Some Antioxidants and Malondialdehyde Levels in the Flesh of Rainbow Trout, (Oncorhynchus mykiss W., 1792) from Various Feeding Habitats.

The present study was aimed to find the effect of feeding habitats on the amounts of some antioxidants (vitamin A, E, C, ß-carotene and selenium) and malondialdehyde (MDA) levels in the flesh of rainbow trout (Oncorhynchus mykiss). For this purpose, vitamins (A, C and E), ß-carotene amounts and malondialdehyde (MDA) levels were determined by HPLC and selenium amount was determined by fluorometric method in the flesh of rainbow trout obtained from various feeding habitats. The highest amounts of vitamins (A, C and E), ß-carotene and selenium were found in the flesh of wild rainbow trout (WRT), followed by cage reared rainbow trout (CRRT) and pond reared rainbow trout (PRRT). However, the levels of MDA in the flesh of PRRT were the highest, followed by CRRT and the lowest in WRT.

Ghrelin and orotic acid increased in subclinical mastitis.

Hormone ghrelin and orotic acid accelerate wound healing as well as controlling inflammation and immunity. We have, therefore, investigated the serum and milk levels of ghrelin and orotic acid in dairy cows with (n = 21) or without (n = 21) subclinical mastitis. Acylated and des-acylated ghrelin as well as orotic acid concentration were detected by using high performance liquid chromatography (HPLC). The results revealed that ghrelin level in milk and serum was significantly higher in dairy cows with subclinical mastitis than that of dairy cows without subclinical mastitis. This was also the case when the orotic acid concentrations in dairy cows with subclinical mastitis were compared with those dairy cows without subclinical mastitis. In conclusion, ghrelin and orotic acid occur in particularly high concentrations in subclinical mastitis, and might, therefore, be required in greater amounts for tissue repair and may be also used as a indicator for subclinical mastitis.

Effects of supportive treatment such as antioxidant or leukotriene receptor antagonist drugs on inflammatory and respiratory parameters in asthma patients.

In this study, prospectively, we aimed to determine the effects of the different treatment alternatives on the oxidant system and inflammatory and clinic determinants during the stable period of 1 month following an asthmatic attack. Thirty-one patients (22 female, nine male) were randomly divided into three groups following the stabilization of an acute asthma attack. The control group that is an additional group to the three patient groups consisted of 10 healthy volunteers (five female, five male). The following protocols were used for 4 weeks: Group I: short-acting inhaler beta2 mimetic as required (treatment A)+800 mug inhaler budesonide (treatment B)+leukotriene receptor antagonist; Group II: treatment A and B; Group III: treatment A and B+vitamin E. The serum levels before and after treatment of eosinophilic cationic protein (ECP), leukotriene E4 (LTE(4)), and malondialdehyde (MDA) were determined. The values before and after treatment were statistically compared both with each other and control values. Pretreatment ECP, LTE(4), and MDA levels for the three groups were significantly higher compared with post-treatment levels (P<0.05 to P<0.001) and the control levels (P<0.01 to P<0.001). However, when post-treatment levels were compared with those of the control group, no significant differences were found (P>0.05). Lack of significant variation was observed when the pre- and post-treatment differences in the three groups were compared for each one of ECP, LTE(4), and MDA levels (P>0.05). Leukotriene receptor antagonist or antioxidant agents added to standard asthma treatment did not make a significant contribution on ECP, LTE(4), and MDA levels and respiratory parameters such as spirometric function tests. Etiologic factors and/or the possible changes in different pathogenetic ways of the inflammation process may have been responsible for nonsignificant intertreatment difference in the biomarker levels. The result confirms that suppressing the inflammation in asthma enables the entire inflammatory pathologic process to be controlled.

[Synthesis of two new acetanilide derivatives and their effect on the serum antioxidant vitamins (A, E, and C) and the MDA level in rats].

Acetanilide derivatives, 2,2'-thiobis[N-(4-nitrophenyl)acetamide] and 2,2'-thiobis[N-(4-chlorophenyl)acetamide], were synthesized and characterized. They were shown to cause a considerable oxidative stress in rats.

Investigation of antioxidant vitamins (A, E, C) and lipid peroxidation levels in rats injected N-(1,3-benzothiazol-2-yl)-N-(4,5-dihydro-1H-imidazol-2-yl) amine.

The present study examined the influence of synthetic N-(1,3-benzothiazol-2-yl)-N-(4,5-dihydro-1H-imidazol-2-yl) amine (2-Amdz) on levels of vitamins A, E and C and malondialdehyde (MDA) in rats. A total of 30 rats, divided into two groups, were used in the study. The control group was given only a subcutaneous injection of 250 microL 75% ethanol, every other day. The other group of rats was administered a subcutaneous injection of 2-Amdz (25 mg kg-1, dissolved in 250 microL of 75% ethanol). Injections were continued for 16 days. After the application of 2-Amdz for 16 days, the serum levels of vitamins A, E and C and malondialdehyde (MDA) were determined by HPLC. The serum vitamin A, E, and C levels decreased significantly compared to controls (p<0.05) whereas serum MDA levels were higher than control levels (p<0.005). As a result, it can be suggested that 2-Amdz induced a severe stress and more importantly, increased the amount of free radicals and significantly decreased the levels of serum antioxidant vitamins.

Oxidant and antioxidant levels in preterm newborns with idiopathic hyperbilirubinaemia.

OBJECTIVES: Newborns, particularly preterm infants, have limited antioxidant protective capacity. The organism's defence system against reactive oxygen species including vitamins A, E and C, trace element selenium (Se) and enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) are essential components of the antioxidant system against the oxidative injury to the cellular membranes of erythrocytes. In this study, our aim was to compare the oxidant nitric oxide (total plasma nitrite level as an indicator of nitric oxide (NO)), antioxidant vitamins and selenium and erythrocyte antioxidant enzymes in premature babies with hyperbilirubinaemia with healthy preterms. METHODS: Twenty preterm infants with newborn jaundice were included in the study group, while 15 preterm infants without jaundice were enrolled in the control group. We evaluated the mean plasma levels of, respectively, the total nitrite as an indicator of NO, bilirubin, vitamins A, E, C and selenium, and the activity of erythrocyte antioxidant enzymes such as CAT, SOD and GSH-Px of preterm infants with idiopathic hyperbilirubinaemia and compared to those of the control group. RESULTS: The mean plasma total nitrite and total serum bilirubin levels and blood reticulocyte counts of the study group were found to be significantly higher than those of the control group (P < 0.001, P < 0.001 and P < 0.05, respectively). Furthermore, the activity of erythrocyte antioxidant enzymes (all P < 0.001) and the mean plasma levels of the antioxidant vitamins A, E, and C (P < 0.05, P < 0.05 and P < 0.001, respectively) and selenium (P < 0.001) of the study group were all found to be significantly lower than those of the control group. CONCLUSION: We hypothesize that low antioxidants in pretem babies may predispose them to increased oxidative stress, and cause hyperbilirubinaemia.

The levels of glutathione peroxidase, vitamin A, E, C and lipid peroxidation in patients with transitional cell carcinoma of the bladder.

OBJECTIVE: To assess the levels of erythrocyte glutathione peroxidase (GSH-Px), and the serum levels of antioxidant vitamins (A, E and C), selenium and malondialdehyde (MDA) in patients with transitional cell carcinoma (TCC) of the bladder. PATIENTS, SUBJECTS AND METHODS: The study comprised 91 people (23 healthy controls and 68 patients with TCC). Erythrocyte GSH-Px activity was measured by spectrophotometry, high-performance liquid chromatography to detect serum levels of vitamins and MDA, and fluorometry to detect serum levels of selenium. RESULTS: The serum levels of vitamin A, E and C, and selenium were significantly lower (P < 0.05) in patients with TCC than in controls. However, erythrocyte GSH-Px activities (P < 0.05) and serum MDA levels (P < 0.01) were significantly higher in patients with TCC than in the controls. CONCLUSIONS: Levels of free oxygen species were higher, and antioxidant vitamin and selenium levels lower, in patients with bladder TCC than in controls. These findings, with the results of previous animal studies, suggest that giving vitamin A, C, E and selenium may be beneficial in preventing and treating human bladder cancer.

Antioxidant status & lipid peroxidation in patients with rheumatoid arthritis.

BACKGROUND & OBJECTIVES: Rheumatoid arthritis (RA) is a debilitating, chronic multisystem disease with an unknown etiology. Recent findings indicate that increased oxidative stress and/or defective antioxidant status contribute to the etiology of RA. The present study was undertaken to examine the oxidant and antioxidant systems in patients with RA and healthy controls. METHODS: Twenty two patients with RA and 20 healthy volunteers were included in the study. Levels of malondialdehyde (MDA) and antioxidant vitamins (A, E, C) in serum samples were determined by high performance liquid chromatography (HPLC). Spectrophotometric methods were used to determine activity levels of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), in erythrocytes. RESULTS: MDA levels in patients with RA were found to be significantly (P<0.005) higher than controls whereas levels of vitamins A, E, C and activities of GSH-Px, SOD were lower in the patients compared to controls (P<0.005 for SOD and antioxidant vitamins; P<0.05 for GSH-Px). INTERPRETATION & CONCLUSION: There was an increased oxidative stress and a low antioxidant status in patients with RA. These changes are probably due to efforts for reducing lipid peroxidation and hence to lower tissue damage.

Determination of free malondialdehyde in human serum by high-performance liquid chromatography.

Lipid peroxidation involves the oxidative deterioration of polyunsaturated fatty acids in biomembranes and generates a variety of aldehydic products including malondialdehyde (MDA). To demonstrate the occurrence of lipid peroxidation in biological systems, the production of MDA has been shown to be a relevant indicator. Therefore, we describe a new method for measurement of free malondialdehyde in human serum. A simple, rapid but sensitive method for determination of MDA in human serum was applied to goiter patients and control groups. Patients with goiter had high levels of MDA compared to control groups. Our method is fast and practical for clinical measurements. The detection limit was found to be 1.2 x 10(-8) mol L(-1).

An investigation of orotic acid levels in the breastmilk of smoking and non-smoking mothers.

AIM: In this study; orotic acid levels in the milk of smoking and non-smoking mothers were investigated by high-performance liquid chromatography (HPLC). RESULTS: It was found that the amount of orotic acid in the milk of smoking mothers (3.92+/-0.20 micro g/ml) was higher than that of non-smoking mothers (1.66+/-0.15 micro g/ml). Orotic acids levels in the milk of smoking mothers in comparison with non-smokers were found to be statistically significant (P<0.005). CONCLUSION: Smoking may have increased the orotic acid levels by affecting pyrimidine biosynthesis pathway.

Changes in plasma angiotensin-converting enzyme activity and noradrenaline responses to long-term nitric oxide inhibition vary depending on their basal values in chickens.

In this study, we investigated the effects of N(omega)-nitro-L-arginine (L-NNA) on arterial blood pressure (BP), plasma noradrenaline (NA) and adrenaline (A) levels and angiotensin-converting enzyme (ACE) activity. L-NNA was applied with tap water (1 mg/ml) from the 3rd to the 8th week of age (group L-NNA1). In Experiment 1, long-term L-NNA application increased BP compared to the control group (group C1) (L-NNA1 = 131.4 +/- 6.3, n = 6; C1 = 82.7 +/- 4.7 mm Hg, n = 7) but decreased plasma noradrenaline and adrenaline levels and ACE activity (NA levels: C1 = 15.5 +/- 0.8, n = 7; L-NNA1 = 8.6 +/- 0.5 ng/ml, n = 7; A levels: C1 = 15.5 +/- 0.8, n = 7; L-NNA1 = 6.0 +/- 0.5 ng/ml, n = 7; ACE activities: C1 = 87.3 +/- 3.1, n = 6; L-NNA1 = 46.2 +/- 1.9 U/l, n = 5). On the other hand, in Experiment 2 (carried out under the same conditions and in age-matched chickens), blood pressure, plasma noradrenaline levels and ACE activity were found to differ in the control group (C2) (BP = 141.4 +/- 15.5 mm Hg, n = 7; NA = 1.1 +/- 0.4 ng/ml, n = 7; ACE = 57.2 +/- 5.3 U/l, n = 7) as compared to C1, while plasma adrenaline levels were similar. In this series, long-term L-NNA application (group L-NNA2) did not change the BP, but surprisingly increased noradrenaline and ACE values (values of L-NNA2: BP = 165.7 +/- 15.6 mm Hg, n = 7; NA = 9.3 +/- 1.3 ng/ml, n = 8; ACE = 149.4 +/- 16 U/l, n = 8) while decreasing plasma adrenaline levels. L-arginine addition to L-NNA treatment completely reversed plasma noradrenaline and ACE activity values. These results indicate the modulatory activity of an L-arginine-NO pathway on adrenaline release as well as on the renin-angiotensin system in chickens.

Long-term lisinopril dihydrate application decreases plasma noradrenaline but not adrenaline levels in chickens.

Little is known about the effect of chronic angiotensin-converting enzyme inhibition on the catecholamine levels in fowls. In this study, we investigated the effects of chronic lisinopril dihydrate (Ld) application on the plasma levels of adrenaline and noradrenaline and on the blood pressure. Lisinopril was given in different concentrations (25, 75 and 250 mg/l drinking water) to the white Leghorn chickens for 9 weeks, while the control group drank tap water only. Twenty-eight hours after the last lisinopril application, arterial blood pressure (BP), plasma adrenaline and noradrenaline levels, plasma renin (PRA) and plasma angiotensin-converting enzyme (ACE) activities were determined. In all concentrations, lisinopril significantly increased PRA and decreased ACE activities. Arterial BP was decreased only in the group receiving high lisinopril concentration (Controls 119+/-10.27, Ld3 98+/-5.4 mm Hg). However, the lower lisinopril concentrations did not alter arterial BP compared to the control group. Plasma noradrenaline levels were decreased in a concentration-dependent manner (47-58%), but plasma adrenaline levels remained unchanged. The heart weight/body weight ratio was not changed in any of the lisinopril-treated groups. The persistent decrease in the blood pressure after lisinopril treatment was not directly related to a decrease of plasma ACE activity or plasma noradrenaline levels. Its mechanism still remains to be elucidated.

Low levels of selenium in mothers and their newborns in pregnancies with a neural tube defect.

OBJECTIVE: Very few data are presented in the literature about selenium (Se) in human fetal development. The aim of this paper was to study the relationship between maternal and neonatal Se status and neural tube defects (NTDs). PATIENTS AND METHODS: Serum and hair samples were obtained from 20 nonpregnant women, 32 healthy mothers with normal newborns, and 28 mothers who had a newborn with NTD, and their newborns at delivery. Serum Se levels, as ng/mL, and hair Se levels, as microgram/g, were determined on a Perkin-Elmer 1000 spectrophotometer (United Kingdom) by fluorometry. RESULTS: The mean maternal serum and hair Se concentrations in the NTD group (42.9 +/- 1.75 ng/mL, 277 +/- 7.73 ng/g, respectively) were significantly lower than those of the control healthy mothers (50.2 +/- 2.35 ng/mL, 300 +/- 6.10 ng/g, respectively) and the nonpregnant women (58.1 +/- 3.12 ng/mL, 315 +/- 7.64 ng/g, respectively). A significant decrease in concentrations of Se in serum and hair was observed in newborns with a NTD (26.0 +/- 1.55 ng/mL, 181 +/- 3.71 ng/g, respectively) compared with healthy newborns (32.6 +/- 1.70 ng/mL, 204 +/- 4.43 ng/g, respectively). CONCLUSIONS: Maternal Se deficiency during pregnancy was thought to be one of the factors responsible for NTDs. However, the lowered serum and hair Se concentrations may be secondary manifestations of an abnormal pregnancy and did not contribute to its production. More studies on maternal Se status during the antenatal period, especially early gestation and neonatal Se status including normal newborns and NTD infants, are needed.