3D Hyaluronic Acid Hydrogels for Modeling Oligodendrocyte Progenitor Cell Behavior as a Function of Matrix Stiffness.

The lack of regenerative solutions for demyelination within the central nervous system motivates the development of strategies to expand and drive the bioactivity of the cells, including oligodendrocyte progenitor cells (OPCs), that ultimately give rise to myelination. In this work, we introduce a 3D hyaluronic acid (HA) hydrogel system to study the effects of microenvironmental mechanical properties on the behavior of OPCs. We tuned the stiffness of the hydrogels to match the brain tissue (storage modulus 200-2000 Pa) and studied the effects of stiffness on metabolic activity, proliferation, and cell morphology of OPCs over a 7 day period. Although hydrogel mesh size decreased with increasing stiffness, all hydrogel groups facilitated OPC proliferation and mitochondrial metabolic activity to similar degrees. However, OPCs in the two lower stiffness hydrogel groups (170 ± 42 and 794 ± 203 Pa) supported greater adenosine triphosphate levels per cell than the highest stiffness hydrogels (2179 ± 127 Pa). Lower stiffness hydrogels also supported higher levels of cell viability and larger cell spheroid formation compared to the highest stiffness hydrogels. Together, these data suggest that 3D HA hydrogels are a useful platform for studying OPC behavior and that OPC growth/metabolic health may be favored in lower stiffness microenvironments mimicking brain tissue mechanics.

Engineering biomaterial microenvironments to promote myelination in the central nervous system.

Promoting remyelination and/or minimizing demyelination are key therapeutic strategies under investigation for diseases and injuries like multiple sclerosis (MS), spinal cord injury, stroke, and virus-induced encephalopathy. Myelination is essential for efficacious neuronal signaling. This myelination process is originated by oligodendrocyte progenitor cells (OPCs) in the central nervous system (CNS). Resident OPCs are capable of both proliferation and differentiation, and also migration to demyelinated injury sites. OPCs can then engage with these unmyelinated or demyelinated axons and differentiate into myelin-forming oligodendrocytes (OLs). However this process is frequently incomplete and often does not occur at all. Biomaterial strategies can now be used to guide OPC and OL development with the goal of regenerating healthy myelin sheaths in formerly damaged CNS tissue. Growth and neurotrophic factors delivered from such materials can promote proliferation of OPCs or differentiation into OLs. While cell transplantation techniques have been used to replace damaged cells in wound sites, they have also resulted in poor transplant cell viability, uncontrollable differentiation, and poor integration into the host. Biomaterial scaffolds made from extracellular matrix (ECM) mimics that are naturally or synthetically derived can improve transplanted cell survival, support both transplanted and endogenous cell populations, and direct their fate. In particular, stiffness and degradability of these scaffolds are two parameters that can influence the fate of OPCs and OLs. The future outlook for biomaterials research includes 3D in vitro models of myelination / remyelination / demyelination to better mimic and study these processes. These models should provide simple relationships of myelination to microenvironmental biophysical and biochemical properties to inform improved therapeutic approaches.

Protective effects of amifostine, curcumin and caffeic acid phenethyl ester against cisplatin-induced testis tissue damage in rats.

Cisplatin is an effective antineoplastic drug that is usually used to treat a number of different types of cancer in the clinic. One of the most notable side effects of cisplatin use is infertility. The present study was designed to determine the non-oxidative testicular effects caused by the use of cisplatin in rats. The rats were randomly allocated to the experimental groups. The untreated rats represented the control group (group I) and the treatment groups were as follows: cisplatin alone (group II), cisplatin+amifostine (group III), cisplatin+curcumin (group IV), and cisplatin+caffeic acid phenethyl ester (CAPE; group V). The present study observed that following cisplatin administration, the expression of nuclear factor-κB (NF-κß)/p65, caspase-3 and 8-deoxyguanosine (8-OHdG) increased in germinal epithelium and Leydig cells. However, the expression of these markers decreased in groups III-V, most notably in the group treated with amifostine. cisplatin induced-damage was countered by amifostine and curcumin. The results revealed that the activation of NF-κB, caspase-3 and 8-OHdG had a significant role in cisplatin-induced testicular toxicity. Thus, amifostine, curcumin and, to a lesser extent, CAPE have the potential for use as therapeutic adjuvants in cisplatin-induced testis injury.

Liver 5-HT7 receptors: A novel regulator target of fibrosis and inflammation-induced chronic liver injury in vivo and in vitro.

BACKGROUND AND AIM: Hepatocellular cancer (HCC) is the sixth most common cancer and liver fibrosis is strongly associated with HCC. Treatment options are limited, and preventive strategies should be developed. An important step in the beginning of liver fibrosis is a strong inflammatory response. 5-HT7 is the last recognized member of the serotonin receptor family and is expressed in both central nerve system and peripheral system and have a lot of functions like learning, memory, smooth muscular relaxation, in the control of circadian rhythms and thermoregulation, pain and migraine, schizophrenia, anxiety, cognitive disturbances, and even inflammation. METHODS: We therefore examined the biochemical, histopathological and molecular effects of the 5-HT7 receptor agonist and antagonist on inflammatory liver fibrogenesis in animal models of progressive cirrhosis: a mouse model induced by carbon tetrachloride (CCl4) and in Hep3b cells. RESULTS: 5-HT7 expression was observed in the liver in vivo and in vitro in CCl4-induced damage. 5-HT7 receptor agonist but not the antagonist reduced liver markers in mice and in Hep3b cells in carbon tetrachloride (CCl4) induced damage. 5-HT7 agonist, but not antagonist, protected liver tissue from oxidative stress in fibrosis. 5-HT7 agonist but not antagonist induces anti-inflammatory, anti-fibrinotic and anti-cytokine features in liver fibrosis in vivo and in vitro. CONCLUSIONS: 5-HT7 receptors have modulatory function and are an up-and-coming pharmacological target in the inflammatory fibrotic process. 5-HT7 receptor agonist LP-44 showed significant hepatoprotective effects against liver fibrosis, and LP-44 might become a useful therapeutic target for chronic liver inflammation and fibrosis.

Protective effects of estrogen and bortezomib in kidney tissue of post-menopausal rats: an ultrastructural study.

PURPOSE: Symptoms and disorders related to menopause and its associated estrogen deficiency have become a considerable health concern worldwide. Ovarian hormone depletion/estrogen deficiency can be usefully studied using animal models after removal of the ovaries [ovariectomy (Ovx)]. This study assessed renal changes after Ovx-induced estrogen deficiency in a rat model. METHODS: Rats were randomly allotted into one control group (group I, healthy) and three study groups (group II, Ovx group; group III, Ovx +17ß-estradiol group; and group IV, Ovx + bortezomib group). RESULTS: In the Ovx group (group II), thickening of glomerular capillary walls, narrowing of Bowman's capsular space, glomerular hypertrophy, atrophic tubules, and loss of the basal membranes of the tubules were observed. Mesangial cell proliferation was observed, particularly in the glomerulus. Immunohistochemical (IHC) staining studies in this group showed dense staining in the mesangial cells, tubular cell Nf-KB/p65, and caspase-3. Groups III and IV (Ovx +17ß-estradiol and Ovx + bortezomib) showed decreased NF-kB/p65 and caspase-3 expression compared with the Ovx group (p < 0.05). CONCLUSION: In renal failure related to estrogen deficiency caused by Ovx, 17ß-estradiol and bortezomib have a protective effect on renal tissue.

Inhalation of mercury vapor can cause the toxic effects on rat kidney.

Dental amalgam has been used in dentistry as a filling material. The filler comprises mercury (Hg). It is considered one of the most important and widespread environmental pollutants, which poses a serious potential threat for the humans and animals. However, mercury deposition affects the nervous, cardiovascular, pulmonary, gastrointestinal, and especially renal systems. In most animals' species and humans, the kidney is one of the main sites of deposition of mercury and target organ for its toxicity. In this study, the effects of mercury intake on kidney in rats were searched. For the this purpose; we used 24 adult female Wistar albino rats (200 g in weight) obtained from Experimental Research and Application Center of Atatürk University with ethical approval. Besides, they were placed into a specially designed glass cage. Along this experiment for 45 days, subjects were exposed to (1 mg/m(3)/day) mercury vapor. However, no application was used for the control subjects. At the end of the experiment, kidney samples were obtained from all subjects and processed for routine light microscopic level and stereological aspect were assessed. Finally, according to our results, mercury affects the histological features of the kidney. That means, the severe effects of mercury has been shown using stereological approach, which is one of the ideal quantitative methods in the current literature. In this study, it was detected that chronic exposure to mercury vapor may lead to renal damage and diseases in an experimental rat model.

Astrocyte/neuron ratio and its importance on glutamate toxicity: an in vitro voltammetric study.

The purpose of this study was to clarify the relationship between neuron cells and astrocyte cells in regulating glutamate toxicity on the 10th and 20th day in vitro. A mixed primary culture system from newborn rats that contain cerebral cortex neurons cells was employed to investigate the glutamate toxicity. All cultures were incubated with various glutamate concentrations, then viability tests and histological analyses were performed. The activities of glutamate transporters were determined by using in vitro voltammetry technique. Viable cell number was decreased significantly on the 10th day at 10(-7) M and at 10(-6) M glutamate applications, however, viable cell number was not decreased at 20th day. Astrocyte number was increased nearly six times on the 20th day as compared to the 10th day. The peak point of glutamate reuptake capacity was about 2 × 10(-4) M on the 10th day and 10(-3) M on the 20th day. According to our results, we suggested that astrocyte age was important to maintain neuronal survival against glutamate toxicity. Thus, we revealed activation or a trigger point of glutamate transporters on astrocytes due to time since more glutamate was taken up by astrocytes when glutamate transporters on the astrocyte were triggered with high exogenous glutamate concentrations. In conclusion, the present investigation is the first voltammetric study on the reuptake parameters of glutamate in vitro.

Effects of Administration of Amlodipine and Lacidipine on Inflammation-Induced Bone Loss in the Ovariectomized Rat.

This study was performed to evaluate the possible protective effect of two calcium channel blocker's "lacidipine (LAC) and amlodipine (AML)" on bone metabolism in an experimental ovariectomized and inflammation-induced osteoporosis rat model (OVXinf). For the purpose of this study, the rats were divided into eight groups, each containing eight rats: sham-operated control (group 1, SH), sham + inflammation (group 2, SHinf), ovariectomy (group 3, OVX), ovariectomy + inflammation (group 4, OVXinf), ovariectomy + LAC 4 mg/kg (group 5, OVX + LAC), ovariectomy + inflammation + LAC 4 mg/kg (group 6, OVXinf + LAC), ovariectomy + AML 5 mg/kg (group 7, OVX + AML), ovariectomy + inflammation + AML 5 mg/kg (group 8, OVXinf + AML). The levels of osteocalcin and osteopontin decreased in OVXinf + LAC and OVXinf + AML groups. The serum levels of TNF-α, IL-1ß, and IL-6 were increased significantly in the OVXinf rats compared with the SH group. Gene expression levels of the osteogenic factor runt-related transcription factor 2 (Runx2) and type I collagen 1A1 (Col1A1) significantly decreased in the OVXinf group, when compared with the control group. AML or LAC administrations increased the levels of Runx2 and Col1A1. These results suggest that amlodipine and lacidipine may be a novel therapeutic target for radical osteoporosis treatment in hypertensive patients.

Morphological and antioxidant impairments in the spinal cord of male offspring rats following exposure to a continuous 900MHz electromagnetic field during early and mid-adolescence.

The effects of devices emitting electromagnetic field (EMF) on human health have become the subject of intense research among scientists due to the rapid increase in their use. Children and adolescents are particularly attracted to the use of devices emitting EMF, such as mobile phones. The aim of this study was therefore to investigate changes in the spinal cords of male rat pups exposed to the effect of 900MHz EMF. The study began with 24 Sprague-Dawley male rats aged 3 weeks. Three groups containing equal numbers of rats were established-control group (CG), sham group (SG) and EMF group (EMFG). EMFG rats were placed inside an EMF cage every day between postnatal days (PD) 21 and 46 and exposed to the effect of 900MHz EMF for 1h. SG rats were kept in the EMF cage for 1h without being exposed to the effect of EMF. At the end of the study, the spinal cords in the upper thoracic region of all rats were removed. Tissues were collected for biochemistry, light microscopy (LM) and transmission electron microscopic (TEM) examination. Biochemistry results revealed significantly increased malondialdehyde and glutathione levels in EMFG compared to CG and SG, while SG and EMFG catalase and superoxide dismutase levels were significantly higher than those in CG. In EMFG, LM revealed atrophy in the spinal cord, vacuolization, myelin thickening and irregularities in the perikarya. TEM revealed marked loss of myelin sheath integrity and invagination into the axon and broad vacuoles in axoplasm. The study results show that biochemical alterations and pathological changes may occur in the spinal cords of male rats following exposure to 900MHz EMF for 1h a day on PD 21-46.

Protective effects of beta glucan in brain tissues of post-menopausal rats: a histochemical and ultra-structural study.

Decline of estrogen during menopause has been associated with numerous significant changes that have been linked to many pathophysiological complications. In addition, ovarian hormone deficiency increases the production of reactive oxygen radicals which could result in oxidative stress and cell damage. While estrogen therapy is often considered to overcome the behavioral and physiological shortcomings, antioxidants are gaining popularity for their beneficial property. For this purpose, in the present study, utilizing the antioxidant properties of beta glucan has been examined in treatment of menopause induced oxidative stress in cerebral neurons. Four groups of female Wistar rats were used: control, ovariectomy, ovariectomy + estrogen treated and ovariectomy + beta glucan treated. We observed a significant increase in neural degeneration in ovariectomized rats as compared to controls. Moreover, increased oxidative stress in the brains of the ovariectomized rats has been detected by performing immunohistochemical analysis. A large number of immuno-positive cerebral neurons have been observed in ovariectomy group rat brains. Interestingly, providing beta glucan treatment to ovariectomized rats reduced the number of degenerated neurons. Our study is the first to examine light and electron microscopic examination and immunohistochemical and stereological analysis of estrogen depletion in rats and to test protective role of beta glucan in the experimental study.

The protective effects of beta-carotene against ischemia/reperfusion injury in rat ovarian tissue.

INTRODUCTION: Beta-carotene is a well-known antioxidant and precursor of Vitamin A that has a preventative role in the oxidative damage process. Our aim was to investigate the possible preventive effects of beta-carotene on oxidative damage via experimental ischemia and ischemia-reperfusion models in rat ovaries. MATERIALS AND METHODS: A traumatic vascular clamps were used for 3h to induce ischemia (Group 2, 3, 4, 5, 6, 7). The clamps were then removed to allow reperfusion for 3h (Group 3, 6, 7). Sham-operated rats (Group 1) underwent laparotomy without the induction of ischemia/reperfusion injury. Real-Time-PCR was performed to determine IL-1-beta, IL-6 and iNOS expression levels. Histopathological (H&E) and immunohistochemical staining (NF-kß p65) processes were then performed. Finally, SOD, GSH, and MDA levels were determined. RESULTS: Intense hemorrhagic areas were observed in both the ischemia and ischemia/reperfusion groups, whereas minimal hemorrhage was observed in the treatment groups. The ischemia and ischemia/reperfusion groups exhibited extreme immunoreactivity, detected by NF-kß p65 staining; this reactivity decreased after the application of beta-carotene. The expression of IL-1-beta, IL-6, and iNOS in the injury groups increased significantly, whereas a dose-dependent improvement was observed in the treatment groups. Finally, MDA levels increased significantly and SOD and GSH levels decreased drastically in the injury groups. However, these values obtained from I/R groups were normalized after beta-carotene treatment. DISCUSSION: In this study, we demonstrated via molecular and biochemical parameters the protective effect of beta-carotene, which is a potent antioxidant, on the experimental ischemia-reperfusion model.

Investigation of the effect of telmisartan on experimentally induced peripheral nerve injury in rats.

AIM: The aim of this study was to investigate the effects of telmisartan on nerve healing in a rat peripheral nerve injury model. MATERIAL AND METHOD: Thirty adult male Wistar albino rats were divided into five groups: healthy, axonotmesis, anastomosis, axonotmesis+10 mg/kg telmisartan and anastomosis+10 mg/kg telmisartan. Walking track analyses were performed 4 weeks after the surgery. The right sciatic nerves of all the animals were examined histopathologically, stereologically and molecularly. RESULTS: Many badly damaged axons were detected in the axonotmesis group, in addition to enlarged spaces between the axons. In the anastomosis group, both ir- regular and degenerated axons at different severities were observed. The sections of the telmisartan group after the axonotmesis were similar to those of the healthy group. The sections of the telmisartan group after the anastomosis were similar to those of the healthy group and the telmisartan group after the axonotmesis. Interleukin-1 beta (IL-1ß) gene expression increased in both the axonotmesis and the anastomosis groups when compared with the healthy group. Telmisartan had a significant down-regulatory effect on IL-1ß expression. Caspase-3 mRNA expression was significantly increased in the anastomosis group, and the administration of telmisartan in this group significantly decreased this rise in caspase-3 mRNA expression. As a functional outcome, telmisartan also increased the walking distance of the rats after axonotmesis and anastomosis. CONCLUSION: The histopathological, stereological, functional and molecular data suggest that telmisartan improves nerve regeneration in peripheral nerve injuries by inhibiting inflammatory cytokine IL-1ß and apoptotic caspase-3.

The effects of prenatal exposure to a 900-MHz electromagnetic field on the 21-day-old male rat heart.

The growing spread of mobile phone use is raising concerns about the effect on human health of the electromagnetic field (EMF) these devices emit. The purpose of this study was to investigate the effects on rat pup heart tissue of prenatal exposure to a 900 megahertz (MHz) EMF. For this purpose, pregnant rats were divided into experimental and control groups. Experimental group rats were exposed to a 900 MHz EMF (1 h/d) on days 13-21 of pregnancy. Measurements were performed with rats inside the exposure box in order to determine the distribution of EMF intensity. Our measurements showed that pregnant experimental group rats were exposed to a mean electrical field intensity of 13.77 V/m inside the box (0.50 W/m(2)). This study continued with male rat pups obtained from both groups. Pups were sacrificed on postnatal day 21, and the heart tissues were extracted. Malondialdehyde, superoxide dismutase and catalase values were significantly higher in the experimental group rats, while glutathione values were lower. Light microscopy revealed irregularities in heart muscle fibers and apoptotic changes in the experimental group. Electron microscopy revealed crista loss and swelling in the mitochondria, degeneration in myofibrils and structural impairments in Z bands. Our study results suggest that exposure to EMF in the prenatal period causes oxidative stress and histopathological changes in male rat pup heart tissue.

Ultra-structural changes and apoptotic activity in cerebellum of post-menopausal-diabetic rats: a histochemical and ultra-structural study.

Diabetes mellitus (DM) is one of the most common and chronic diseases, especially in post-menopausal periods. Neuro-degeneration occurs more frequently in post-menopausal diabetics. Therefore, we investigated ovariectomized rats cerebellar cortex response to the estradiol deficiency and hyperglycemia. For the ovariectomy, the rats were bilaterally ovariectomized, and then DM induced by a single dose of Alloxan monohydrate injection in ovariectomy or/and diabetic groups. During light and electron microscopic examination, degenerated Purkinje cells membrane, swollen organelles, degenerated mitochondria, edema formation and vacuolization were seen in the ovariectomy and ovariectomy-diabetic groups sections. In addition, increased apoptotic activity was observed in the ovariectomy and ovariectomy-diabetic groups compared to the control group. We demonstrated that estradiol and insulin deficiency can affect the cerebellar cortex, which support the hypothesis that the execution of neuronal damages in post-menopausal diabetics. Also, diabetes and menopause are major risks factors for many disorders including nervous system and the number of post-menopausal-diabetics are increasing world-wide.

Protective effect of L-carnitine in a rat model of retinopathy of prematurity.

AIM: To investigate the effects of L-carnitine (LC) on rats with oxygen-induced retinopathy. MATERIALS AND METHODS: The study was conducted on 40 Sprague Dawley rat pups. The rat pups were randomly divided into 4 groups: group 1 (n = 10) the healthy control group with intraperitoneal 0.1 mL/day physiological saline injection; group 2 (n = 10), exposed to hyperoxygen, did not receive LC but received 0.1 mL/day physiological saline intraperitoneally; group 3 (n = 10), exposed to hyperoxygen and received 100 mg/kg/day LC intraperitoneally; group 4 (n = 10), exposed to hyperoxygen and received 200 mg/kg/ day LC intraperitoneally. After postnatal day 20, the rat pups were killed and an histological examination was performed on the eyes, in addition to the detection of plasma malondialdehyde (MDA) levels. RESULTS: The retinal and choroidal histopathological changes due to hyperoxygen were less in group 3 and minimal in group 4 compared with group 2. Compared with the healthy control group, the increase in the MDA levels in group 2 was significant (P <0.05). Compared with group 2 there was a significant (P < 0.05) decrease in the MDA levels in groups 3 and 4. CONCLUSION: LC has beneficial effects on oxygen-induced retinopathy in rats in terms of histopathological changes and MDA levels.

Effects of intraocular rifampicin on retinal ganglion cell structure: a stereological and histopathological study.

AIM: To determine the histopathological changes of rifampicin applied intravitreally on retinal ganglion cells by means of stereological and histopathological methods. METHODS: For this study twenty-four New Zealand adult rabbits were divided into four groups (n=6 for each group). 50µg/0.1mL (group 1), 100µg/0.1mL (group 2), 150µg/0.1mL (group 3) and 200µg/0.1mL (group 4), rifampicin were injected into the vitreous of the right eyes of animals, their left eyes were used as control (group 5). After the 28(th) day of application, animals were anesthetised with xylazine (8mg/kg, IM) and then their eyes were enucleated immediately. Patterns were taken away and eyes were prepared for both stereological and electromicroscopic observation. RESULTS: Depending on the high dose of rifampicin, some histopathological changes such as cytoplasmic dilatation and damaged membrane were observed on the electromicroscopic level. Using quantitative examination, which was done at the light microscopic level, it was shown that the number of neurons decreased linearly as rifampicin dose increased when compared with the control group. CONCLUSION: Based on these findings, low-dose rifampicin (50µg/0.1mL) may be useful for treatment of the ocular diseases.

Inflammation and peripheral 5-HT7 receptors: the role of 5-HT7 receptors in carrageenan induced inflammation in rats.

The aim of this study was: (1) to investigate possible role for 5-HT7 receptors in carrageenan induced inflammatory paw oedema in rats; (2) to determine the presence of 5-HT7 receptors in rat paw tissue; (3) to observe the effects of 5-HT7 receptor agonist and antagonist administration on inflammation; and (4) to determine a unique mechanism for inflammatory processes via 5-HT7 receptors. Effects of 5-HT7 receptor agonist, antagonist and indomethacin were investigated in carrageenan induced paw oedema in rats. Blood and tissue samples were collected and evaluated biochemically for serum cytokine levels, tissue oxidant-antioxidant balance and histopathologically for inflammatory cell accumulation. We performed Real Time PCR analyses for tissue 5-HT7 receptor and COX mRNA expressions. The 5-HT7 receptor agonist AS-19 exerted significant anti-inflammatory effect both alone and in combination with indomethacin. Antagonist, SB269970, did not affect inflammation alone but decreased the effects of agonist when co-administered. 5-HT7 mRNA levels were higher in the carrageenan group than healthy control. Carrageenan+indometacin group decreased the mRNA expression of 5-HT7 when compared to carrageenan group. While agonist administration decreased 5-HT7 mRNA expression when compared to carrageenan group. Agonist decreased paw COX expression. Agonist also decreased serum cytokine levels and tissue oxidative stress. In conclusion, this study demonstrated for the first time that 5-HT7 receptors are expressed in rat paw tissue and that this expression responds to inflammatory stimuli. The 5-HT7 receptor may be a promising new therapeutic target for prevention of inflammation and inflammatory disorders and may also provide a new glimpse into inflammation pathophysiology.

Peripheral 5-HT7 receptors as a new target for prevention of lung injury and mortality in septic rats.

Sepsis is a complex pathophysiological event involving metabolic acidosis, systemic inflammatory response syndrome, tissue damage and multiple organ dysfunction syndrome. Although many new mechanisms are being investigated to enlighten the pathophysiology of sepsis, there is no effective treatment protocol yet. Presence of 5-HT7 receptors in immune tissues prompted us to hypothesize that these receptors have roles in inflammation and sepsis. We investigated the effects of 5-HT7 receptor agonists and antagonists on serum cytokine levels, lung oxidative stress, lung histopathology, nuclear factor κB (NF-κB) positivity and lung 5-HT7 receptor density in cecal ligation and puncture (CLP) induced sepsis model of rats. Agonist administration to septic rats increased survival time; decreased serum cytokine response against CLP; decreased oxidative stress and increased antioxidant system in lungs; decreased the tissue NF-κB immunopositivity, which is high in septic rats; and decreased the sepsis-induced lung injury. In septic rats, as a result of high inflammatory response, 5-HT7 receptor expression in lungs increased significantly and agonist administration, which decreased inflammatory response and related mortality, decreased the 5-HT7 receptor expression. In conclusion, all these data suggest that stimulation of 5-HT7 receptors may be a new therapeutic target for prevention of impaired inflammatory response related lung injury and mortality.

The protective effect of amiodarone in lung tissue of cecal ligation and puncture-induced septic rats: a perspective from inflammatory cytokine release and oxidative stress.

Sepsis is a serious medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. Amiodarone is a class III antiarrhythmic agent, a multichannel blocker (Ca++, Na+, and K+), and a noncompetitive α- and ß-adrenergic blocker in cardiac cells. The present study aimed to determine whether amiodarone was protective against experimentally induced cecal ligation and puncture sepsis in rat lung tissue. The relationship between its probable protective effect and antioxidant/anticytokine action biochemically and histopathologically was also examined. Five groups of rats were used, each composed of 20 rats: (1) the sham-operated control group; (2) the CLP group; (3) the 25-mg/kg amiodarone-treated control healthy group; (4) the 50-mg/kg amiodarone-treated CLP group; and (5) the 50-mg/kg amiodarone-treated CLP group. A CLP polymicrobial sepsis model was applied to the rats. All groups were sacrificed 16 h later, and lung and blood samples were analyzed histopathologically and biochemically. Twenty-five and 50 mg/kg amiodarone decreased the level of interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α in serum and 8-iso-prostaglandin F2α level in lung tissue. They increased the activities of superoxide dismutase and levels of total glutathione in lung tissues of rats. Histopathological scores and examinations were in accordance with the biochemical results. Histopathological analysis revealed significant differences in inflammation scores between the sepsis group and the other groups. The CLP + amiodarone 50 mg/kg group had the lowest inflammation score among CLP groups. Our results indicate that administration of amiodarone prevented oxidative stress and cytokine action and protected lung tissue during sepsis cascade.

Protective effects of lithium: a new look at an old drug with potential antioxidative and anti-inflammatory effects in an animal model of sepsis.

Sepsis is the systemic response of an organism against microorganisms and toxins. Lithium is a therapeutic agent used for bipolar disorder and neurodegenerative disease, and it exerts pleiotropic effects on various cellular processes. The present study aimed to determine the effect of lithium on cecal ligation and puncture (CLP)-induced tissue injury in the lungs, by inhibiting the pro-inflammatory cytokine response, and the generation of reactive oxygen species (ROS) triggered by polymicrobial sepsis. Five groups of 20 rats each were used: 1) sham-operated control group; 2) CLP group; 3) 50mg/kg lithium-treated control healthy group; 4) 25 mg/kg lithium-treated CLP group; and 5) 50 mg/kg lithium-treated CLP group. A CLP polymicrobial sepsis model was applied to the rats. All rat groups were killed 16 h later, and lung and blood samples were analyzed histopathologically and biochemically. The 25 and 50 mg/kg of lithium decreased the level of interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), and the tumor necrosis factor-α (TNF-α) in the serum, and the 8-iso-prostaglandin F2α (8-ISO) level in lung tissue. The lithium also increased the activity of superoxide dismutase (SOD) and the total levels of glutathione (GSH) in the lung tissues of rats. The histopathological scores and examinations were in accordance with the biochemical results, and revealed significant differences in the inflammation scores between the sepsis group and the other groups. The CLP+lithium 50mg/kg group had the lowest inflammation score among the CLP groups. Our results indicated that the therapeutic administration of lithium prevented oxidative stress changes and cytokine changes, and also protected vital tissues.