Fig 2: (A) Individual data points and means (black bars) of mean gray value of EDNRA in immunofluorescence after observation period of 12 weeks. Both CTL and HT groups showed similar levels of fluorescence intensity as reflection of EDRNA abundance. Despite tendency to higher levels after HT induction, none of the groups significantly differed. Therefore, EDNRA abundance seemed not to be higher after HT induction, neither in WT rats nor EDNRA rats. (B–E) One exemplary ring segment of BA of each group showing EDNRA immunoreactivity (red) and nuclei (blue): (B): WT_CTL; (C): EDNRA_CTL; (D): WT + HT; and (E): EDNRA + HT.

Fig 3: Vascular anomalies (ectasia and aneurysm) were observed only in HT-induced rats (p < 0.001) after observation period of 12 weeks. WT_CTL (N = 0/14) and EDNRA_CTL (N = 0/14) did not develop vascular anomalies. There was no difference of frequency of anomalies between WT + HT (N = 3/10) and EDNRA + HT (N = 8/15).

Fig 4: Exemplary results of genotyping of six rats’ DNA. Heterozygous EDNRA rats showed wild-type bands and mutant bands (1504 bp and 1092 bp) as verification of deletion. Marker on left side, kb = kilobase pairs.

Fig 5: Light microscopy (magnification: 50×) of the brain of EDNRA + HT rat after observation period of 12 weeks. The basilar artery (not pictured) branches into both posterior cerebral arteries [32]. A saccular aneurysm with detritus evolved at the right posterior communicating artery. (A) Original picture. (B) Marked left and right posterior communicating artery with a saccular aneurysm (hatching).