Augmentation of indices of oxidative damage in life-long melatonin-deficient rats

The chief pineal secretory product, melatonin, is an efficient free radical scavenger and antioxidant. The current study tested whether the life-long reduction of endogenous melatonin levels due to pinealectomy would influence the accumulation of oxidatively damaged products as the animals aged. Rats were either pinealectomized or sham operated when they were 2-months-old. At 25 months of age these animals were killed along with 2-month-old controls. Aging in the pineal-intact animals was associated with increased levels of lipid peroxidation products (malondialdehyde and 4-hydroxyalkenals in the lung, kidney and skin), rises in an oxidatively damaged DNA product (8-hydroxy-deoxyguanosine in liver, kidney and pancreas), and in the levels of protein carbonyls (in the liver). Likewise, advanced age was associated with a significant decrease in membrane fluidity (increased membrane rigidity) of hepatic microsomes in pineal-intact rats. For all of these parameters and in a number of organs, pinealectomy caused further increases in the indices of oxidative damage. Consistent with previous suggestions, the implications of these findings is that aging is associated with the augmented accumulation of oxidatively damaged macromolecules and that these increases are exaggerated when a relative melatonin deficiency is induced by pinealectomy. The findings are consistent with the idea that the accelerated accumulation of oxidatively damaged products after pinealectomy was due to reduction in melatonin since it functions as a free radical scavenger and antioxidant. On the other hand, other pineal secretory products that were reduced as a consequence of pineal removal may have also been responsible for some of the observed changes.     

Sperm protein carbonylation

The cryopreservation of sperm is a well established technique that plays an essential role in dissemination of elite germplasm of livestock. Despite having numerous advantages, the cryopreservation induces certain stresses on sperm including structural and functional damages leading to impaired sperm quality and fertility, which might be associated with production of reactive oxygen species (ROS). In addition, the ROS upon reacting with sperm lipids, DNA and proteins may lead to a cascade of sperm damages. The sperm membrane contains a rich amount of polyunsaturated fatty acids, which increases their susceptibility to oxidative stress induced damages, leading to formation of secondary products. These secondary products result in oxidation of sperm proteins via carbonylation. The carbonylation could lead to disturbances in specific proteins that are involved in capacitation. The present review deals with sperm protein carbonylation.     

Oxidative stress, evident in antioxidant defences and damage products, in rainbow trout caged outside a sewage treatment plant

Sewage treatment plants (STPs) are common sources of a wide variety of chemicals entering into the aquatic environment. We have investigated the effects of STP effluent on oxidative stress parameters in rainbow trout via measurements of several enzymatic antioxidants as well as the molecular antioxidant glutathione (GSH). In addition, we have measured levels of oxidative damage, i.e. protein carbonyls and lipid peroxides. Our findings indicate that STP effluent does contain prooxidants that affect fish. Oxidative damage was a more consistent indicator of exposure to prooxidants than antioxidant enzymes. Protein carbonyls and lipid peroxides were both elevated (1.3- and 1.8-fold increases, respectively) in fish caged at the STP site compared with reference site as was the amount of oxidized GSH (GSSG), which showed a 3-fold increase. Antioxidant enzymes showed no clear-cut response. Additionally, older pollutants that have been present in down stream sediment for decades had no effects on the parameters measured here.     

P&T-GC法测定环境大气中的醛酮和苯

目的:醛、酮类污染物是环境中的主要污染物之一,其来源广、毒性大,各国对其排放都进行了严格的限制。准确检测环境中的醛、酮类污染物是评价环境质量的基础。为此建立了PT-GC法测定环境大气中的乙醛、丙醛、丁醛、丙酮、2-丁酮和苯。方法:通过水对环境大气进行捕集,利用吹扫捕集-气相色谱检测分析。结果:此方法有较好的重复性,相对标准偏差在4.8%以下;检出限为0.85~6.55 ng;6种物质的回收率在96.7%~101.3%之间。结论:该方法不用有机溶剂萃取和浓缩,减少了对环境的污染,具有灵敏度高、检出限低、定量准确、操作简便等特点。     

Neuropeptide S produces hyperlocomotion and prevents oxidative stress damage in the mouse brain: A comparative study with amphetamine and diazepam

Neuropeptide S (NPS) is a recently discovered peptide which induces hyperlocomotion, anxiolysis and wakefulness. This study aimed to compare behavioral and biochemical effects of NPS with amphetamine (AMPH), and diazepam (DZP). To this aim, the effects of NPS (0.01, 0.1 and 1 nmol, ICV), AMPH (2 mg/kg, IP) and DZP (1 mg/kg, IP) on locomotion and oxidative stress parameters were assessed in mouse brain structures. The administration of NPS and AMPH, but not DZP, increased locomotion compared to control. Biochemical analyses revealed that AMPH increased carbonylated proteins in striatum, but did not alter lipid peroxidation. DZP increased lipid peroxidation in the cortex and cerebellum, and increased protein carbonyl formation in the striatum. In contrast, NPS reduced carbonylated protein in the cerebellum and striatum, and also lipid peroxidation in the cortex. Additionally, the treatment with AMPH increased superoxide dismutase (SOD) activity in the striatum, while it did not affect catalase (CAT) activity. DZP did not alter SOD and CAT activity. NPS inhibited the increase of SOD activity in the cortex and cerebellum, but little influenced CAT activity. Altogether, this is the first evidence of a putative role of NPS in oxidative stress and brain injury.     

Protein carbonyls as a biomarker of foetal-neonatal hypoxic stress

Objectives:

Investigation of the effect of hypoxic conditions during labour on the protein oxidative modifications and changes in plasma antioxidative capacity of newborns.

Design and methods:

Oxidative damage to proteins was determined by high-performance liquid chromatography. Antioxidative status was monitored by Trolox equivalent antioxidant capacity method. In our study, 11 hypoxic and 19 normoxic newborns were involved.

Results:

In hypoxic newborns, we have found a significant increase in protein carbonyl levels (3.55 ± 0.86 versus 3.24 ± 0.69 mol carbonyls/mol proteins, p = 0.045) and plasma antioxidant capacity (1.76 ± 0.056 versus 1.68 ± 0.097 mmol Trolox/L, p = 0.004) when compared to normoxic children. Bilirubin levels were unchanged (p = 0.87).

Conclusion:

Our results show elevated levels of carbonyls in hypoxic neonates compared to normoxic children. The oxidative damage to proteins is not sufficiently prevented by increased antioxidant capacity detected in plasma of hypoxic newborns.     

Blood flow regulation and oxidative stress during submaximal cycling exercise in patients with cystic fibrosis

Background

The impact of blood flow regulation and oxidative stress during exercise in cystic fibrosis (CF) has yet to be investigated.

Oxidative stress and dopamine depletion in an intrastriatal 6-hydroxydopamine model of Parkinson's disease

Although the etiology of Parkinson's disease (PD) is unknown, a common element of most theories is the involvement of oxidative stress, either as a cause or effect of the disease. There have been relatively few studies that have characterized oxidative stress in animal models of PD. In the present study a 6-hydroxydopamine (6-OHDA) rodent model of PD was used to investigate the in vivo production of oxidative stress after administration of the neurotoxin. 6-OHDA was injected into the striatum of young adult rats and the production of protein carbonyls and 4-hydroxynonenal (HNE) was measured at 1, 3, 7, and 14 days after administration. A significant increase in both markers was found in the striatum 1 day after neurotoxin administration, and this increase declined to basal levels by day 7. There was no significant increase found in the substantia nigra at any of the time points investigated. This same lesion paradigm produced dopamine depletions of 90-95% in the striatum and 63-80% in the substantia nigra by 14-28 days post-6-OHDA. Protein carbonyl and HNE levels were also measured in middle-aged and aged animals 1 day after striatal 6-OHDA. Both protein carbonyl and HNE levels were increased in the striatum of middle-aged and aged animals treated with 6-OHDA, but the increases were not as great as those observed in the young adult animals. Similar to the young animals, there were no increases in either marker in the substantia nigra of the middle-aged and aged animals. There was a trend for an age-dependent increase in basal amounts of oxidative stress markers when comparing the non-lesioned side of the brains of the three age groups. These results support that an early event in the course of dopamine depletion following intrastriatal 6-OHDA administration is the generation of oxidative stress.