Bacterial translocation in experimental stroke: what happens to the gut barrier?

The reasons of post-stroke infections are still incompletely understood. Bacterial translocation (BT), the passage of viable microbes across an even anatomically intact intestinal barrier, has been described in many critical illnesses. To date, it has not been studied as a source of infection in an animal stroke model.

Pharmacological preconditioning with erythropoietin reduces ischemia-reperfusion injury in the small intestine of rats.

Aims: Considering the implications that arose from several recent experimental studies using recombinant human erythropoietin in rodents, erythropoietin has been regarded as a pharmacological preconditioning agent. The purpose of the present study was to evaluate whether erythropoietin has a preconditioning effect against ischemia and reperfusion injury in the small intestine of the rat.

Main Methods: Intestinal ischemia was induced in male Wistar rats by clamping the superior mesenteric artery for 30 min, followed by reperfusion for 180 min.

Protective effects of L-arginine on rat terminal ileum subjected to ischemia/reperfusion.

Objectives: Studies have shown that nitric oxide (NO) may play a major role in sustaining mucosal integrity; however, NO has been also implicated in the pathogenesis of ischemia/reperfusion (I/R)-related tissue injury. We investigated the effects of L-arginine and NG-nitro L-arginine methyl ester (L-NAME) on the acetylcholine-induced contractile response of ileum and the levels of malondialdehyde (MDA) and reduced glutathione (GSH). Histopathological changes were also evaluated in ileal preparations.

AT1 receptor blocker candesartan-induced attenuation of brain injury of rats subjected to chronic cerebral hypoperfusion.

One of common pathophysiological states associated with central nervous system is chronic cerebral hypoperfusion (CH) that frequently occurs in conditions such as vascular dementia and Alzheimer's disease. Long term blockage of angiotensin II type 1 (AT(1)) receptor provides protection from ischemia induced injury of brain as well as reduction of cerebrovascular inflammation. Examining effect of the blockage on reduced glutathione (GSH), ascorbic acid (AA), and lipid peroxidation were of purpose in the present study.

Attenuation of contractile dysfunction by atorvastatin after intestinal ischemia reperfusion injury in rats.

Growing number of studies implicate that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have beneficial effects on ischemia/reperfusion injury that are unrelated to their cholesterol-lowering action. In the present study, we aimed to evaluate possible effects of atorvastatin on oxidative stress, neutrophil accumulation, and contractile response of terminal ileum segments in rats subjected to intestinal ischemia/reperfusion. Intestinal ischemia/reperfusion model was generated by clamping the superior mesenteric artery for 30 min followed by reperfusion for 3 h.

Pretreatment with adenosine and adenosine A1 receptor agonist protects against intestinal ischemia-reperfusion injury in rat.

Aim: To examine the effects of adenosine and A1 receptor activation on reperfusion-induced small intestinal injury.

Methods: Rats were randomized into groups with sham operation, ischemia and reperfusion, and systemic treatments with either adenosine or 2-chloro-N(6)-cyclopentyladenosine, A1 receptor agonist or 8-cyclopentyl-1,3-dipropylxanthine, A1 receptor antagonist, plus adenosine before ischemia. Following reperfusion, contractions of ileum segments in response to KCl, carbachol and substance P were recorded.

Erythropoietin stimulates wound healing and angiogenesis in mice.

Erythropoietin exerts hematopoietic effects by stimulating proliferation of early erythroid precursors. Nonhematopoietic effects of erythropoietin have also been shown. It may act as a new angiogenic factor in wound healing.

L-Arginine and melatonin interaction in rat intestinal ischemia--reperfusion.

We investigated the combinative effects of L-arginine and melatonin on the contractile responses of terminal ileum after the intestinal ischemia-reperfusion (I/R), in vivo. Male rats were subjected to mesenteric ischemia (30 min) followed by reperfusion (180 min). We have observed a dramatic decrease in spontaneous basal activity and Ach-induced contractile response.

Effect of rapid-eye-movement sleep deprivation on rat hypothalamic prostaglandins.

In this study, we investigated thyroid hormones, thyroid stimulating hormone (TSH), prostaglandin D(2) (PGD(2)) and prostaglandin E(2) (PGE(2)) levels in rapid-eye-movement (REM) sleep-deprived rats compared with controls. The aim of the present study was to detect the effect of REM sleep deprivation (RSD) especially on hypothalamic prostaglandin levels. Twenty-seven male rats were randomly assigned in three groups as dry cage control, yoked control, and RSD.

Protective effect of melatonin on contractile activity and oxidative injury induced by ischemia and reperfusion of rat ileum.

Free radicals derived from molecular oxygen have been reported to be responsible for changes in motility and mucosal damage observed in intestinal ischemia-reperfusion injury. Melatonin has been considered as an antioxidant that prevents injuries resulted from I/R in various tissues. The present study was designed to determine the effect of melatonin on the contractile responses of acetylcholine (Ach) and KCl, on malondialdehyde (MDA), a product of lipid peroxidation, and reduced glutathione (GSH) levels and to assess histopathological changes in the smooth muscle of terminal ileum subjected to ischemia-reperfusion.

Beneficial effects of melatonin on reperfusion injury in rat sciatic nerve.

Studies have shown that ischemia-reperfusion (I/R) produces free radicals leading to lipid peroxidation and to damage of the nervous tissue. Melatonin, a main secretory product of the pineal gland, has free radical scavenging and antioxidant properties and has been shown to diminish I/R injury in many tissues. There are a limited number of studies related to the effects of melatonin on I/R injury in the peripheral nervous system.

Effects of L-arginine and NG-nitro L-arginine methyl ester on lipid peroxide, superoxide dismutase and nitrate levels after experimental sciatic nerve ischemia-reperfusion in rats.

Nitric oxide (NO) has been reported to function in both cytoprotective and cytotoxic tissue ischemia-reperfusion (I/R). In this study, we evaluated the effects of L-arginine, the substrate for NO, and NG-nitro L-arginine methyl ester (L-NAME), NO synthase (NOS) inhibitor on super oxide dismutase (SOD) enzyme activity, malondialdehyde (MDA), a marker of lipid peroxidation, nitrate levels, and histopathological structure in rat sciatic nerve 2 h after ischemia, followed by 3 h of reperfusion. Reperfusion resulted in a significant increase in lipid peroxidation level and a decrease in nitrate level of the sciatic nerve.