We studied the effect of human lactoferrin (hLf) on degenerative changes in the nigrostriatal system and associated behavioral deficits in the animal model of Parkinson disease. Nigrostriatal dopaminergic injury was induced by single administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 40 mg/kg) to five-month-old C57Bl/6 mice. Behavioral disturbances were assessed in the open field and rotarod tests and by the stride length analysis. Structural deficits were assessed by the counts of tyrosine hydroxylase (TH)-immunoreactive neurons in the substantia nigra and optical density (OD) of TH-immunolabeled fibers in the striatum. Acute MPTP treatment induced long-term behavioral deficit and degenerative changes in the nigrostriatal system. Pretreatment with hLf prevented body weight loss and promoted recovery of motor functions and exploratory behavior. Importantly, OD of TH-positive fibers in the striatum of mice treated with hLf almost returned to normal, and the number of TH-positive cells in the substantia nigra significantly increased on day 28. These results indicate that hLf produces a neuroprotective effect and probably stimulates neuroregeneration under conditions of MPTP toxicity in our model. A relationship between behavioral deficits and nigrostriatal system disturbances at delayed terms after MPTP administration was found.

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We studied the effects of human lactoferrin (hLf), a multifunctional protein from the transferrin family, on integral (survival, lifespan during the experiment, body weight, behavior, subfractional compositions of blood serum) and systemic (hemoglobin level, leukocyte number, differential leukocyte count, histological structure of the liver and spleen) parameters of the body in mice after acute gamma irradiation in a sublethal dose. The experiments were performed on male C57BL/6 mice. The mice in the experimental groups were exposed to whole-body gamma radiation in a dose of 7.5 Gy from a 60Co source. Immediately after irradiation and 24 h after it, some animals received an intraperitoneal injection of hLf (4 mg/mouse). Single or repeated administration of hLf had a positive pleiotropic effect on irradiated animals: animal survival increased from 28% to 78%, and the mean life expectancy during the experiment (30 days) increased from 16 to 26 days. A compensatory effect of hLf on radiation-induced body weight loss, changes in homeostasis parameters, and a protective effect on the structural organization of the spleen were demonstrated. These data indicate that Lf has potential as a means of early therapy after radiation exposure.

Objectives: A method of continuous heart rate (HR) and blood pressure (BP) recording was used for the evaluation of the cardiovascular system parameters in participants of short-term (<1 month) high-latitude expeditions, in comparison with the parameters of residents of Central Russia and the Arctic region. Material and Methods: A dynamic examination of participants of Arctic expeditions (30 men, residents of middle-latitude regions, aged 46.7±1.7 years), workers permanently living in Central Russia (the Moscow region, 44 men, aged 46.7±1.0 years) and residents of the North (the Murmansk region, 35 men, aged 46.6±1.3 years) was performed. The authors used a spiroartheriocardiorythmograph allowing the parallel recording of HR, BP, spectral characteristics of HR variability (HRV) and the variability of systolic BP (sBP) and diastolic BP (dBP), cardiac performance parameters, and spontaneous baroreflex sensitivity (BRS). The parameters were recorded at rest, in a sitting position, over 2 min. Results: The basic clinical parameters (HR, BP and cardiac performance) did not differ in the workers living in different climatic zones. However, the residents of the North demonstrated a lower total power (TP) of the dBP variability spectrum and a lower relative power of the high-frequency (HF) range in both the sBP and dBP variability spectra. The participants of expeditions to the North had a lower TP of the HRV spectrum (in comparison with both control groups) that did not change during the expeditions; BRS was reduced, while the TP of the sBP spectrum was increased in comparison with the corresponding parameters obtained from the residents of circumpolar regions, and decreased during the expedition in parallel with a decrease in the sBP values. The TP of both the sBP and dBP variability spectra, as well as the power of the HF range in these spectra, were similar in the participants of expeditions to those obtained from the residents of Central Russia, and they considerably surpassed the corresponding parameters in the northerners surveyed. Conclusions: The revealed peculiarities of the cardiovascular system in the participants of high-latitude expeditions can be considered as correlates of positive, and adequate in terms of the physiological value, adaptive shifts in the autonomous regulation of the cardiovascular system.

Changes in cardiovascular system (CVS) under conditions of hypogravity simulated using 7-and 21-day ortho-and antiorthostatic hypokinesia at different angles were studied. The aim of the experiment was selection of informative CVS parameters most sensitive to these conditions. Simultaneous recording of 26 CVS parameters on a spiroartheriocardiorythmograph showed that the most sensitive parameters were blood pressure (BP) variability indexes in functional tests: differences in groups with varying degrees of orthostatic hypokinesia (+ 9.6˚ and + 15˚) were observed starting from the first week of the experiment. By day 21, pronounced changes in the total spectral power of diastolic BP variability were noted in the group exposed to constant antiorthostasis. This parameter significantly surpassed the corresponding value in the groups with milder conditions. Significant increase in the LF component of diastolic BP in groups exposed to severe antiorthostasis and orthostasis was detected. Presumably, autonomic mechanisms affecting the systolic and diastolic BP under conditions of hypogravity simulation are different, at least partially.