Levels of selenium in the rat pineal gland: the effects of selenium supplementation

Levels of selenium (Se) were measured in the pineal glands of rats aged 4,5,8 and 12 months and the following corresponding levels of Se were determined: 1.058 nmol/gland, 0.63 nmol/gland, 0.58 nmol/gland and 0.43 nmol/gland. In the rat pineal glands obtained from rats which drank water containing Se coupled to brewers yeast (average daily intake of Se per animal was 0.5µg ) the following increased levels of Se were determined: 0.87 nmol/gland, 0.72 nmol/gland and 0.59 nmol/gland at the ages of 5,8 and 12 monthsrespectively. Since Se participates in the antioxidative defense of the mammalian organism, the increased levels of Se in the pineal glands of rats supplemented with Se in drinking water, may be of physiological benefit during ageing.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effect of EDTA on the inhibition of rat myometrial ecto-atpase activity in the presence of heavy metal ions I. Mercury

The effects of increasing concentrations of HgCl2 on rat uterine plasma membrane ecto-ATPase activity, in presence and absence of ethylenediamine tetra acetic acid (EDTA) were studied. The aim was to examine the ability of EDTA to prevent mercury induced inhibition of ecto-ATPase activity. Our results show that addition of 1mmol/l EDTA to the reaction mixture potentiates Hg2+ induced inhibition of enzyme activity. We may concluded that formation of the HgEDTA complex increased capacity of Hg2+ to inhibit enzyme activity.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Different sensibility of ecto-ATPase from brain and ovary to Cu2+ and Zn2+

Ions of zinc and cooper represents micro elements present in all organisms but they can be accumulated in various tissues from the environment by food or pollution. In this work we examined the effects of chloride salts of Cu2+ and Zn2+ on the activity of ecto-ATPase, integral plasma membrane protein, in brain and ovarian cells. Both ions exhibit similar effects on brain or ovarian enzyme activity. Cooper in brain and ovary totally inhibits enzyme activity at the concentration of 1 mM and 0.1 M respectively. IC50 for brain is 36 µM while in ovary it is 192 µM. Zinc inhibits in both tissues 50% of the control enzyme activity at concentrations of 1 mM in brain and 0.1 M in ovary with IC50 of 1mM and 14 mM respectively. These metals possess an affinity for -SH groups in the enzyme protein, may replace Mg2+ in enzyme substrate, MgATP or to bind for enzyme substrate site. According to the total inhibition of ecto-ATPase activity by Cu 2+, it may be proposed that its site of action is on the substrate or substrate binding site, while Zn2+ modulates enzyme activity by acting on the –SH or S-S groups of the enzyme. Inhibiting or decreasing ecto-ATPase activity in brain and ovary, these two metal ions may be toxic and seriously disturb the proper functioning of the investigated tissues.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effect of EDTA on the inhibition of rat myometrial ecto-ATPase activity in the presence of heavy metal ions II. cadmium

The effects of ethylenediamine tetraacetic acid (EDTA) on the CdCl2 cell toxicity was examined on rat myometrium. Activity of plasma membrane ecto-ATPase, as modulator of purinergic signaling in the presence of increasing concentrations of cadmium salt and in the presence or absence of EDTA were studied. The EDTA, chelating cadmium ions decrease inhibitory cadmium potency by increasing half-maximum inhibitory activities of this ion.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Calcium (Ca2+) content in the lower jaws of rats irradiated in the head region with X-rays

ct Irradiating the head region of 8-day-old rats with a dose of 8.64Gy of X-rays, at the age of 42 days, results in stunting of lower jaw growth as illustrated by measuring the length and height of the jaws. This irradiation dose also has as a consequence an increased content of Ca 2+ in the bone tissue of the lower jaw (270.36±27.97 mmol/kg bone tissue) when compared to the corresponding non-irradiated controls (188.58±19.26 mmol/kg bone tissue, p<0.05) and rats irradiated with a dose of 3.84Gy of X-rays (143.99±15.29 mmol/kg bone tissue, p<0.01).Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effects of nitric oxide production on glutathione levels in an animal model of depression

Stimulation of glutamate receptors induces neuronal nitric oxide (NO) release, which in turn modulates glutamate transmission. The present study evaluated the effects of acute, chronic or combined stress on NO production via the accumulation of nitrite, the stable metabolite of NO, in the prefrontal cortex and hippocampus of male Wistar rats. Given that glutathione (GSH) plays a critical role in protecting cells from oxidative stress, as well as maintaining the thiol redox state, GSH levels in cytosolic fractions of both brain structures were examined. A significant increase in nitrite levels was obtained after 3 weeks of chronic isolation stress, followed by combined stresses (chronic + acute stress). Moreover, GSH levels were significantly decreased after chronic and both combined stresses in both brain structures. Our data support the idea that GSH might represent an important buffer of NO toxicity in the brain, indicating that compromised redox buffering controlled by GSH makes neuronal cells susceptible to endogenous physiological flux of NO.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Nitric oxide and protein carbonyl content in the liver of stressed rats

Nitric oxide (NO) has been identified as a source of oxidative/nitrosative stress that is known to oxidatively modify DNA, lipids and proteins. One such modification is the addition of carbonyl groups to amino acid residues in proteins. Therefore, the aim of our study was to examine the effects of acute, chronic or combined stress on NO production and protein carbonyl content in the cytosolic fraction of rat liver. Since NO is a highly reactive molecule, the levels of NO metabolites (nitrates and nitrites) as markers of stable end products of NO metabolism were measured. Both acute stresses showed unchanged nitrite levels while only acute IM stress led to an increased level of the carbonyl group. The NO metabolites and protein carbonyl content were increased by chronic isolation and remained upregulated after combined stress. These data indicate that chronic isolation stress with increased NO metabolites led to nitrosative stress, whereby accumulation of oxidized proteins in the liver may induce progressive liver damage.Physical chemistry 2012 : 11th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 201

Different induction of dual corticosteroid receptor system in the rat hippocampus following gamma radiation

Cranial radiotherapy (CRT) is an effective way to prevent CNS relapse in children with acute lymphoblastic leukemia (ALL). However, CRT also has serious side effects on normal tissues, including long-term neuroendocrine disturbances. In order to test this clinical protocol on animals, we examined the effects of CRT (10 Gy) on the level of mRNA for glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) in the hippocampus of 8-days-old rats. Irradiation rapidly stimulated GR gene expression in a time-dependent manner, whereas the time-course of MR mRNA expression showed no statistically significant changes. At postnatal day 42, the level of GR mRNA was diminished while the level of MR mRNA remained unchanged compared to matched controls. Dexamethasone suppression test (DST) revealed the altered nucleocytoplasmic shuttling of activated GR after CRT in 42-days-old rats, as a long-term consequence of gamma irradiation.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Optimizacija metode za izolaciju epitelnih stanica iz nežljezdanog dijela želuca štakora za protočnu citometriju

Traditional methods in cell proliferation studies are based on immunohistochemical detection of proliferating cells in the target tissue. Since they are time consuming, optimization of novel, more efficient methods is important for large scale proliferation studies. In this study, we aimed to optimize the isolation of single epithelial rat forestomach cells for flow cytometry. As a marker of cellular proliferation we used the Ki-67 antibody to detect this nuclear protein expressed in proliferating cells. We also performed immunohistochemical detection of Ki-67 positive cells and propidium iodide staining to validate the results. 3-tert- butyl -4-hydroxyanisole was used as the positive control to ensure cellular proliferation. The results showed that isolation of epithelial cells with collagenase, trypsin and cell strainer ensures great cell viability (>95%) and the purity of the samples. Flow cytometry and immunostaining with the Ki-67 antibody indicated that 3-tert- butyl-4-hydroxyanisole treatment leads to a significant increase in proliferation. A significant positive correlation was observed between the results obtained by immunohistochemistry and flow cytometry, but the flow cytometric data had a smaller measurement error, suggesting the equal sensitivity and greater accuracy of this method. Propidium iodide staining showed that the percentage of cells in the G2+S phase of the cell cycle correlated positively with the percentage of Ki-67 positive cells assessed by flow cytometry, indicating that Ki-67 positive cells reflect an active dividing cell pool. We conclude that the isolation of forestomach epithelial cells described is a simple and reliable method for obtaining viable cells for use in flow cytometry. Compared to immunohistochemistry, flow cytometric detection of the Ki-67 antigen is equally sensitive, but much faster and provides more accurate results.Tradicionalne metode u ispitivanju stanične proliferacije temelje se na imunohistokemijskom otkrivanju proliferacijskih stanica u ciljanom tkivu. Kako su dugotrajne, optimizacija novih i učinkovitijih metoda važna je za velika istraživanja o proliferaciji. U ovom smo radu željeli optimizirati izolaciju epitelnih stanica prednjeg želuca štakora za protočnu citometriju. Kao marker stanične proliferacije koristili smo Ki-67 protutijelo za otkrivanje ovoga nuklearnog proteina izraženog u proliferacijskim stanicama. Također smo učinili imunohistokemijsku detekciju Ki- 67 pozitivnih stanica i bojenje propidij-jodidom kako bismo potvrdili rezultate. Butil-hidroksianizol korišten je kao pozitivna kontrola da se osigura stanična proliferacija. Rezultati su pokazali da izolacija epitelnih stanica s kolagenazom, tripsinom i staničnim cjedilom osigurava veliku vijabilnost stanica (> 95 %) i čistoću uzoraka. Protočna citometrija i Ki-67 bojenje pokazali su da tretman butil-hidroksianizolom dovodi do znakovitog porasta proliferacije. Primijećena je znakovita pozitivna korelacija između rezultata dobivenih imunohistokemijom i protočnom citometrijom, dok su protočni citometrijski podaci imali manju pogrešku mjerenja, što upućuje na jednaku osjetljivost i veću točnost ove metode. Bojenje propidij-jodidom pokazalo je da postotak stanica u G2+S fazi staničnog ciklusa pozitivno korelira s postotkom Ki-67 pozitivnih stanica procijenjenih protočnom citometrijom, što upućuje na to da Ki-67 oslikava stanice u aktivnoj diobi. Zaključujemo da je opisana izolacija epitelnih stanica prednjeg želuca štakora jednostavna i pouzdana metoda za dobivanje održivih stanica za upotrebu u protočnoj citometriji. U usporedbi s imunohistokemijom, protočna citometrijska detekcija antigena Ki-67 jednako je osjetljiva, ali mnogo brža i daje točnije rezultate

Inactivation of melanoma cells irradiated with gamma rays and low energy protons

13th Balkan biochemical Biophysical Days and Meeting on Metabolic Disorders, October 12.-15., 2003, Kusadasi, Turke