Alterations in L-arginine and inflammatory markers in type 2 diabetic patients with and without microalbuminuria.

Low-grade inflammation is closely involved in the pathogenesis of type 2 diabetes and associated micro- and macrovascular complications. The nitric oxide (NO) precursor L-arginine, is relevant to diverse pathological conditions including type 2 diabetes and its complications. High sensitive-CRP (hs-CRP), neopterin and arginine levels were measured in 46 normoalbuminuric, 45 microalbuminuric type 2 diabetics and in 32 healthy controls in order to assess the relationship between markers of inflammation and L: -arginine. Hs-CRP concentrations were higher in microalbuminuric diabetic patients compared to normoalbuminuric patients and controls. Diabetics had higher serum and urine neopterin levels than controls. Urine neopterin and L-arginine levels differed significantly among diabetic patients with and without microalbuminuria. There were significant positive correlations between hs-CRP and BMI in healthy controls and diabetics with and without microalbuminuria. In microalbuminuric diabetics, hs-CRP correlated with microalbuminuria (MAU). Significant predictors for the development of microalbuminuria were higher postprandial glucose levels, lower creatinine clearance and lower serum L-arginine levels. Assessment of early markers of inflammation and endothelial function, such as neopterin and NO precursor L-arginine, may help to predict incipient nephropathy more accurately in type 2 diabetic patients.

The effects of N-acetylcysteine on oxidative stress in organophosphate poisoning model.

Organophosphate compounds act by irreversible inhibition of cholinesterase. In addition to their muscarinic, nicotinic, and central nervous system effects, some organophosphate insecticides cause oxidative stress by increasing lipid peroxidation in erythrocytes and by increasing levels of the enzymes superoxide dismutase and catalase. In this study, the effects of an antioxidant, N-acetylcysteine (NAC), in organophosphate poisoning were investigated. After obtaining Animal Ethics Committee approval, 16 male Wistar rats were divided into 2 groups. Following anesthesia, rats were tracheostomized and mechanically ventilated. Invasive hemodynamic monitoring was begun and all rats were injected with 70 mg/kg of dichlorvos (DDVP) intraperitoneally. The rats in group 1 received placebo intravenous 0.9% NaCl and the rats in group 2 received 150 mg/kg intravenous NAC. Blood samples were obtained before injection of DDVP and 60 minutes after injection to determine levels of malondialdehyde, superoxide dismutase, and catalase. Hemodynamic data and biochemistry test results were compared by analysis of variance and Wilcoxon test. P<.05 was regarded as statistically significant. Superoxide dismutase and malondialdehyde levels were significantly increased in group 1 while no difference was observed in group 2. It was concluded that organophosphate compounds might cause oxidative stress by interfering with antioxidant defense mechanisms in erythrocytes and that NAC might prevent increased lipid peroxidation. In addition to classic treatments, drugs with antioxidant effects might therefore be promising in the treatment of organophosphate poisoning.

Link between monoamine oxidase and nitric oxide.

For the last few decades, there has been extensive research and supporting evidence for the role of monoamine oxidase (MAO) activity and its' possible manipulation in the pathophysiology of neurodegenerative disorders. Although, the role of dopaminergic, noradrenergic and serotonergic systems in central nervous system (CNS) and neurodegenerative diseases have been mostly demonstrated, the intrinsic mechanisms in these systems with relation to other molecules in CNS have received less attention. A more recently discovered molecule, nitric oxide (NO) has also gained attraction in a number of physiological and pathological states. Much of this attraction is due to the role of NO as a neurotransmitter/neuromodulator in the CNS. This review will describe our current state of knowledge about the established biochemical mechanisms of MAO and NO, with particular emphasis on aging and neurodegenerative disorders. Possible intrinsic mechanisms which are likely to be of crucial importance will also be discussed and a link in between will be proposed based on the evidence derived from recent basic and clinical research.

Trace elements analysis of ascitic fluid in benign and malignant diseases.

OBJECTIVES: To evaluate differences in ascitic fluid trace element concentrations which might be useful in discrimination between benign and malignant ascites. DESIGN AND METHODS: The concentrations of copper, zinc, magnesium and iron in ascitic fluid and venous blood in 17 patients were investigated. The relationship between these trace elements and type of disease were examined. Investigations were carried out in a group of 5 males and 5 females aged 54 to 77 yr who had cirrhosis ascites and in a group of 7 females aged 41 to 76 yr with ascites due to gynecologic neoplasms. RESULTS: The mean ascitic fluid and serum concentrations of copper were significantly higher in neoplastic diseases compared to benign disease states (118,43 vs. 97,50, 91,14 vs. 26.90) (p < 0,05 and p < 0,01 respectively). The zinc levels in ascitic fluid and serum were significantly different between the groups (p < 0,01). Neoplastic patients had significantly higher ascitic fluid magnesium levels than the benign disease group (2,17 vs. 1,55, p < 0,001). The serum levels of iron were significantly lower in the neoplastic diseases group (92, 28 vs. 255, p < 0, 01). In benign diseases the concentration of zinc in ascitic fluid correlated positively with ascitic fluid copper concentrations. The concentrations of zinc and iron in malignant ascites correlate positively with the magnesium concentrations. Statistically significant negative correlations were found between ascites zinc and magnesium and magnesium and copper in cirrhotic patients and magnesium and copper in malignant diseases. CONCLUSIONS: The results showed that zinc, magnesium and iron levels were significantly different between cirrhotic and neoplastic illness. Analysis of serum and ascitic fluid trace element composition may be helpful in identifying and distinguishing the malignant and nonmalignant ascites and provides useful information on processes regulating passage of blood components into the peritoneal cavity.

Role of thiocyanate ion in metallothionein induction and in endogenous distribution of essential elements in the rat liver.

Thiocyanate is the major toxic metabolite of hydrogen cyanide, a toxic substance the organism may be exposed to as a result of cigarette smoking or industrial pollution. The complex interactions existing between metals and metallothionein induction are well known. However, the possible role of thiocyanate, which is also an anion, has not been established yet. Considering the interactions between metals and the metallothioneins, in this study the relationship between thiocyanate and the in vivo distribution of hepatic metallothionein and zinc, copper, iron, calcium, magnesium, and manganese are investigated in rats. This study implies that thiocyanate has, to some extent, an effect on the in vivo expression of metallothionein and endogenous distribution of essential elements in rat liver. Elevated levels of metallothionein and changes in hepatic concentrations of essential elements have suggested a role for thiocyanate in cellular metabolism and it might reflect a direct role of thiocyanate on alteration of cellular functional activities.