Effect of agmatine on acute and mononeuropathic pain

Agmatine is a polycationic amine synthesized from L-arginine by arginine decarboxylase in brain and several tissues. It binds to N-methyl-D-aspartate (NMDA) subtype of glutamatergic, alpha(2)-adrenergic and imidazoline (I) receptors. The present study was designed to investigate effect of agmatine on acute and mononeuropathic pain after chronic constriction injury (CCI). CCI was created by four loose ligations around the right sciatic nerve. The analgesic threshold in rats was evaluated by using thermal hyperalgesia/allodynia (THA) at 4 degreesC. The evaluations were made preoperatively, on postoperative day 15, and after drug administration. Agmatine (10, 20, 40, 80, and 100 mg/kg) was administered intraperitoneally for 5 days beginning on postoperative day 15. Agmatine significantly reduced the hyperalgesia in all doses applied. When agmatine was injected intraperitoneally (10, 20,40,80, and 100 mg/kg), it increased the nociceptive threshold in the tail-immersion test in a dose-dependent manner, but it had no effect in the hot-plate test. This effect of agmatine in the tail-immersion test was blocked by both yohimbine (1 mg/kg) and idazoxan (0.5 mg/kg). When agmatine was administered intracerebroventricularly (25-200 mug/10 muL), it increased the nociceptive threshold in the hot-plate but not in the tail-immersion test. We conclude that agmatine, an endogenous substance derived from arginine, can modulate both acute and chronic pain

Radiation-Induced Oxidative Damage on Collagen Molecule and Protective Effects of N-Acetylcysteine in Guinea Pigs Liver

WOS: 000282930700025The main biological effects of radiation are mediated by short-lived and very reactive chemical molecules called free radicals. Free radicals can oxidatively damage biological macromolecules such as DNA, lipids and proteins. Antioxidants are enzymes or other organic substances, which prevent or reduce damage caused by free radicals. N-acetyl-L-cysteine (NAC), a thiol compound, shows its effects as an antioxidant by scavenging free radicals directly or by being the precurser of glutathione, which is an important protective agent against free radicals in vivo. The aim of this study was to investigate the potential radioprotective properties of NAC against irradiation-induced oxidative damages in the liver tissues of guinea pigs after total body irradiation with a single dose of 485 cGy. After 24 h following radiation exposure, an increase was observed in the levels both of liver thiobarbuturic acid reactive substance (TBARS), which is an indicator of lipid peroxidation, and hydroxyproline (HYP), which is a major component of collagen and an indicator of tissue fibrosis. Concurrently, administration of NAC (200 mg/kg IP) in the irradiated group for 5 consecutive days before radiation exposure apparently diminished activities of lipid peroxidation and ameliorated accumulation of hydroxyproline in liver. In conclusion, the data obtained from this study indicate that application of NAC increased the functions of endogeneous antioxidant defense mechanisms in guinea pigs, and hence protected the organisms from radiation-induced liver damages.Gazi University research foundationGazi UniversityThis work was supported by grants from the Gazi University research foundation

Effect of harmane, an endogenous β-carboline, on learning and memory in rats

Our aim was to investigate the effects of acute harmane administration upon learning and memory performance of rats using the three-panel runway paradigm and passive avoidance test. Male rats received harmane (2.5, 5, and 7.5 mg/kg, i.p.) or saline 30 min. before each session of experiments. In the three panel runway paradigm, harmane did not affect the number of errors and latency in reference memory. The effect of harmane on the errors of working memory was significantly higher following the doses of 5 mg/kg and 7.5 mg/kg. The latency was changed significantly at only 7.5 mg/kg in comparison to control group. Animals were given pre-training injection of harmane in the passive avoidance test in order to determine the learning function. Harmane treatment decreased the retention latency significantly and dose dependently, which indicates an impairment in learning. In this study, harmane impaired working memory in three panel runway test and learning in passive avoidance test. As an endogenous bioactive molecule, harmane might have a critical role in the modulation of learning and memory functions. (c) 2012 Elsevier Inc. All rights reserved.Research Foundation of the Kocaeli UniversityKocaeli University [200439]The present study was supported by Research Foundation of the Kocaeli University (project number: 200439) and presented at EPHAR 2008 Congress, Manchester, UK, 13-17 July 2008

SERUM HOMOCYSTEINE, FOLATE, VITAMIN B12 LEVELS AND OXIDATIVE LIPID AND PROTEIN DAMAGE MARKERS IN DEPRESSIVE PATIENTS. THE EFFECT OF SERTRALINE TREATMENT

Previous studies have supported an association between low levels folate, vitamin B12 levels and elevated homocysteine levels as possible predictors of depression. Hyperhomocysteinemia induces free radical production, leading to alteration of oxidative lipid and protein modifications. Vitamin supplementation or antidepressants may reduce risk factors underlying depression. The aims of this study were to determine serum levels of protein carbonylation, lipid peroxidation, homocysteine, folic acid and vitamin B12 in depressive patients and to compare them with healthy controls; and to investigate the effects of sertraline (50 mg/day) treatment during 45 days. 23 depressed patients and 23 healthy controls participated in this study. Serum protein carbonylation was determined by spectrophotometric measurement of 2,4-dinitrophenylhydrason formation. Malondialdehyde levels were determined by spectrophotometric measurement of colour which was the reaction between thiobarbituric acid and malonclialdehyde. Serum homocysteine levels were measured by HPLC, and vitamin B12 and folate levels - by radioimmunoassay. There was no remarkable difference in protein carbonylation, malondialdehyde formation, homocysteine, vitamin B12 and folate levels between healthy control group and depressed patients. Sertraline treatment caused a significant decrease in malondialdehyde levels. The findings suggest that sertraline treatment caused decreasing in oxidative stress by lowering lipid peroxidation in depressed patients

Investigation of the correlation between ADMA levels and carotid artery intima-media thickness in rheumatoid arthritis patients [Romatoid artritli hastalarda ADMA düzeyleri ile karotid arter intima-media kali{dotless}nli{dotless}gi{dotless} arasi{dotless}ndaki i·lişkinin saptanmasi{dotless}]

Objective: Plasma asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, is related to increased cardiovascular risks, endothelial dysfunction and atherosclerosis. Carotid artery intima-media thickness (IMT) is closely related to the risk of coronary artery disease. We aimed to investigate plasma ADMA levels and its relation to carotid IMT in patients with rheumatoid arthritis (RA). Materials and Methods: Eighteen Turkish patients with RA (16 females, mean age: 49.44±8.88 years) and 18 age- and gender-matched healthy controls (16 females, mean age: 46.28±4.97 years) were included in the study. Measurement of IMT was done by B-mode ultrasound. Plasma ADMA levels and carotid IMT of both sides were measured in all patients and healthy controls, and the means of the two groups were compared. The correlation between ADMA levels and carotid IMT was assessed in patients with RA. Results: Plasma ADMA levels were significantly higher in patients compared to healthy controls. Although the carotid IMT values were relatively higher in the patient group than in the control group, the difference was not statistically significant. There was no significant correlation between ADMA levels and carotid IMT values. Conclusion: Our findings support the notion that plasma ADMA levels are elevated in patients with RA. Despite lack of correlation between ADMA levels and IMT in our study, ADMA levels can be used to evaluate endothelial dysfunction. © Turkish Journal of Physical Medicine and Rehabilitation, Published by Galenos Publishing

Changes In Blood Haemorheological Parameters After Submaximal Exercise In Trained And Untrained Subjects

The blood stream is affected by viscosity and many other haemorheological factors such as lipid peroxidation in the plasma and red blood cells. The aim of this study was to investigate the changes of haemorheological parameters after submaximal exercise in trained and untrained subjects. The results indicated that heart rate, lymphocyte count, erythrocyte deformability, plasma lipid peroxide levels and erythrocyte glutathione peroxidase activity are increased after submaximal exercise.Wo