNDROME UNDER THE CONDITIONS OF INTERMITTENT COLD EXPOSURE.

OBJECTIVE: The aim of this study was to determine the level of ROS production by blood leukocytes of rats with PCOS under the conditions of intermittent cold exposure. PATIENTS AND METHODS: Materials and methods: In the study, 40 immature female rats of the WAG population at the age of 27 days with a body weight of 80-90 g were used. Five groups were formed (8 animals in each group). Group 1 was represented by intact rats that were not subjected to any manipulations. Group 2 was represented by rats that were injected subcutaneously with 0.2 ml of purified and sterilized olive oil daily for 25 days. Group 3 was represented by rats that were exposed to intermittent cold for 25 days. Group 4 was represented by rats that were modeled with PCOS. Group 5 was represented by rats, which were simulated PCOS against the background of intermittent cold exposure. ROS production was estimated in leukocytes isolated from rats of all groups by flow cytometry using the fluorescent probe of 2,7-dichlorodihydrofluorescein diacetate (H2DCFDA). RESULTS: Results: The experimental study revealed an intracellular excessive production of ROS by leukocytes in rats with polycystic ovary syndrome. The use of inter¬mittent cold exposure normalized the production of reactive oxygen species by leukocytes in rats with polycystic ovary syndrome. CONCLUSION: Conclusions: The effectiveness of intermittent cold exposure, proven by the authors, allows recommending its use as one of the methods of prevention and treatment of the polycystic ovary syndrome.

Semi-refined carrageenan promotes generation of reactive oxygen species in leukocytes of rats upon oral exposure but not in vitro.

AIM: To assess the ability of the common food additive E407a (semi-refined carrageenan) to enter leukocytes in vitro and generate reactive oxygen species (ROS) in leukocytes as a whole and granulocytes in particular, both during incubation and in experimental animals. METHODS: ROS production was assessed in leukocytes incubated with E407a for 2 h at the final concentrations of 5 and 10 g/L using the dye 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA), as well as in cells isolated from rats orally exposed to E407a (140 mg/kg of weight) during 2 weeks (n = 8) and control rats (n = 8), by flow cytometry. Carrageenan uptake by leukocytes was estimated by confocal microscopy using incubation of rhodamine B isothiocyanate-labelled carrageenan with leukocyte suspensions. RESULTS: Uptake of carrageenan by viable neutrophils, monocytes, and lymphocytes was confirmed. Oral administration of the food additive E407a was associated with excessive ROS formation by viable leukocytes (CD45+, 7­aminoactinomycin D- cells) and especially in granulocytes. Unexpectedly, a direct impact of semi-refined carrageenan during incubation for 2 h did not affect ROS production in leukocytes, evidenced by statistically insignificant differences in mean fluorescence intensity values of 2',7'-dichlorofluorescein, which is a ROS-sensitive product of intracellular H2DCFDA conversion. Oral intake of E407a and direct exposure of leukocyte suspensions to it decreased the viability of leukocytes. CONCLUSION: Food-grade carrageenan can enter leukocytes without affecting ROS generation as a result of incubation for 2 h with leukocyte suspensions. On the contrary, oral exposure to E407a is accompanied by ROS overproduction by white blood cells, suggesting an indirect mechanism for the stimulation of ROS synthesis in vivo. E407a promotes cell death of leukocytes both in vivo and in vitro.

Experimental Evaluation of the Impact of Gadolinium Orthovanadate GdVO4:Eu3+ Nanoparticles on the Carrageenan-Induced Intestinal Inflammation.

AIM: To evaluate the effects of orally administered gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) on the course of chronic carrageenan-induced intestinal inflammation. METHODS: Samples of small intestinal tissue were collected from four groups of rats (intact, after administration of VNPs, with carrageenaninduced intestinal inflammation, with carrageenan-induced intestinal inflammation orally exposed to VNPs) to assess the intestinal morphology and HSP90α expression. Levels of seromucoid, C-reactive protein, TNF-α, IL-1ß and IL-10 were determined in blood serum. RESULTS: Oral exposure to VNPs was associated with neither elevation of inflammation markers in blood serum nor HSP90α overexpression in the small intestine, i.e. no toxic effects of VNPs were observed. Carrageenan-induced intestinal inflammation was accompanied by higher levels of TNF-α and IL-1ß, as well as HSP90α upregulation in the intestinal mucosa, compared with controls. Administration of VNPs to rats with enteritis did not lead to statistically significant changes in concentrations of circulating pro-inflammatory cytokines with the trend towards their increase. CONCLUSION: No adverse effects were observed in rats orally exposed to VNPs at a dose of 20 µg/kg during two weeks. Using the experimental model of carrageenan-induced enteritis, it was demonstrated that VNPs at the dose used in our study did not affect the course of intestinal inflammation.