Effects of coenzyme Q and creatine supplementation on brain energy metabolism in rats exposed to chronic cerebral hypoperfusion.

It is known that oxidative stress and mitochondrial dysfunction both play an important role in animal models of brain ischemia. The present study was undertaken to test whether oral supplementation of coenzyme Q10 (ubiquinone) or creatine citrate could protect against brain ischemia-induced mitochondrial damage in the rats model. Brain ischemia was induced for 50 minutes with three-vessel occlusion (3-VO).

In vivo and in vitro assessment of brain bioenergetics in aging rats.

Brain energy disorders can be present in aged men and animals. To this respect, the mitochondrial and free radical theory of aging postulates that age-associated brain energy disorders are caused by an imbalance between pro- and anti-oxidants that can result in oxidative stress. Our study was designed to investigate brain energy metabolism and the activity of endogenous antioxidants during their lifespan in male Wistar rats.

New magnetic resonance spectroscopy biomarker for monitoring neurodegenerative diseases: animal models.

Creatine kinase (CK) plays a central role in energy transfer in cells with high-energy demands, and the enzyme is rather susceptible to oxidative inactivation. The aim of the present study was to investigate whether the rate constant of forward CK reaction (k(for)) is a suitable indicator of alterations in cerebral energy metabolism. We monitored k(for) in the rat brain non-invasively by in vivo phosphorus ((31)P) magnetic resonance spectroscopy (MRS).

Study of the oxidative stress in a rat model of chronic brain hypoperfusion.

A multiple analysis of the cerebral oxidative stress was performed on a physiological model of dementia accomplished by three-vessel occlusion in aged rats. The forward rate constant of creatine kinase, k(for), was studied by saturation transfer (31)P magnetic resonance spectroscopy in adult and aged rat brain during chronic hypoperfusion. In addition, free radicals in aging rat brain homogenates before and/or after occlusion were investigated by spin-trapping electron paramagnetic resonance spectroscopy (EPR).

Effects of sizofiran on endotoxin-enhanced cold ischemia-reperfusion injury of the rat liver.

Kupffer cells (KC), resident macrophages of the liver, have been strongly implicated in lipopolysaccharide (LPS)-induced liver graft injury. However, our recent study showed that sizofiran (schizophyllan glucan) (SPG), which activates KC, did not influence cold ischemia-reperfusion liver injury of LPS-exposed rats. Here we investigated some mechanisms by which SPG does not aggravate LPS-enhanced cold ischemia-reperfusion rat liver injury.

Improvement of rat liver function by energy repletion after the preservation period: implications for hepatic graft management.

We very recently showed (using a blood-free perfusion model) that cold preservation sensitized rat hepatocyte functions to rewarming ischemic injury and that the injury can be prevented by repleting high-energy adenylates in the liver by short-term oxygenated warm reperfusion. Here we investigated whether short-term reperfusion after the preservation period can improve hepatic graft function in a blood reperfusion model. Eighteen-hour cold-preserved rat livers either untreated (Group A) or pretreated by 30-min oxygenated warm reperfusion after preservation (Group B) were subjected to 20-min ischemic rewarming and then reperfused with blood.

[Liver steatosis and disorders of mitochondrial oxidative phosphorylation after experimental administration of simazine].

Background: Triazine herbicides are widely used in extensive agricultural production, however, some ecological and health hazards occur due to water and food contamination.

Aim: The aim of this study was to evaluate the effects of long-term simazine feeding on the steatosis development and the changes of liver bioenergetics in experimental animals.

Methods: A population of B6C3F1 mice were fed with simazine (2 g and 4 g/kg/day, respectively) for 35 weeks.

A study of creatine kinase reaction in rat brain under chronic pathological conditions-chronic ischemia and ethanol intoxication.

Creatine kinase reaction rates were measured by the magnetisation transfer technique in brains of healthy adult and aged rats and in rats with chronic cerebral ischemia and chronic ethanol intoxication. These measurements indicated that the rate constant of the creatine kinase reaction is significantly reduced in the case of severe chronic cerebral ischemia in aged rats. In the adult rats, during chronic ethanol intoxication after 3 weeks of administration of 3 ml of 30% ethanol once a day via a gastric tube, a significant decrease in the pseudo first-order rate constant k(for) of the creatine kinase reaction was also found.

A rapid, simple, and cost-effective method for screening liver preservation solutions in the rat.

Background: Rat liver transplantation models or isolated liver perfusion models are currently used for assessing efficacy of liver preservation methods. We tested the hypothesis that hepatocellular enzymes released into the washout solution after preservation may predict hepatic function during reperfusion and could thus be alternatively used for evaluating efficiency of liver preservation solutions. Furthermore, we applied this approach for assessing the role of Kupffer cells (KC) in preservation-induced liver damage.

Direct high-performance liquid chromatographic determination of (R)- and (S)-propranolol in rat microdialysate using on-line column switching procedures.

Two different column-switching HPLC systems (CSWs), employing restricted access material for initial pretreatment of biological samples, were developed for the determination of propranolol enantiomers in microdialysate. CSW 1 was a single-pump set-up based on an initial sample clean-up step with a RP-18 ADS precolumn coupled with an ovomucoid analytical column for direct drug enantioseparation. For the two-pump column set-up (CSW 2), a teicoplanin analytical column was applied for the enantioselective assay after initial sample pretreatment using a RP-8 ADS precolumn.

Endotoxin-induced aggravation of preservation-reperfusion injury of rat liver and its modulation.

Background/aims: In clinical transplantation, exposure of donors to gut-derived endotoxin occurs frequently and may adversely affect liver transplantation therapy. The aim of this study was to investigate: 1) whether brief exposure of rats to endotoxin before liver procurement aggravates the early phase of reperfusion injury of hepatic explants; and if so 2) whether Kupffer cell activation is a contributing factor to liver injury; and 3) whether heparin and pentoxifylline could minimize this effect.

Methods: Male Wistar rats were injected with 0.

Creatine kinase reaction rates in rat brain during chronic ischemia.

Creatine kinase reaction rates were measured by magnetisation transfer technique in the brain of healthy adult and aged rats and in the rats with mild or severe chronic cerebral ischemia. These measurements indicated that the rate constant of the creatine kinase reaction is significantly reduced in the case of chronic brain ischemia in aged rats. In contrast, occlusion of both carotid arteries in adult rats produced a slight increase in the reaction rate 4 weeks after occlusion.

Projections of the caudal ventrolateral medulla to the thoracic spinal cord in the rat.

Background: The caudal ventrolateral medulla (CVLM), an area having cardiovascular and respiratory functions, contains neurons that project to the thoracic spinal cord. It has been presumed, although never demonstrated, that the CVLM thoracic projections terminate on intercostal and sympathetic motor neurons. Using a combination of tracers, the purpose of the present study was to describe a route through which the CVLM may directly influence sympathetic and intercostal motor neurons.

Effects of blockade of Kupffer cells by gadolinium chloride on hepatobiliary function in cold ischemia-reperfusion injury of rat liver.

The mechanisms of liver injury from cold storage and reperfusion are not completely understood. The aim of the present study was to investigate: 1) whether the inactivation of Kupffer cells (KCs) by gadolinium chloride (GadCl) modulates cold ischemia-reperfusion injury of rat liver; and 2) whether cold storage of rat liver involves injury to biliary epithelial cells (BECs). Hepatobiliary function was assessed using an isolated perfused rat liver model.

[Atelocollagen/hydroxylapatite composite material as bone defect filler in an experiment on rats].

Many types of biomaterials are used as skeletal bone fillers in reconstructive surgery. An attention is paid to hydroxyapatite due to its high biocompatibility with the surrounding tissue. The paper deals with the testing of new collagen/hydroxyapatite composite material applied to the bone defect on os parietale of rats.

Dose-ranging study of NG-nitro-L-arginine pharmacokinetics in rats after bolus intravenous administration.

1. NG-nitro-L-arginine (10, 30 and 100 mg/kg) was administered intravenously to the male Wistar rat. Plasma was collected over 48, 72 and 120 h and was analysed for the drug by hplc.

[Hemodynamics, lymphatic circulation and ultrastructure of the lungs during hemodilution with blood substitutes].

The effect of substitution hemodilution on transcapillary fluid exchange in the lung was studied in experiments on 30 dogs. After administration of Ringer's solution and of oncotic solutions (3.4% and 10% Rheodextran), the lymph flow through the right lymphatic trunk was measured and the protein content in the lymph was determined.

[The physiologic significance of 2,3-diphosphoglycerate and changes in its erythrocyte levels in an experiment].

The regulatory effect of 2,3-DPG on oxygen transport and binding to hemoglobin was analyzed. Under conditions of substitution hemodilution by isooncotic 3.4% Rheodextran (Spofa), changes in the content of 2,3-DPG in arterial and venous blood were enzymatically determined over several days.