The study of possible application of sodium selenite as an adjuvant in lithium treatment: an effect on oxidative processes in heart of rats.

OBJECTIVE: Despite numerous side effects, including heart disturbances, lithium is still used in medicine. Selenium treatment can protect against toxicity of harmful substances and side effects of other drugs. In this study possibility of sodium selenite application as an adjuvant in lithium treatment was studied. MATERIALS AND METHODS: Male Wistar rats were treated with: control - saline; Li group - Li2CO3 (2.7 mg Li/kg b.w.); Se group - Na2SeO3 (0.5 mg Se/kg b.w.); Li+Se group simultaneously with Li2CO3 and Na2SeO3 (2.7 mg Li/kg b.w. and 0.5 mg Se/kg b.w., respectively) by stomach tube for a period of six weeks, once a day. In heart homogenates total antioxidant status (TAS), activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as concentrations of ascorbic acid (AA), reduced glutathione (GSH) and malonyldialdehyde (MDA) were determined. SOD/GPx, CAT/GPx and SOD/CAT ratios were evaluated. RESULTS: TAS was insignificantly increased, particularly in groups receiving selenium. GPx was slightly decreased in Li group and partially restored by Li+Se treatment. Selenium markedly enhanced AA concentration vs. CONTROL: MDA was increased significantly in Li and Se groups and restored in Li+Se treated. SOD/GPx and CAT/GPx. Ratios were slightly increased in Li group and restored by selenium co-administration. CONCLUSIONS: As Li+Se treatment resulted in no significant differences vs. control and restored MDA, SOD/GPx and CAT/GPx ratios. Research on selenium application during lithium therapy seems to be worth continuation.

The protective influence of selenium on oxidant disturbances in brain of rats exposed to lithium.

For more than sixty years lithium carbonate has been used in medicine. However, during its administration different side effects including oxidative stress can occur. Selenium belongs to essential elements possessing antioxidant properties. This study aimed at evaluating if selenium could be used as a protective adjuvant in lithium therapy. The experiment was performed on four groups of Wistar rats: I (control), II (Li), III (Se), IV (Li + Se) treated with saline, lithium carbonate (2.7 mg Li/kg b.w.), sodium selenite (0.5 mg Se/kg b.w.) and lithium carbonate (2.7 mg Li/kg b.w.) + sodium selenite (0.5 mg Se/kg b.w.), respectively. All substances were administered as water solutions by stomach tube for 3 or 6 weeks. Catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) as well as malonyldialdehyde (MDA) were determined in brain homogenates. Lithium slightly enhanced MDA and depressed CAT and SOD after 6 weeks as well as GPx after 3 weeks. Selenium co-administration showed tendency to restore the disturbed parameters. Selenium alone and given with lithium significantly increased GPx vs. Li-treated group after 3 weeks. Having regarded the outcomes of this study, the research on application of selenium during lithium treatment seems to be worth continuation.

Synthesis, physical properties and preliminary investigation of hemocompatibility of polyurethanes from aliphatic resources with castor oil participation.

The synthesis of polyurethanes (PURs) from oligoetherdiol, two low molecular diols, castor oil and 4,4'-Methylenebis(cyclohexylisocyanate) is described. These polymers are characterized by measurements of the mechanical bulk and surface properties, preliminary investigation of compatibility with human blood and calcification in static conditions. The critical surface energy of synthesized PURs is similar to the critical surface energy of natural surfaces. Material-induced hemolysis and the changes of platelet counts in blood samples after contact with PURs are very low. Static seven-weeks-calcification testing in a synthetic calcification fluid did not indicate calcification by optical density measurements and by visual inspection and computer image processing of the X-ray films for PURs with and without castor oil.

Neurohypophysial response to peptides of the cholecystokinin family: in vivo and in vitro studies.

I.c.v. injection of CCK-8 (50 ng/day) to euhydrated rats significantly decreased vasopressin and oxytocin content in the hypothalamo-neurohypophysial system. In rats drinking hypertonic saline and simultaneously treated with CCK-8, the decrease of vasopressin content was more marked in hypothalamus but somewhat restrained in the neurohypophysis. The decrease of hypothalamic and neurohypophysial oxytocin content (as brought about by the salt load) was significantly less marked in animals treated simultaneously with CCK-8. Incubation of neurointermediate lobes in medium enriched with CCK-33/CCK-39 or CCK-8 did not change significantly the vasopressin and oxytocin release from the neurointermediate lobes both under basal conditions and during potassium stimulation. It is suggested that afferent impulses of osmoreceptor origin may modify the response of vasopressinergic and oxytocinergic neurons to CCK-8. The events, related to the influence of CCK peptides on vasopressin or oxytocin release, do not seem to be localized at the neurohypophysial level.