Investigation of the effectiveness of ghrelin treatment in lung tissue of rats with sepsis.

OBJECTIVE: We aimed to investigate the effects of exogenous ghrelin on cytokine and ghrelin levels, oxidant parameters, and apoptotic genes in lung tissue during sepsis. BACKGROUND: There was evidence that changes of apoptosis are linked with morbidity and mortality in sepsis. There were scarce studies on the effect of ghrelin on apoptotic genes and endogenous ghrelin levels during sepsis. METHODS: Male Wistar albino rats 200-250 g were separated into four groups; Control, LPS (5 mg/kg), Ghrelin (10 nmol/kg i.v.), and LPS+Ghrelin. Tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), and ghrelin levels were determined from lung tissue using enzyme-linked immunosorbent assay (ELISA). TNF-α, IL-10, Bcl-2, and Bax gene expressions were calculated using quantitative real-time polymerase chain reaction (RT-PCR), tissue superoxide dismutase enzyme (SOD) activities and malondialdehyde (MDA) were determined spectrophotometerically. RESULTS: TNF-α levels decreased in the LPS+Ghrelin group compared with the LPS (p < 0.001). IL-10 and MDA levels were found highly significantly increased in the LPS and LPS+Ghrelin groups (p < 0.05). Tissue SOD activities were higher in the Ghrelin and LPS+Ghrelin group compared with the LPS (p < 0.05). TNF-α, and Bax expression levels were increased in the LPS compared with the other groups. IL-10 expression levels were increased in the experimental groups compared with the controls. Bcl-2 expression levels were increased in the Ghrelin and LPS+Ghrelin compared with other groups. CONCLUSION: Ghrelin treatment attenuated LPS-induced lung injury. Treatment with ghrelin had no impact on serum and tissue ghrelin levels, but it decreased the level of proinflammatory cytokines. We found that ghrelin treatment had an antioxidant effect on SOD levels. Also, ghrelin decreased the activity of proapoptotic Bax and increased antiapoptotic Bcl-2. Our findings suggest that administration of ghrelin may attenuate damage in lung tissue during sepsis (Fig. 4, Ref. 33).

The impact of pretreatment with simvastatin on kidney tissue of rats with acute sepsis.

It has been reported that changes in cytokine levels affect mitochondrial functions, levels of hypoxia-inducible factor α (HIF-1α), and tissue damage during sepsis. We aimed to investigate the effects of simvastatin pretreatment on mitochondrial enzyme activities, and on levels of ghrelin, HIF-1α, and thiobarbituric acid reactive substances (TBARS) in kidney tissue during sepsis. Rats were separated into four groups, namely, control, lipopolysaccharides (LPS) (20 mg/kg), simvastatin (20 mg/kg), and simvastatin + LPS. We measured the levels of mitochondrial enzyme activities and TBARS in the kidney using spectrophotometry. The histological structure of the kidney sections was examined after staining with hematoxylin and eosin. Tumor necrosis factor α (TNF-α), IL-10, HIF-1α, and ghrelin immunoreactivity were examined using proper antibodies. In tissue, TNF-α (p < 0.01) and HIF-1α (p < 0.05) levels were increased in the simvastatin + LPS and LPS groups. TBARS levels were higher in the LPS group than in the other groups (p < 0.01), but they were similar in the simvastatin + LPS and control groups (p > 0.05). Ghrelin immunoreactivity was lower in the LPS group (p < 0.05) and higher in the simvastatin + LPS group than in the LPS group (p < 0.01). We observed tubular damage in the sections of the LPS group. There were no differences in mitochondrial enzyme activities between the groups (p > 0.05). We observed that pretreatment of simvastatin caused favorable changes on ghrelin and TBARS levels in rats with sepsis.

Amelioration of energy metabolism by melatonin in skeletal muscle of rats with LPS induced endotoxemia.

In the literature, few studies have investigated the effects of melatonin on energy metabolism in skeletal muscle in endotoxemia. We investigated the effects of melatonin on tissue structure, energy metabolism in skeletal muscle, and antioxidant level of rats with endotoxemia. We divided rats into 4 groups, control, lipopolysaccharide (LPS) (20 mg/kg, i.p., single dose), melatonin (10 mg/kg, i.p., three times), and melatonin + LPS. Melatonin was injected i.p. 30 min before and after the 2nd and 4th hours of LPS injection. Antioxidant status was determined by glutathione (GSH) measurement in the blood. Muscle tissue was stained using modified Gomori trichrome (MGT), succinic dehydrogenase (SDH), and cytochrome oxidase (COX) and histological scored. Also the sections were then stained with hematoxylin and eosin. The stained sections were visualized and photographed. Creatine, creatine phosphate, adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) levels were investigated using high performance liquid chromatography (HPLC) in muscle tissue. In the Melatonin + LPS group, blood GSH levels were increased compared with the LPS group (P<0.01). Melatonin reduced myopathic changes in the LPS group according to the histopathologic findings. In addition, ATP values were increased compared with the LPS group (P<0.05). Our findings showed melatonin treatment prevented muscle damage by increasing ATP and GSH levels in rats with LPS induced endotoxemia.

Relation between Endothelial Nitric Oxide Synthase Genotypes and Oxidative Stress Markers in Larynx Cancer.

Nitric oxide synthase (eNOS/NOS3) is responsible for the endothelial synthesis of nitric oxide (NO(•)). G894T polymorphism leads to the amino acid substitution from Glu298Asp that causes lower NOS3 activity and basal NO(•) production in NOS3 894T (298Asp) allele carriers compared with the GG homozygotes. NO(•) acts as an antioxidant protecting against Fenton's reaction which generates highly reactive hydroxyl radicals. Allelic variation of NOS3 may influence an individual's risk of laryngeal cancer (LC). In the current study we have examined the possible relationship between NOS3 G894T genotypes and various systemic oxidative damage markers such as protein carbonyl, advanced oxidation protein products, Cu, Zn-superoxide dismutase, thiol group fractions, and lipid hydroperoxides in LC patients. Genotyping was carried out by PCR-RFLP. In LC patients with TT genotype, Cu, Zn-superoxide dismutase activities and nonprotein thiol levels were significantly higher than the controls. In patients with GT and GG genotype, high levels of lipid hydroperoxides showed statistical significance when compared to controls. Our results indicate a potential relationship among G894T polymorphism of NOS3, and impaired redox homeostasis. Further studies are required to determine the role of NOS3 gene polymorphism and impaired plasma redox homeostasis.

ACE gene polymorphism in peripheral vascular disease.

Peripheral vascular disease is an atherosclerotic process. It has been suggested that angiotensin converting enzyme insertion/deletion polymorphism is associated with atherosclerosis. The aim of this study was to investigate the role of the insertion/deletion polymorphism of the angiotensin-converting enzyme in Turkish patients with peripheral vascular disease in Western part of Turkey. We also investigated the relationship between serum angiotensin converting enzyme activity and distribution of genotypes in both patients and control group. The study group consisted of 78 patients with peripheral vascular disease. The control group consisted of 73 healthy adults. Serum angiotensin converting enzyme activities in patients were higher than those of the control group (p<0.05). Angiotensin converting enzyme genotype frequencies in patients were observed as 28.2%, 18% and 53.8% for DD, II and ID polymorphism, respectively. These frequencies in controls were 42.5%, 20.5% and 37% for DD, II and ID, respectively. Serum angiotensin converting enzyme activities in both groups with II genotype were significantly lower than those with ID and DD genotype (p<0.05). Although conflicting results have been reported about this polymorphism in patients with peripheral vascular disease, we suggest that the angiotensin converting enzyme ID genotype may be a risk factor for peripheral vascular disease.

Combined effects of ACE and MMP-3 polymorphisms on migraine development.

Migraine is a primary headache disorder which involves both genetic and environmental components. Since angiotensin-converting enzyme (ACE) and matrix metalloproteinase (MMP) share the same homology, we investigated whether the MMP-3 and ACE I/D gene variants are involved in migraine risk and whether the ACE variant might act in combination with the MMP-3 genetic variant in patients with migraine. This is the first study to evaluate the association between MMP-3 and ACE polymorphisms, and migraine. Genotypes were determined by polymerase chain reaction. The frequencies of 5A5A genotypes of the MMP-3 and D allele of ACE were significantly elevated, but II genotypes of the ACE and 6A allele of MMP-3 significantly decreased in all patients. The combined DD/5A5A and ID/5A5A genotypes increased the risk of migraine. Individuals who were homozygous for the deletion (D) allele showed increased ACE activity. Subjects with the 5A5A genotype and/or D allele or with the combined DD/5A5A or ID/5A5A might be more susceptible to migraine development. In contrast, subjects with the II and/or 6A6A genotypes may be protected from migraine development. The greater activity of the 5A5A and DD genotypes might result in vascular reactivity that is more pronounced in migraine. Taken together, our data suggest that numerous genes may influence ACE activity. Discovery of new genes might better clarify the pathogenesis of migraine and open an avenue to therapeutic strategies against migraine.

Age-dependent changes in liver ganglioside levels.

Gangliosides, sialic acid-containing glycosphingolipids, are found in the outer layer of the plasma membrane of all vertebrate tissue cells; the highest concentration is in the central nervous system. In recent years, there has been research on the distribution and quantity of gangliosides in extra-neuronal tissues, such as liver, kidney and intestine. Since liver is the main source of gangliosides that are carried by lipoproteins in the blood, we examined the effect of development and aging on gangliosides in liver tissue. The relationship was investigated between GM1, GD3, GD1a, GD1b, GT1b ganglioside fractions and the aging process in liver tissue of Wistar-Albino rats aged 3, 6, 12 and 24 months. HPLC analysis of liver gangliosides showed the following results: Compared to 3 month-old rats, the GM1 fraction was decreased by 50% in 6 month-old rats, increased in 12 month-old rats and decreased in 24 month-old rats. The GD3 and GD1b fractions increased until 12 months of age and were decreased significantly (p < 0.01) in 24 month-old rats. The GD1a ganglioside fraction was significantly increased in 6 and 24 month-old rats (p < 0.01). We concluded that the increment of the polar fractions, such as GD3 and GD1b, and the variations of the other fractions in the plasma membrane of the hydrophilic liver tissue during the first 12 months were important parameters.

Protective role of immobilization on ouabain-induced arrhythmias.

The effects of the opioid-type stressor, immobilization, on severity of ouabain-induced cardiac arrhythmias and the possible involvement of serum catecholamines were investigated in rats. Immobilization significantly reduced the number of ventricular premature beats and the incidence of ventricular tachycardia episodes. The arterial serum catecholamine levels (A, NA and DA), measured immediately after the stressor application, were increased significantly and were in negative correlation with the arrhythmia parameters. Both changes were reversed by naloxone (5 mg/kg) treatment after application of immobilization. The effects observed in this study may be attributed to the actions of endogenous opioid peptides released during stress.