31 research outputs found
Mercury content in each region of brain based on duration of methylmercury exposure.
<p>Mercury content in each region of brain based on duration of methylmercury exposure.</p
Time course of experiments and sample preparation.
<p>(a) Six-week-old male Wistar rats were divided into five groups as follows: control, 1-, 2-, 3-, and 4-week MeHg exposure groups (n = six per group). Rats were administered water with or without 20-ppm MeHg from 6 weeks of age. Rabbit anti-VEGF neutralizing antibody was intravenously administered twice at 6 and 8 weeks of age (arrow) at doses of 10 and 20 μg (42–44 and 56–64 μg/kg), respectively, for the low-dose anti-VEGF (L) group or 20 and 100 μg (81–87 and 301–332 μg/kg), respectively, for the high-dose anti-VEGF (H) group. Brain tissues were harvested at 10 weeks of age. (b) Brains were separated into the cerebellum and cerebrum; the cerebrum was further separated into frontal, central, and occipital regions.</p
COMP-Ang1 protein localization in the tPA-4h group visualized with a confocal laser microscope.
<p>From left to right: markers of cells that make up the blood brain barrier (a, e, i; red), neuronal cell (m; red), COMP-Ang1 protein (b, f, j, n; green), DAPI stain (c, g, k, o; blue), and a merged image (d, h, l, p). Immunostaining with an anti-FLAG antibody was performed on COMP-Ang1 proteins in order to differentiate them from endogenous Ang1. RECA1 is an endothelial cell marker protein; PDGFRβ is a pericyte marker; GFAP is an astrocyte marker; and MAP2 is a neuronal cell marker. RECA1, rat endothelial cell antigen; PDGFRβ, platelet-derived growth factor receptor; GFAP, glial fibrillary acidic protein; Ang1, angiopoietin-1. The scale bars are 10 µm.</p
Effects of COMP-Ang1 protein administration on the tPA-4h group.
<p>These panels show the amount of cerebral hemorrhage (A), cerebral edema volume (B), cerebral infarct volume (C), and the prognosis with a 6-point neurological scale score (D) 24 h after ischemia. A-C were performed on the COMP-Ang1 group (N = 5) and the COMP group (N = 5). D was performed on the COMP-Ang1 group (N = 11) and the COMP group (N = 9). Cerebral edema and infarct volumes are expressed as proportions on the ischemic side of the cerebral hemisphere. The amount of cerebral hemorrhage is expressed as hemoglobin concentration in a whole cerebral homogenate. COMP; cartilage oligomeric protein, COMP-Ang1; cartilage oligomeric protein-angiopoietin-1.</p
Changes in Ang1-positive vessels due to focal cerebral ischemia.
<p>(A) Immunohistochemical staining with an anti-Ang1 antibody. Representative findings are shown of the peri-infarct and infarct areas of the control, tPA-1h, tPA-4h, and PMCAO groups. High magnification (1,000×) is shown in the upper right of the low magnification (200×) photograph. Ang1-positive vessels were shown by asterisk. tPA, tissue plasminogen activator; PMCAO, permanent middle cerebral artery occlusion; Ang1, angiopoietin-1. The black scale bar is 10 µm, and the red scale bar is 100 µm. (B) Mean number of Ang1-positive vessels. Three locations were chosen randomly in the control cerebral cortex and in each infarct area and peri-infarct area. The figures are the mean number of Ang1-positive vessels from 3 random fields of view of an optical microscope at 200× magnification. Each group N = 5.</p
Hind-limb crossing signs after 4-week exposure to methylmercury (MeHg) with or without intravenous administration of anti-vascular endothelial growth factor (VEGF) neutralizing antibody.
<p>Neuronal impairment was evaluated by assessing the presence of hind-limb crossing signs after 4 weeks of MeHg exposure with or without anti-VEGF antibody treatment. Neuronal impairment was evaluated according to the following scale: (+++) limbs crossed each other; (++), limbs nearly crossed; (+) limbs did not cross and limb flexion was observed; and (-), limbs moved freely and were typically splayed outward; n = six to eight per group. Control, MeHg exposure without treatment; anti-VEGF (L), low dose anti-VEGF antibody group; anti-VEGF (H), high dose anti-VEGF group.</p
Incidence of hind-limb crossing signs after methylmercury exposure.
<p>Hind-limb crossing signs at 10 weeks of age are shown. Rats were held by the tail, and the posture of both hind-limbs was observed. This phenomenon was graded according to the following scale: (+++), limbs crossed each other; (++), limbs nearly crossed; (+), limbs did not cross and limb flexion was observed; and (-), limbs moved freely and were typically splayed outward. All the rat in control group and the rat in the 1- and 2-week MeHg exposure groups did not show a hind-limb crossing sign; therefore, the results for three groups are integrated into one bar (n = five or six per group).</p
Time course of changes in body weight.
<p>Body weight was measured 2 times per week and plotted. Each line in the same color shown in the explanatory notes represents a single rat exposed to mercury in the same period. Body weight increased from 6 weeks to 10 weeks in the control group (green) and the 1- or 2-week exposure groups (orange and purple lines, respectively). However, body weight decreased following 2 or 3 weeks of exposure to methylmercury (after 8 weeks: black line, after 9 weeks: blue line).</p
Expression of endothelial cell markers and IgG extravasation in the cerebellum of rats exposed to methylmercury.
<p>(a) Rat cerebellum sections from control and 4-week exposure groups (upper and lower panels, respectively) were stained using an antibody against rat endothelial cell antigen-1 (RECA-1). Low and high (left and right panel, respectively) magnification images are shown. Scale bars, 100 and 10 μm (left and right panel, respectively). (b) Rat cerebellum sections from control and 4-week exposure groups (upper and lower panels, respectively) were stained using an antibody against rat IgG. Vascular hyperpermeability was evaluated by immunostaining of intrinsic IgG outside of vessels in control and 4-week exposure groups. Arrows indicate IgG extravasation in the 4-week MeHg exposure group. No IgG staining outside of vessels was detected in the control group. Scale bar, 25 μm. All experiments were performed in triplicate.</p
Vascular endothelial growth factor (VEGF) expression associated with methylmercury exposure.
<p>(a) Immunohistochemical staining was performed using rabbit anti-VEGF antibody to detect VEGF expression in the frontal and occipital regions and cerebellum of rats in the control and 4-week MeHg exposure groups (left and right panels, respectively). Scale bar, 50 μm. (b) Representative images of double immunohistochemical staining sections of cerebellum in the 4-week MeHg exposure group. VEGF (red) and rat endothelial cell antigen-1 (RECA-1, a marker of endothelial cells, green) positive cells are shown. Scale bar, 20 μm. (c) Double immunohistochemical staining for VEGF (red) and glial fibrillary acidic protein (GFAP, a marker of astrocytes, green). Scale bar, 30 μm. All experiments were performed in triplicate.</p