Erdogan Kocamaz

Sulfite leads to neuron loss in the hippocampus of both normal and SOX-deficient rats.

Sulfites are compounds commonly used as preservatives in foods, beverages and pharmaceuticals. Sulfite is also endogenously generated during the metabolism of sulfur-containing amino acids and drugs. It has been shown that sulfite is a highly toxic molecule. Many studies have examined the effects of sulfite toxicity, but the effect of ingested sulfite on the number of neurons in the hippocampus has not yet been reported. The present study was undertaken to investigate the effect of ingested sulfite on pyramidal neurons by counting cells in CA1 and CA3-2 subdivisions of the rat hippocampus. For this purpose, rats were assigned to one of four groups (6 rats per group): control (C), sulfite (S), deficient (D) and deficient+sulfite (DS). Sulfite oxidase deficiency was established by feeding rats a low molybdenum diet and adding 200ppm tungsten (W) to their drinking water. Sulfite (70mg/kg) was also administered to the animals via their drinking water. At the end of the experimental period, the rats were sacrificed by exsanguination under anesthesia, and their brains and livers quickly removed. The livers were used for a SOX activity assay, and the brains were used for neuronal counts in a known fraction of the CA1 and CA3-2 subdivisions of the left hippocampus using the optical fractionator method, which is a stereological method. The results showed that sulfite treatment caused a significant decrease in the total number of pyramidal neurons in three subdivisions of the hippocampus (CA1 and CA3-2) in the S, D and DS groups compared with the control group. It is concluded that exogenous administration of sulfite causes loss of pyramidal neurons in CA1 and CA3-2 subdivisions in both normal and SOX deficient rat hippocampus. This finding provides supporting evidence that sulfite is a neurotoxic molecule.

Implication of C-type natriuretic peptide-3 signaling in glycosaminoglycan synthesis and chondrocyte hypertrophy during TGF-β1 induced chondrogenic differentiation of chicken bone marrow-derived mesenchymal stem cells.

This study investigated the involvement of CNP-3, chick homologue for human C-type natriuretic peptide (CNP), in TGF-β1 induced chondrogenic differentiation of chicken bone marrow-derived mesenchymal stem cells (MSCs). Chondrogenic differentiation of MSCs in pellet cultures was induced by TGF-β1. Chondrogenic differentiation and glycosaminoglycan synthesis were analyzed on the basis of basic histology, collagen type II expression, and Alcian blue staining. Antibodies against CNP and NPR-B were used to block their function during these processes. Results revealed that expression of CNP-3 and NPR-B in MSCs were regulated by TGF-β1 in monolayer cultures at mRNA level. In pellet cultures of MSCs, TGF-β1 successfully induced chondrogenic differentiation and glycosaminoglycan synthesis. Addition of CNP into the TGF-β1 supplemented chondrogenic differentiation medium further induced the glycosaminoglycan synthesis and hypertrophy of differentiated chondrocytes in these pellets. Pellets induced with TGF-β1 and treated with antibodies against CNP and NPR-B, did show collagen type II expression, however, Alcian blue staining showing glycosaminoglycan synthesis was significantly suppressed. In conclusion, CNP-3/NPR-B signaling may strongly be involved in synthesis of glycosaminoglycans of the chondrogenic matrix and hypertrophy of differentiated chondrocytes during TGF-β1 induced chondrogenic differentiation of MSCs.

Effect of Sulfite Treatment on Erythrocyte Deformability in Young and Aged Rats

It is known that aging is associated with marked effects on integrity and function of cell membrane. These effects may also be exacerbated by exogenous chemicals, e.g. sulfite. Thus, the aim of this paper is to examine the influence of sulfite on hemorheological and related hematological parameters in rats of various ages. In this study, male Wistar rats at the age of 3 and 18 months were used and the following parameters were evaluated: Mean Cell Volume (MCV), Mean Corpuscular Hemoglobin Concentration (MCHC), Red blood Cell (RBC) deformability and aggregation. The results show that aging is associated with a decrease in RBC deformability and MCHC, an increase in MCV. Sulfite administration significantly increased RBC deformability in both young and aged rats. Although MCHC was decreased in young rats, it was increased in aged rats in response to sulfite exposure. Additionally, sulfite induced a decrement in MCV of aged rats. Neither aging nor sulfite treatment caused significant alterations in RBC aggregation parameters in all experimental groups. In conclusion, these findings suggest that RBC deformability impairs with age and sulfite has ameliorating effects on RBC deformability in both young and aged rats.

Investigation of Efficacy of Mitomycin-C, Sodium Hyaluronate and Human Amniotic Fluid in Preventing Epidural Fibrosis and Adhesion Using a Rat Laminectomy Model

Study Design A retrospective study. Purpose The aim of this study was to evalute the effects of mitomycin-C, sodium hyaluronate and human amniotic fluid on preventing spinal epidural fibrosis. Overview of Literature The role of scar tissue in pain formation is not exactly known, but it is reported that scar tissue causes adhesions between anatomic structures. Intensive fibrotic tissue compresses on anatomic structures and increases the sensitivity of the nerve root for recurrent herniation and lateral spinal stenosis via limiting movements of the root. Also, neuronal atrophy and axonal degeneration occur under scar tissue. Methods The study design included 4 groups of rats: group 1 was the control group, groups 2, 3, and 4 receieved antifibrotic agents, mitomycin-C (group 2), sodium hyaluronate (group 3), and human amniotic fluid (group 4). Midline incision for all animals were done on L5 for total laminectomy. Four weeks after the surgery, the rats were sacrificed and specimens were stained with hematoxylin-eosin and photos of the slides were taken for quantitive assesment of the scar tissue. Results There was no significant scar tissue in the experimental animals of groups 2, 3, and 4. It was found that there was no significant difference between drug groups, but there was a statistically significant difference between the drug groups and the control group. Conclusions This experimental study shows that implantation of mitomycin-C, sodium hyaluronate and human amniotic fluid reduces epidural fibrosis and adhesions after spinal laminectomy in rat models. Further studies in humans are needed to determine the complications of the agents researched.

Hypertension alters phosphorylation of VASP in brain endothelial cells

Hypertension impairs cerebral vascular function. Vasodilator-stimulated phosphoprotein (VASP) mediates active reorganization of the cytoskeleton via membrane ruffling, aggregation and tethering of actin filaments. VASP regulation of endothelial barrier function has been demonstrated by studies using VASP−/− animals under conditions associated with tissue hypoxia. We hypothesize that hypertension regulates VASP expression and/or phosphorylation in endothelial cells, thereby contributing to dysfunction in the cerebral vasculature. Because exercise has direct and indirect salutary effects on vascular systems that have been damaged by hypertension, we also investigated the effect of exercise on maintenance of VASP expression and/or phosphorylation. We used immunohistochemistry, Western blotting and immunocytochemistry to examine the effect of hypertension on VASP expression and phosphorylation in brain endothelial cells in normotensive [Wistar–Kyoto (WKY)] and spontaneously hypertensive (SH) rats under normal and exercise conditions. In addition, we analyzed VASP regulation in normoxia- and hypoxia-induced endothelial cells. Brain endothelial cells exhibited significantly lower VASP immunoreactivity and phosphorylation at the Ser157 residue in SHR versus WKY rats. Exercise reversed hypertension-induced alterations in VASP phosphorylation. Western blotting and immunocytochemistry indicated reduction in VASP phosphorylation in hypoxic versus normoxic endothelial cells. These results suggest that diminished VASP expression and/or Ser157 phosphorylation mediates endothelial changes associated with hypertension and exercise may normalize these changes, at least in part, by restoring VASP phosphorylation.

Ceruloplasmin, Copper, Selenium, Iron, Zinc, and Manganese Levels in Normal and Sulfite Oxidase Deficient Rat Plasma: Effects of Sulfite Exposure

A noticeable effect of sulfite treatment was observed on the plasma ceruloplasmin ferroxidase activity of rats with normal sulfite oxidase activity when compared to normal controls. The plasma levels of selenium, iron, and zinc were unaffected by sulfite in normal and sulfite oxidase (SOX)-deficient rats. While plasma level of Mn was decreasing, plasma Cu level increased in SOX-deficient rats. Treating SOX-deficient groups with sulfite did not alter plasma level of Mn but made plasma level of Cu back to its normal level. This is the first evidence that Cu and Mn status were affected in experimental sulfite oxidase deficiency induced by low molybdenum diet with tungsten addition deserving further research to determine the underlying mechanisms of these observations in experimental sulfite oxidase deficiency.

Expression of vascular endothelial growth factor and transforming growth factor alpha in rat testis during chronic renal failure

INTRODUCTION Vascular endothelial growth factor (VEGF) is known to influence testis function. Transforming growth factor alpha (TGF-α) is expressed in the postnatal testis, and has been demonstrated to stimulate testis development. Systemic diseases such as chronic renal failure (CRF) interfere with hypothalamic-pituitary-gonadal axis, which may cause defective steroidogenesis and gonadal functions. The aim of this study was to investigate the expression and localization of VEGF and TGF-α in testicular tissues of experimental CRF model. MATERIAL AND METHODS Experimental CRF was induced in rats by the resection of more than 85% of renal mass. The expression of VEGF and TGF-α in testicular tissues were assessed by immunohistochemistry on paraffin sections of control, CRF-nondialysed and CRF-dialysed rats. RESULTS The microscopic evaluation of the testicular structure showed that CRF did not affect testicular histology. Immunohistochemical evaluation showed that VEGF was expressed in the cytoplasm of primary and secondary spermatocyte series as well as the early spermatids. Staining intensity was lower in spermatocytes going through the first meiotic division. TGF-α was expressed in the nuclei of spermatogonia and primary spermatocytes with stronger staining intensity in spermatogonia. The intensity of VEGF staining was similar in control and experimental animals, however, TGF-α expression was lower in the CRF group. CONCLUSIONS The continuous expression of VEGF in spermatocytes and spermatids suggests that the applied model of CRF does not directly disrupt morphology of seminiferous epithelium, thus also spermiogenesis. However, difference between control rats and CRF group in TGF-α immunopositivity, which was localised in spermatogonial mitosis step, may suggest the interference of CRF with early stages of spermatogenesis.