Angiotensin-converting enzyme inhibitors reduce oxidative stress intensity in hyperglicemic conditions in rats independently from bradykinin receptor inhibitors.

AIM: To investigate whether endogenous bradykinin is involved in the antioxidant action of angiotensin-converting enzyme inhibitors (ACEIs) in acute hyperglycemia. METHODS: Male Wistar rats were divided into the normoglycemic group (n=40) and the hyperglycemic group (n=40). Hyperglycemia was induced by a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg body weight) dissolved in 0.1 mol/L citrate buffer (pH 4.5) 72 hours before sacrifice. The normoglycemic group received the same volume of citrate buffer. Each group was divided into five subgroups (n=8): control group, captopril group, captopril + bradykinin B1 and B2 receptor antagonists group, enalapril group, and enalapril + bradykinin B1 and B2 receptor antagonists group. Captopril, enalapril, B1 and B2 receptor antagonists, or 0.15 mol/L NaCl were given at 2 and 1 hour before sacrifice. Oxidative status was determined by measuring the concentration of malondialdehyde and H2O2, and the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). RESULTS: In STZ-induced hyperglycemic rats ACEIs significantly reduced H2O2 concentration, while they significantly enhanced SOD and GPx activity. The hyperglycemic group treated simultaneously with ACEIs and bradykinin B1 and B2 receptor antagonists showed a significant decrease in H2O2 concentration compared to the control hyperglycemic group. CONCLUSION: These results suggest the existence of the bradykinin -independent antioxidative effect of ACEIs in hyperglycemic conditions, which is not related to the bradykinin mediation and the structure of the drug molecule.

Selected oxidative stress markers in gynecological laparoscopy.

INTRODUCTION: The surgical stress response after laparoscopy is smaller when compared with open surgery, and it is expected that after minimally invasive surgery the possible development of oxidative stress will be less severe. AIM: To evaluate markers of pro-oxidant activity - levels of lipid peroxides and malondialdehyde - and activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in the perioperative period in patients undergoing gynecological laparoscopy and to determine whether the duration of laparoscopy can affect these changes. MATERIAL AND METHODS: The study included 64 patients, divided into two groups: group 1 with duration of laparoscopy up to 20 min, and group 2 with duration of the operation over 40 min. Blood samples were collected before anesthesia, 5 min after release of pneumoperitoneum, and 10 h after surgery. RESULTS: A statistically significant increase in the levels of lipid peroxides and malondialdehyde in samples collected after surgery was found in comparison with values obtained before surgery. Also statistically significant differences existed between groups of patients with different duration of surgery. Superoxide dismutase and glutathione peroxidase activity values were significantly decreased. They were also significantly different between the two groups with different duration of surgery. CONCLUSIONS: In our study, levels of the markers of pro-oxidant activity increased and levels of the markers of antioxidant enzymes decreased, suggesting development of oxidative stress. The duration of laparoscopic procedures affects the severity of the presented changes.

Allergy to selected cosmetic ingredients.

In an era in which cosmetics are commonly used, their often prolonged contact with the human body should determine the safety of their use. Often cosmetics are the cause of many side effects, mainly hypersensitivity reactions. Common groups of cosmetic components responsible for side effects are fragrances, preservatives and dyes. This paper focuses on the most allergenic components.

[Estimation of oxidative stress and its correlation with uterine arteries Doppler velocimetry in women with preeclampsia]. / Ocena stresu oksydacyjnego i jego korelacji z przeplywami krwi w tetnicach macicznych u kobiet ze stanem przedrzucawkowym.

OBJECTIVES: Estimation of oxidative stress through the measurement of lipid peroxides and malondialdehyde serum concentration as well as serum antioxidants level expressed by total antioxidants status and its correlation with Doppler velocimetry in women with preeclampsia. MATERIAL AND METHODS: Thirty four patients with preeclampsia at third trimester of gestation: 19 with the mild form and 15 with the severe form of the disease, 21 women with uncomplicated pregnancy at third trimester of gestation served as a control group. Colorimetric methods were used to estimate lipid peroxides, malondialdehyde and antioxidants serum level. In each patient Pulsatility Index and Uterine Artery Score in uterine arteries was measured. RESULTS: Serum concentration of lipid peroxides and malondialdehyde was the highest in patients with severe preeclampsia, but the statistical difference concerned only lipid peroxides level which was significantly higher in this group than in women with mild form of the disease and in the control group. Pulsatility index Uterine Artery Score values were significantly higher in women with severe preeclampsia in comparison to two other groups of patients. Lipid peroxides level significantly positively correlated with Pulsatility Index and Uterine Artery Score values in the whole studied population. CONCLUSIONS: Only severe form of preeclampsia is associated with oxidative stress which impaired placenta perfusion expressed by the increase of uterine arteries resistance.

The influence of glimepiride on the binding kinetics of insulin with its skeletal muscle and liver receptors in rats with short term and prolonged hyperglycemia induced by streptozotocin.

BACKGROUND: The aim of the study was to determine the influence of glimepiride on the binding kinetics of insulin with its skeletal muscle receptor in rats with transient and prolonged hyperglycemia induced by streptozotocin. MATERIAL/METHODS: The studies were performed on healthy male Wistar rats with a body mass of 220+/-30 g, fed with LSM-type standard chow, and given water ad libitum. Transient or prolonged hyperglycemia was induced by intraperitoneal administration of streptozotocin. Blood samples were taken from the right heart ventricle to heparinized test tubes and centrifuged for 10 minutes at 700 i. g. Plasma was collected and the glucose level was determined. From each animal 1 g of skeletal muscle and 1 g of liver were collected as well, placed in liquid nitrogen and stored until determination of the affinity and number of receptors. RESULTS: We found an increase in affinity and binding capacity of high- and low-affinity receptors in rats with both transient and prolonged streptozotocin-induced hyperglycemia. The affinity and binding capacity of receptors increased under the influence of glimepiride in transient hyperglycemia caused by streptozotocin administration. CONCLUSIONS: The affinity and binding capacity of receptors increased under the influence of glimepiride in the course of transient hyperglycemia. The lack of changes in the specific insulin binding and binding capacity of receptors of both low and high affinity in the group of animals with prolonged hyperglycemia requires explanation.

The influence of glimepiride on the oxidative state of rats with streptozotocin-induced hyperglycemia.

BACKGROUND: The aim of this work was to determine whether glimepiride, a derivate of sulphonylurea of the hypoglycemic effect, influences the level of prooxidative factors and antioxidative enzymes activity in the course of experimental streptozotocin hyperglycemia in rats. MATERIAL/METHODS: The studies were performed on healthy male Wistar rats of body weight 200+/-30 g, fed with the standard laboratory diet and given water ad libitum. Animals were divided into 3 groups, each consisting of 8 rats. Group I--control animals, Group II--animals in which experimental hyperglycemia was induced by intraperitoneal administration of streptozotocin (65 mg/kg body mass), Group III--animals which were given glimepiride orally for seven weeks (200 mg/kg of body mass), starting 24 hours after streptozotocin administration. Using Ohkawa method, malondialdehyde level was determined in plasma for all groups. Concentration of hydrogen peroxide was determined using method developed by Frew and co-workers, superoxide dismutase activity using the Misra and Fridovich method and activity of glutathione peroxidase by means of Ransel kit [Randox, Great Britain]. The decrease of glucose level in serum of rats under the influence of streptozotocin and glimepiride was observed when compared with the group given placebo. RESULTS: Glimepiride administration caused a decrease of peroxides and malondialdehyde levels and increase in activity of superoxide dismutase and glutathione peroxidase in rats, after streptozotocin had been administered. CONCLUSIONS: The results suggest that glimepiride may effectively inhibit the development of the oxidative stress in diabetes.

Oxidative stress may be a piece in the endometriosis puzzle.

OBJECTIVE: To assess the total antioxidant potential of women with endometriosis-associated infertility, women with idiopathic infertility, and fertile controls. DESIGN: Retrospective study. SETTING: University medical hospital. PATIENT(S): Sixty-five women admitted for diagnostic laparoscopy. MAIN OUTCOME MEASURES: Peritoneal fluid samples were analyzed for superoxide dismutase activity and total antioxidant status on spectrophotometry, glutathione peroxidase activity on enzyme-linked immunosorbent assay, and lipid peroxides levels on colorimetry. RESULT(S): Mean activity of superoxide dismutase, glutathione peroxidase, and total antioxidant status was lowest and lipid peroxide level was highest among infertile patients with endometriosis. Women with idiopathic infertility, in contrast, had the highest superoxide dismutase, glutathione peroxidase, and total antioxidant status activity and the lowest lipid peroxide level. CONCLUSION(S): High antioxidant potential is not a contributing factor in women with idiopathic infertility. Low total antioxidant status and low activity of antioxidant enzymes in the peritoneal fluid of infertile women with endometriosis probably do not influence fertility in these women, but these factors may play a role in the development of the disease.