Serum ferritin elevation and acute lung injury in rats subjected to hemorrhage: reduction by mepacrine treatment

Altered responsiveness to glutamatergic modulation by MK-801 and to repeated stress of immune challenge in female dopamine transporter knockout rats

Chronic stress is a key factor in psychiatric and neurological disorders often worsening disease symptoms. In this study, a unique animal model, the dopamine transporter knockout (DAT-KO) rat exhibiting behavioral signs resembling those occurring in mania, schizophrenia, attention deficit hyperactivity disorder, and obsessive-compulsive disorder was used. We have tested the hypothesis that the hyperdopaminergic state in DAT-KO rats (i) modulates behavioral response to the NMDA antagonist MK-801 (dizocilpine) and (ii) leads to abnormal endocrine and immune activation under subchronic stress induced by an immune challenge. Glutamatergic modulation with MK-801 induced a different behavioral pattern. While the WT rats responded to MK-801 injection with a robust rise in their locomotor activity, the hyperactive DAT-KO rats exhibited reduced locomotion. Signs of chronic stress including increased basal corticosterone and aldosterone but blunted anxiety were demonstrated in rats lacking the DAT. Repeated injections of increasing doses of lipopolysaccharide (LPS, 5 days) did not modify plasma prolactin concentrations which were however significantly lower in DAT-KO than in WT rats. Concentrations of plasma high mobility group box 1 (HMGB1) protein were significantly higher in LPS-treated DAT-KO than in WT rats. The gene expression of interleukin-6 in the anterior pituitary increased under the stress induced by the immune challenge in the WT but not the DAT-KO rats. The most evident differences between the genotypes were revealed in the spleen. The splenic gene expression of interleukin-1β, interleukin-6, and HMGB1 was lower and that of ferritin was higher in DAT-KO compared to WT rats. Obtained results emphasize the functional interaction of the endocrine and immune systems with monoamine and glutamatergic neurotransmission in the mechanisms leading to behavioral alterations and psychiatric disorders associated with dopamine dysfunction.

Evaluation of lung and bronchoalveolar lavage fluid oxidative stress indices for assessing the preventing effects of safranal on respiratory distress in diabetic rats

We investigated the effects of antioxidant activity of safranal, a constituent of Crocus sativus L., against lung oxidative damage in diabetic rats. The rats were divided into the following groups of 8 animals each: control, diabetic, and three diabetic + safranal-treated (0.25, 0.50, and 0.75 mg/kg/day) groups. Streptozotocin (STZ) was injected intraperitoneally (i.p.) at a single dose of 60 mg/kg for diabetes induction. Safranal was administered (i.p.) from 3 days after STZ administration to the end of the study. At the end of the 4-week period, malondialdehyde (MDA), nitric oxide (NO) and reduced glutathione (GSH) contents, activity of superoxide dismutase (SOD), and catalase (CAT) were measured in the bronchoalveolar lavage fluid (BALF) and lung tissue. Safranal in the diabetic groups inhibited the level of MDA and NO in BALF supernatant and lung homogenate. The median effective dose (ED50) values were 0.42, 0.58, and 0.48, 0.71 mg/kg, respectively. Safranal in the diabetic groups increased the level of GSH and the activity of CAT and SOD in BALF supernatant and lung homogenate. The ED50 values were 0.25, 0.33, 0.26 in BALF and 0.33, 0.35, 0.46 mg/kg in lung, respectively. Thus, safranal may be effective to prevent lung distress by amelioration oxidative damage in STZ diabetic rats.

Ischemia/reperfusion Lung Injury Increases Serum Ferritin and Heme Oxygenase-1 in Rats

Intestinal ischemia/reperfusion (I/R) is one of common causes of acute lung injury (ALI). Early and accurate diagnosis of patients who are like to develop serious acute respiratory distress syndrome (ARDS) would give a therapeutic advantage. Ferritin and heme oxygenase-1 (HO-1) are increased by oxidative stress and are potential candidates as a predictive biomarker of ARDS. However, the mechanisms responsible for the increases of ferritin and HO-1, and their relationship to ALI, are unclear. In order to elucidate the interactions between ferritin and HO-1, we studied the changes in ferritin and HO-1 levels in serum and bronchoalveolar lavage (BAL) fluid after intestinal I/R injury in rats. Leukocyte number and protein contents in BAL fluid were elevated following I/R, and the increases were attenuated by mepacrine pretreatment. Both serum ferritin and HO-1 concentrations were progressively elevated throughout the 3 h observation period. Mepacrine pretreatment attenuated the increase of serum and BAL fluid ferritin concentrations, but did not suppress the increase of serum HO-1. Moreover, BAL fluid HO-1 levels did not change after I/R or after mepacrine pretreated I/R compared with sham rats. Unlike ferritin, HO-1 levels are not exactly matched with the ALI. Therefore, there might be a different mechanism between the changes of ferritin and HO-1 in intestinal I/R-induced ALI model.