Two-dimensional maximum-intensity-projections of

<p><b>TOF-MRA of rat brain.</b> Coronal images of rat brains were screened in 3 mm slices. The rat shown in A, B was immunized with the α₁-AR peptide, the rat shown in C, D obtained vehicle as control. Injections were performed monthly. Angiographs of the same animal were taken at the beginning of the treatment (A, C) and eight months later (B, D). Light contrasts correlate with vascular blood flow. Eight months of treatment with the α₁-AR peptide led to apparent attenuations of blood flow (B, right part of brain section) compared to the initial situation (A). Control injections did not result in comparable defects in the same time frame (D versus C).</p

Comparison of relative vascular areas.

<p>Cohorts of rats were treated either with intravenous injections of α₁-adrenoceptor antibody (AB) or with subcutaneous injections with α₁-adrenoceptor peptide (PEP). Control animals received unspecific control IgG (C-AB) or albumin (C-PEP). Applications of substances were repeated monthly. The time span between TOF-MRA measurement 1 and measurement 2 was eight months. Relative vascular areas were determined by grayscale analysis of two-dimensional TOF-MRA maximum-intensity-projections. Values are given as means ± standard error of the mean. The number of animals of each group is given in brackets.</p>*<p>significantly different to measurement 1 (p<0.05).</p

Box plot of relative brain vascular blood flow.

<p>Vascular area was calculated from two-dimensional section of angiographs of rat brains by grayscale analysis as described in the methods section. Relative vascular circulation of the individual animal is expressed as ratios of vascular areas from the last and the first TOF-MRA. Time between measurements was eight months. Ratios <1 indicate attenuated vascular blood flow. Data are given of animals treated with intravenous injections of the antibody to the α₁-AR (AB; n = 9), their controls (C-AB); n = 10), and rats injected subcutaneously with the α₁-AR peptide (PEP; n = 10) and the respective controls (C-PEP; n = 10). Asterisk indicates statistically significant differences with p<0.05.</p

Analysis of rat sera for the presence of antibodies to the α₁-AR.

<p>Antibodies were detected by ELISA. (PEP) rats immunized with the α₁-AR peptide, (C-PEP) controls treated with vehicle. Blood samples were taken about one month before the final TOF-MRA. The obtained sera were analyzed at a 1∶50 dilution.</p

Anatomical images and TOF-MRA of the rat brain.

<p>Maximum-intensity-projections (MIP) of the TOF-MRA image data are shown for a coronal view (B) and axial view (E) together with corresponding 2-dimensional anatomical T₂-weighted image slices (A, D). C) sagittal MIP view. F) double-oblique MIP view from the left posterior perspective (shown at a smaller scale).</p

Black and white threshold images.

<p>Two-dimensional sections of maximum-intensity-projections (MIP) of TOF-MRA images were processed as described in Materials and Methods. The black and white images were generated using the median plus two standard deviations as threshold value. White areas correspond approximately to the area of vessels with blood flow. Exemplarily shown is one animal treated with intravenous injections of the α₁-AR antibody (A, B) and one control animal (C, D) at measurement 1 (A, C) and at measurement 2 eight months later (B, D). The reduction of the white areas in B compared to A is evident.</p

TOF-MRA of rat brain.

<p>Three-dimensional coronal views of the frontal brain segment. The rat shown is as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041602#pone-0041602-g003" target="_blank">Figure 3</a> which was immunized with the α₁-AR peptide. Angiographs of the same animal were taken at the beginning of the treatment (A, C) and eight months later (B, C). C, D show the same brain segment as in A, C but vertically rotated by 45°. The defects in blood flow in the right part of the brain as displayed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041602#pone-0041602-g003" target="_blank">Figure 3</a> are obvious (B, D) compared to the situation eight months before (A, C).</p