The Effects of Zinc Treatment on the Blood–Brain Barrier Permeability and Brain Element Levels During Convulsions

We evaluated the effect of zinc treatment on the blood–brain barrier (BBB) permeability and the levels of zinc (Zn), natrium (Na), magnesium (Mg), and copper (Cu) in the brain tissue during epileptic seizures. The Wistar albino rats were divided into four groups, each as follows: (1) control group, (2) pentylenetetrazole (PTZ) group: rats treated with PTZ to induce seizures, (3) Zn group: rats treated with ZnCl₂ added to drinking water for 2 months, and (4) Zn?+?PTZ group. The brains were divided into left, right hemispheres, and cerebellum?+?brain stem regions. Evans blue was used as BBB tracer. Element concentrations were analyzed by inductively coupled plasma optical emission spectroscopy. The BBB permeability has been found to be increased in all experimental groups (p?<?0.05). Zn concentrations in all brain regions in Zn-supplemented groups (p?<?0.05) showed an increase. BBB permeability and Zn level in cerebellum?+?brain stem region were significantly high compared to cerebral hemispheres (p?<?0.05). In all experimental groups, Cu concentration decreased, whereas Na concentrations showed an increase (p?<?0.05). Mg content in all the brain regions decreased in the Zn group and Zn?+?PTZ groups compared to other groups (p?<?0.001). We also found that all elements’ levels showed hemispheric differences in all groups. During convulsions, Zn treatment did not show any protective effect on BBB permeability. Chronic Zn treatment decreased Mg and Cu concentration and increased Na levels in the brain tissue. Our results indicated that Zn treatment showed proconvulsant activity and increased BBB permeability, possibly changing prooxidant/antioxidant balance and neuronal excitability during seizures.     

Effects of Zinc Glycinate on Productive and Reproductive Performance,Zinc Concentration and Antioxidant Status in Broiler Breeders

An experiment was conducted to investigate the effects of zinc glycinate (Zn-Gly) supplementation as an alternative for zinc sulphate (ZnSO₄) on productive and reproductive performance, zinc (Zn) concentration and antioxidant status in broiler breeders. Six hundred 39-week-old Lingnan Yellow broiler breeders were randomly assigned to 6 groups consisting of 4 replicates with 25 birds each. Breeders were fed a basal diet (control group, 24 mg Zn/kg diet), basal diet supplemented with 80 mg Zn/kg diet from ZnSO₄ or basal diet supplemented with 20, 40, 60 and 80 mg Zn/kg diet from Zn-Gly. The experiment lasted for 8 weeks after a 4-week pre-test with the basal diet, respectively. Results showed that Zn supplementation, regardless of sources, improved (P?<?0.05) the feed conversion ratio (kilogram of feed/kilogram of egg) and decreased broken egg rate, and elevated (P?<?0.05) the qualified chick rate. Compared with the ZnSO₄ group, the 80 mg Zn/kg Zn-Gly group significantly increased (P?<?0.05) average egg weight, fertility, hatchability and qualified chick rate, whereas it decreased (P?<?0.05) broken egg rate. The Zn concentrations in liver and muscle were significantly higher (P?<?0.05) in 80 mg Zn/kg Zn-Gly group than that in ZnSO₄ group. Compared with ZnSO₄ group, 80 mg Zn/kg Zn-Gly group significantly elevated (P?<?0.05) the mRNA abundances of metallothionein (MT) and copper-zinc superoxide (Cu-Zn SOD), as well as the Cu-Zn SOD activity and MT concentration in liver. Moreover, the 80 mg Zn/kg Zn-Gly group had higher (P?<?0.05) serum T-SOD and Cu-Zn SOD activities than that in the ZnSO₄ group. This study indicated that supplementation of Zn in basal diet improved productive and reproductive performance, Zn concentration and antioxidant status in broiler breeders, and the 80 mg Zn/kg from Zn-Gly was the optimum choice for broiler breeders compared with other levels of Zn from Zn-Gly and 80 mg/kg Zn from ZnSO₄.     

Effects of Zinc Supplement on Plasma Homocysteine Level in End-Stage Renal Disease Patients: a Double-Blind Randomized Clinical Trial

Increased homocysteine (hCys) level is an independent risk factor for cardiovascular complications in end-stage renal disease (ESRD) patients. The aim of this study was to evaluate effect of zinc (Zn) supplement on serum hCys level in ESRD patients. One hundred ESRD patients with Zn deficiency were enrolled in this double-blind randomized clinical trial. They were randomly subdivided into two groups and supplemented with Zn (Zn group) or placebo (control group) for 6 weeks. Fasting plasma hCys and Zn levels were measured before and at 43rd days after the start of the study. Serum Zn levels increased significantly (p?<?0.0001), in Zn-treated group in comparison to placebo-treated group. In the Zn-treated group, serum hCys levels reduced significantly (p?<?0.0001), compared to placebo group (p?>?0.05). There was a significant (p?<?0.0001) reduction of mean percentage of hCys in Zn-treated group compared to the placebo group. Our study showed that Zn supplementation decreases serum hCys levels in ESRD patients with Zn deficiency.     

Effects of High Zinc Levels on the Lipid Synthesis in Rat Hepatocytes

Zinc deficiency impairs the hepatic lipid metabolism. Previous studies were focused on the negative effects of zinc deficiency on the hepatic lipid metabolism. A few studies investigated the effects of high zinc levels on the lipid metabolism in hepatocytes. In this study, rat hepatocytes were cultured and treated with different and high concentrations of zinc to investigate the effects of high zinc levels on the lipid synthesis in hepatocytes in vitro. The levels of hepatocytes functional markers, including alkaline phosphatase, lactate dehydrogenase, and albumin, were significantly higher in the zinc treatment groups than in the control group (p?<?0.05, p?<?0.01). The mRNA and protein levels of sterol regulatory element-binding protein 1c (SREBP-1c) were significantly higher in the zinc treatment groups than in the control group (p?<?0.05, p?<?0.01). Furthermore, the mRNA expression levels of acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) were significantly higher in the medium- and high-dose zinc treatment groups than in the control group (p?<?0.01). The mRNA levels of stearoyl-CoA desaturase-1 (SCD-1) were significantly higher in the high-dose group (p?<?0.01). These results indicate that high levels of zinc increase hepatocytes activity and SREBP-1c expression, which upregulate the expression of ACC1, FAS, and SCD-1, thereby improving the lipid metabolism in the hepatocytes.     

Effects of Dietary Zinc and l-Arginine Supplementation on Total Antioxidants Capacity, Lipid Peroxidation, Nitric Oxide, Egg Weight, and Blood Biochemical Values in Japanase Quails

The aim of this study was to evaluate effects of dietary zinc and l-arginine supplementation on blood total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), some blood chemistry parameters, and egg weights of laying quails. Three groups of Japanese quails were fed with a diet containing l-arginine (5 mg/kg), zinc (60 mg/kg), and normal basal diet (control) for 30 days. TAC, lipid peroxidation, and biochemical analysis were performed in the blood of animals. l-Arginine and zinc supplementation improved TAC and reduced MDA concentrations compared to the control (P?<?0.05). In comparison to the control, blood NO concentrations were increased by l-arginine (P?<?0.01) and zinc treatment (P?<?0.05). Both zinc (P?<?0.001) and l-arginine (P?<?0.01) supplementation significantly increased egg weight in laying quails. Some of the blood chemistry parameters were also altered by the treatment of l-arginine and zinc supplementation. No difference was found in blood albumin and creatinine levels among the groups. Blood glucose (P?=?0.833) and total protein (P?=?0.264) levels in control and l-arginine-treated groups were found to be similar. Glucose and total protein levels were decreased in zinc-supplemented animals compared to the control and l-arginine groups (P?<?0.05). No difference was found in triglyceride levels between control and zinc-applied groups (P?=?0.197). However, l-arginine treatment reduced the blood triglyceride levels compared to the control (P?<?0.05). In conclusion, l-arginine and zinc supplementation could be beneficial and effective for decreasing oxidative stress, boosting antioxidant capacity, and improving egg weight in the blood of the animals.     

Selenium, Zinc, and Copper Plasma Levels in Patients with Schizophrenia: Relationship with Metabolic Risk Factors

The aim of this study was to determine the plasma selenium (Se), copper (Cu), and zinc (Zn) levels and to evaluate their possible association with metabolic syndrome (MetS) components in patients with schizophrenia. The study group consisted of 60 patients with schizophrenia and 60 sex- and age-matched healthy controls. Anthropometric measurements, blood pressure, and biochemical analysis of fasting blood were performed in all subjects. Patients with schizophrenia had significantly higher plasma Cu concentrations compared with controls (0.97?±?0.31 vs. 0.77?±?0.32 mg/L, p?=?0.001). The plasma Cu concentration showed a positive correlation with plasma glucose and diastolic blood pressure in the patient groups (r _s ?=?0.263, p?<?0.05 and r _s ?=?0.272, p?<?0.05, respectively). The plasma Se level correlated positive with MetS score (r _s ?=?0.385, p?<?0.01), waist circumference (r _s ?=?0.344, p?<?0.05), plasma glucose (r _s ?=?0.319, p?<?0.05), and triglyceride concentrations (r _s ?=?0.462, p?<?0.001) in patients with schizophrenia. Plasma Zn did not correlate with any of the MetS components. These results suggest that alterations in plasma Cu and Se levels in medicated patients with schizophrenia could be associated with metabolic risk factors.     

Effects of Selenium and L-Carnitine on Oxidative Stress in Blood of Rat Induced by 2.45-GHz Radiation from Wireless Devices

The levels of blood lipid peroxidation, glutathione peroxidase, reduced glutathione, and vitamin C were used to follow the level of oxidative damage caused by 2.45 GHz electromagnetic radiation in rats. The possible protective effects of selenium and L-carnitine were also tested and compared to untreated controls. Thirty male Wistar Albino rats were equally divided into five groups, namely Groups A₁ and A₂: controls and sham controls, respectively; Group B: EMR; Group C: EMR + selenium, Group D: EMR + L-carnitine. Groups B–D were exposed to 2.45 GHz electromagnetic radiation during 60 min/day for 28 days. The lipid peroxidation levels in plasma and erythrocytes were significantly higher in group B than in groups A₁ and A₂ (p?<?0.05), although the reduced glutathione and glutathione peroxidase values were slightly lower in erythrocytes of group B compared to groups A₁ and A₂. The plasma lipid peroxidation level in group A₂ was significantly lower than in group B (p?<?0.05). Erythrocyte reduced glutathione levels (p?<?0.01) in group B; erythrocyte glutathione peroxidase activity in group A₂ (p?<?0.05), group B (p?<?0.001), and group C (p?<?0.05) were found to be lower than in group D. In conclusion, 2.45 GHz electromagnetic radiation caused oxidative stress in blood of rat. L-carnitine seems to have protective effects on the 2.45-GHz-induced blood toxicity by inhibiting free radical supporting antioxidant redox system although selenium has no effect on the investigated values.     

Copper and Resveratrol Attenuates Serum Catalase, Glutathione Peroxidase, and Element Values in Rats with DMBA-Induced Mammary Carcinogenesis

In this paper, a hypothesis was assessed whether or not the intoxication with copper and supplementation with copper plus resveratrol would result in changes in the activities of catalase and glutathione peroxidase and moreover if the characteristic changes would appear in concentrations of copper, iron, calcium, magnesium, and zinc in the serum of rats with chemically induced carcinogenesis. Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet, were treated with copper (42.6 mg Cu/kg food as CuSO₄·5H₂O) or copper plus resveratrol (0.2 mg/kg body) via gavage for a period from 40 days until 20 weeks of age. In cancer groups, the rats were treated with a dose of 80 mg/body weight of 7,12-dimethyl-1,2-benz[a]anthracene (DMBA) given in rapeseed oil at 50 and 80 days of age to induce mammary carcinogenesis. The control groups included the rats kept in the same conditions and fed with the same diet as the animals from the study groups, but not DMBA-treated. The activity of catalase significantly decreased in groups of rats with mammary carcinogenesis that were supplemented with copper (p?<?0.05) or copper plus resveratrol (p?<?0.001) in comparison with the control groups that received the same diets. In cancer groups of nonsupplemented rats, the increase of glutathione peroxidase activity was observed. The process of carcinogenesis and the applied supplementation significantly altered the concentrations of trace elements in serum, in particular as concerns iron and copper. The mean serum iron levels in rats with breast cancer were significantly lower than those in the control groups (p?<?0.001). The mean serum copper levels significantly decreased in the groups of rats with mammary carcinogenesis that were supplemented with copper or copper plus resveratrol in comparison with the control groups that received the same diets (p?<?0.001). The characteristic changes in iron content and the zinc/copper and zinc/iron ratios in blood may be used as one of the prognostic factors in breast cancer research.     

Alteration of Plasma Trace Elements in Patients Undergoing Open Heart Surgery

Trace elements may contribute to myocardial dysfunction and susceptibility of the phospholipid cell membrane to free-radical damage and oxidative changes. We studied the concentration of trace elements copper, zinc, and magnesium in cardiac surgery. Fifty-four consecutive patients for elective coronary artery bypass grafting (n?=?30) and valve replacement (n?=?24) were studied. Blood samples were collected every 30 min (T1–T5) during cardiopulmonary bypass and postoperatively (T6–T9). Plasma concentrations of copper, zinc, and magnesium were measured with flame atomic absorption spectrophotometry. The concentrations of copper, zinc, and magnesium were significantly different during and after cardiopulmonary bypass (p?<?0.01). The zinc concentration at T7 and T8 (p?<?0.01) and the copper concentration at T1, T9 (p?<?0.05) were significantly different between two groups. However, the magnesium concentration had no significant differences between the two groups (p?>?0.05). In patients undergoing valve replacement or coronary artery bypass grafting, the concentrations of copper and zinc decreased significantly during cardiopulmonary bypass. Our study suggests that the current cardiopulmonary bypass protocol is adequate in the maintenance of c magnesium. However, the low copper and zinc concentrations found in the present study may suggest that in the future, supplementation particularly of copper and zinc may become a necessary procedure in cardiac surgery with cardiopulmonary bypass.     

The evaluation of protective and mitigating effects of vitamin C against side effects induced by radioiodine therapy

The goal of this study was to evaluate the protective and mitigative effect of vitamin C on oxidative stress in differentiated thyroid cancer (DTC) patients ablated with radioiodine. 58 DTC patients selected for radioactive iodine therapy (RAIT) with 5550 MBq ¹³¹Iodine were divided into four groups. Group 1 (control group) consisted of patients who underwent RAIT routinely. Other patients received 1500 mg vitamin C daily 2 days after (group 2), 2 days before to 2 days after (group 3) and 2 days before RAIT (group 4). Serum oxidative stress markers including malondialdehyde (MDA), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) were measured immediately before and 2 days after RAIT. A significant increase in MDA after RAIT was observed in all groups (p?<?0.05). The concentrations of MDA were significantly higher in the control group compared to the intervention groups (p?<?0.05). A significant decrease in the control group (p?<?0.05) and increase in group 4 (p?<?0.05) were observed in GSH level after RAIT (p?<?0.05). Mean variation of GSH was significant between control group with groups 3 (p?<?0.01) and 4 (p?<?0.01). The results indicate that activity of SOD remained unchanged in all groups (p?>?0.05). A significant increase was observed in CAT activity after RAIT in all groups (p?<?0.05), which was higher in control group than intervention groups. In groups 3 (p?<?0.05) and 4 (p?<?0.05), this increase in CAT activity was significantly lower than the control group. RAIT causes serum oxidative stress, which can be ameliorated using vitamin C as an antioxidant. These results indicate that radioprotective effect of vitamin C is preferable to its mitigative effect.     

Effectiveness of eight-week zinc supplementation on vitamin D3 status and leptin levels in a population of postmenopausal women: a double-blind randomized trial

BackgroundThe menopausal period is characterized by hormonal imbalance related to the alteration of parameters involved in lipid metabolism. In addition, menopause increases the risk of deficiencies of key vitamins and minerals such as vitamin D and zinc in such women. The present study investigates the influence of zinc supplementation on the status of vitamin D₃ and other lipid parameters in postmenopausal women.MethodsFifty-one healthy postmenopausal women aged 44–76 years from the province of Granada (Spain) were divided into two groups (placebo and zinc) of 25 and 26 women, respectively. The zinc group was supplemented with 50 mg/day of zinc for 8 weeks. Nutrient intake assessment was performed by means of a 24 -h reminder. Zinc was determined by flame atomic absorption spectrophotometry. Vitamin D was analyzed by liquid chromatography - tandem mass spectrometry. Leptin was determined by enzyme immunoassay.ResultsZinc supplementation improved the initial vitamin D₃ status of the postmenopausal population (p = 0.049). Plasma levels of 25−OH-D₃ increased significantly after Zn supplementation in women with lower age at menopause (p = 0.045). Both intake and plasma zinc levels were inversely correlated to serum leptin levels (p = 0.044 and p = 0.033, respectively), being significantly lower in lower age at menopause (p < 0.001).ConclusionZinc supplementation improved vitamin D₃ status and was associated to low leptin levels in the postmenopausal women of the study.     

Effect of Zinc Supplementation on Thyroid Hormone Metabolism of Adolescents with Down Syndrome

Studies have evidenced that zinc metabolism is altered in the presence of Down syndrome, and zinc seems to have a relationship with the metabolic alterations usually present in this syndrome. In this work, the effect of zinc supplementation on thyroid hormone metabolism was evaluated in adolescents with Down syndrome. A prospective study was carried out on 16 adolescents with Down syndrome (age: 10–19 years) who were randomized for treatment with 30 mg zinc daily for 4 weeks. Diet evaluation was accomplished y using a 3-day dietary record, and the analysis was performed by the NutWin program, version 1.5. Anthropometric measurements were performed for evaluation of body composition. The Zn-related nutritional status of the groups was evaluated by means of zinc concentration determinations in plasma and erythrocytes using the method of atomic absorption spectroscopy, and the thyroid hormone was obtained by radioimmunoassay. The diet of patients with Down syndrome, before and after the intervention presented reduced energy level and adequate zinc concentrations. Mean plasma zinc values were 59.2?±?13.2 and 71.0?±?21.9 μg/dL before and after the intervention, respectively. Erythrocyte concentrations of the mineral before supplementation, instead, were 51.5 μg/dL?±?11.1 μg Zn/gHb, and at the end of the experiment, they were 42.9?±?8/5 μg Zn/gHb, with a significant statistical difference (p?<?0.05). Serum concentrations of T₄ hormone before and after zinc supplementation were 1.26?±?0.20 and 1.54?±?0.63 pg/mL, respectively. Mean T₃ values before intervention were 2.47?±?037 pg/mL and, after supplementation, 2.25?±?0.67 pg/mL, without significant statistical difference (p?>?0.05). Intervention with zinc showed to be effective in the stabilization of the concentrations of this mineral in plasma and erythrocytes, but had no influence on the metabolism of thyroid hormones.     

Effect of zinc deficiency and supplementation on lipid peroxidation of renal tissue in ovariectomized rats

The aim of this study was to investigate how zinc deficiency and supplementation affects lipid peroxidation in the renal tissue in ovariectomized rats. Four study groups were formed with 10 Spraque-Dawley rats each. Two of the groups served as normal and ovariectomized controls; the other two were ovariectomized rats that were zinc deficient and zinc supplemented, respectively. The zinc-deficient ovariectomized rats showed greater renal and plasma lipid peroxidation, as indicated by higher malondialdehyde levels than all other groups (p<0.05). These values were higher in the ovariectomized controls than those of the normal controls and of the ovariectomized, zinc-supplemented groups (p<0.05), which, in, turn, showed no significant differences of their respective renal and plasma malondialdehyde values. The renal and erythrocyte glutathione levels in the zinc-supplemented rats were higher than those in all other groups (p<0.05). The zinc-deficient group had the lowest renal and erythrocyte glutathione levels (p<0.05). The renal tissue zinc levels in the ovariectomized rats were higher than those in the zinc-deficient animals, but lower than in the normal controls and zincsupplemented rats (p<0.05). The zinc-supplemented animals had the highest renal tissue zinc levels (p<0.05). The results of this study suggest that zinc deficiency increases renal tissue damage in ovariectomized rats and that zinc supplementation can be used to prevent this condition.     

Effects of High Dietary Fluorine on Erythrocytes and Erythrocyte Immune Adherence Function in Broiler Chickens

Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C_3b receptor rosette rate (E-C_3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn–soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p?<?0.05 or p?<?0.01), and EOF was higher (p?<?0.05 or p?<?0.01) in the high F groups II and III than that in the control group from 14 to 42 days of age. The E-C_3bRR was significantly decreased (p?<?0.01) in the three high F groups, whereas the E-ICRR was markedly increased (p?<?0.01) in the high F groups II and III from 14 to 42 days of age. It was concluded that dietary F in the range of 800 to 1, 200 mg/kg could significantly cause anemia and impair the integrity of erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.     

Serum Trace Element Levels in Tuberculous Pleurisy

In this study, copper, zinc, magnesium, manganese, selenium, and iron were measured by inductively coupled plasma atomic emission spectrophotometry in patients with tuberculous (TB) pleurisy (n?=?24) and in the control group (n?=?20). Selenium, magnesium, and zinc were found to be significantly lower in TB pleurisy cases than those in the control group (p?<?0.01, p?<?0.001, and p?<?0.001, respectively). There was no significant difference in the value of manganese and iron between TB pleurisy and the control group (p?>?0.05). Copper levels were significantly increased in the serum of the patients (p?<?0.0001). These results may provide an additional disease correlate for assessing TB pleurisy risk.     

Effects of zinc supplementation on the plasma glucose level and insulin activity in genetically obese (ob/ob) mice

The effects of zinc supplementation (20 mM ZnCl₂ from the drinking water for eight weeks) on plasma glucose and insulin levels, as well as its in vitro effect on lipogenesis and lipolysis in adipocytes were studied in genetically obese (ob/ob) mice and their lean controls (+/?). Zinc supplementation reduced the fasting plasma glucose levels in both obese and lean mice by 21 and 25%, respectively (p < 0.05). Fasting plasma insulin levels were significantly decreased by 42% in obese mice after zinc treatment. In obese mice, zinc supplementation also attenuated the glycemic response by 34% after the glucose load. The insulin-like effect of zinc on lipogenesis in adipocytes was significantly increased by 80% in lean mice. However, the increment of 74% on lipogenesis in obese mice was observed only when the zinc plus insulin treatment was given. This study reveals that zinc supplementation alleviated the hyperglycemia of ob/ob mice, which may be related to its effect on the enhancement of insulin activity.     

The Effect of Low Dose Zinc Supplementation to Serum Estrogen and Progesterone Levels in Post-menopausal Women

The objective of the present study is to investigate how low-dose zinc supplementation for 2 weeks in the post-menopausal period influences levels of estrogen and progesterone in the serum. The study registered 32 natural menopause patients, who were allocated to four groups with equal number of patients. Group 1, control group, which was not subjected to any procedure. Group 2, the group that was supplemented with 15 mg/day zinc sulfate for 2 weeks. Group 3, the group that was given hormone replacement therapy (0.625 mg estrogen?+?5 mg medroxyprogesterone acetate/day) for 2 weeks. Group 4, the group that received hormone replacement therapy (0.625 mg estrogen?+?5 mg medroxyprogesterone acetate/day) and zinc sulfate (15 mg/day) for 2 weeks. Blood samples were collected twice from each subject, once at the beginning of the study, and once at the end of the 4-week procedure to determine estrogen (E2) and progesterone levels. Variance analysis was employed in the statistical evaluation of data. Level of significance was set at p?<?0.05. No significant difference was found between the estrogen and progesterone levels of groups 1 and 2. Groups 3 and 4 had higher estrogen and progesterone levels than groups 1 and 2 (p?<?0.05). Estrogen and progesterone levels in groups 3 and 4 were not different. Results of the study show that low-dose zinc supplementation to post-menopausal women for 2 weeks does not have a significant effect on the concerned parameters.     

The Effects of FeCl<Subscript>3</Subscript> and Fe–EDTA on the Development of Psoriasis

The effects of FeCl₃ and Fe–EDTA on the development of psoriasis were studied in the mouse model of vaginal epithelium and tail epidermis. The mitoses of vaginal epithelial cell in female mice of their estrogenic stage and the formation of granular cell layers in male mouse tail scale were observed. Mice were randomly divided into eight groups and treated with normal saline, methotrexate, and different doses of two iron forms, FeCl₃ and Fe–EDTA, respectively, for 10 days. To explore the influence of FeCl₃ and Fe–EDTA on the excretion of Cu, Fe, Zn, Ca, Mg, Mn, and Se, the concentration of those elements in liver and kidney was analyzed by atomic absorption spectrometry. The different doses of FeCl₃ or Fe–EDTA could obviously inhibit the mitoses of vaginal epithelial cell (p< 0.05) and promote the formation of granular cell layers in mice tail scale (p < 0.05). No statistically significant results were found between the groups of FeCl₃ and Fe–EDTA, and between experimental groups and methotrexate group acted as the positive control (p>0.05). Compared with the negative group, the concentrations of Cu, Fe, Zn, Ca, Mg, Mn, and Se in liver and kidney of experimental groups and positive control group were not significantly changed (p > 0.05). FeCl₃ and Fe–EDTA are as effective as methotrexate on inhibiting hyperplasia of epidermal cells and increasing the formation of granular cell layers, and the concentrations of Cu, Fe, Zn, Ca, Mg, Mn, and Se in liver and kidney of experimental groups and positive control group were not significantly changed compared with the negative group, possibly retarding the development of psoriasis.     

Antioxidant properties of chromium and zinc

The effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO₄H₂O) supplementation on serum concentrations of malondialdehyde (MDA) (an indicator of lipid peroxidation) and serum status of some antioxidant vitamins and minerals of laying hens (Hy-Line) reared at a low ambient temperature (6.8°C) were evaluated. One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The hens were fed either a basal diet or the basal diet supplemented with either 0.4 mg Cr/kg of diet, 30 mg Zn/kg of diet, or 0.4 mg Cr plus 30 mg Zn/kg of diet. Digestibility of nutrients (dry matter [DM], organic matter [OM], crude protein [CP], and ether extract [EE]) increased by supplementation of chromium and zinc (p<0.05). Supplemental chromium and zinc increased serum vitamins C and E but decreased MDA concentrations (p<0.05). Additionally, supplemental chromium and zinc caused an increase in the serum concentrations of Fe, Zn, Mn, and Cr (p < 0.05). The present study showed that low ambient temperature causes detrimental effects on the digestibility of nutrients and antioxidant status and that such detrimental effects caused by low ambient temperature can be alleviated by chromium and zinc supplementation, particularly when Cr and Zn were simultaneously included into the diet. Data obtained in the present study suggest that such supplementation can be considered as a protective management practice in a diet of laying hens for alleviating negative effects of cold stress.     

Skeletal muscle post-conditioning by diazoxide, anti-oxidative and anti-apoptotic mechanisms

Pretreatment with diazoxide, K_ATP channel opener, increases tissue tolerance against ischemia reperfusion (IR) injury. In clinical settings pretreatment is rarely an option therefore we evaluated the effect of post-ischemic treatment with diazoxide on skeletal muscle IR injury. Rats were treated with either saline, diazoxide (K_ATP opener; 40?mg/kg) or 5-hydroxydecanoate (5-HD; mitochondrial K_ATP inhibitor; 40?mg/kg) after skeletal muscle ischemia (3?h) and reperfusion (6, 24 or 48?h). Tissue contents of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, Bax and Bcl-2 protein expression and muscle histology were determined. Apoptosis was examined (24 and 48?h) after ischemia. IR induced severe histological damage, increased MDA content and Bax expression (24 and 48?h; p?<?0.01) and decreased CAT and SOD activities (6 and 24?h, p?<?0.01 and 48?h, p?<?0.05), with no significant effect on Bcl-2 expression. Diazoxide reversed IR effects on MDA (6 and 24?h; p?<?0.05), SOD (6 and 24?h; p?<?0.01) and CAT (6 and 48?h, p?<?0.05 and 24?h p?<?0.01) and tissue damage. Diazoxide also decreased Bax (24 and 48?h; p?<?0.05) and increased Bcl-2 protein expression (24 and 48?h; p?<?0.01). Post-ischemic treatment with 5-HD had no significant effect on IR injury. Number of apoptotic nuclei in IR and 5-HD treated groups significantly increased (p?<?0.001) while diazoxide decreased apoptosis (p?<?0.01). The results suggested that post-ischemic treatment with diazoxide decrease oxidative stress in acute phase which modulates expression of apoptotic proteins in the late phase of reperfusion injury. Involvement of KATP channels in this effect require further evaluations.