CT perfusion imaging of cerebral microcirculatory changes following subarachnoid hemorrhage in rabbits: Specific role of endothelin-1 receptor antagonist

The Role of ET-1 in Early Cerebral Microcirculation Changes after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH), especially aneurysmal subarachnoid hemorrhage, is a serious cerebrovascular disease with high mortality and morbidity. However, there is no effective treatment in clinics. In recent years, more and more studies have shown that early brain injury (EBI) may be an important reason for poor prognosis of SAH. Explore the mechanism of early brain injury after subarachnoid hemorrhage (SAH). In this study, 20 male New Zealand white rabbits were selected and divided into the experimental group and sham operation group, with 10 rabbits in each group. The neurobehavioral scores, food intake, and cerebral perfusion parameters, cerebral blood volume (CBV), cerebral blood flow velocity (CBF), ET-1, IL-1, and IL-6, in rabbit plasma were compared. The food intake scores and neurological dysfunction scores of the experimental group at 1 h, 6 h, 24 h, and 72 h after modeling were higher than those of the sham operation group, which had a statistical significance (P < 0.05). The dysfunction scores all showed a gradual decrease; the CBV and CBF values of the experimental group at 1 h, 6 h, 24 h, and 72 h after modeling were all lower than those of the sham operation group, which had a statistical significance (P < 0.05), and the MTT values were all higher than that of the sham operation group, which had a statistical significance (P < 0.05). The TTP values of rats in the experimental group were higher than those in the sham operation group at 6 h, 24 h, and 72 h after modeling (P < 0.05), the experimental group was in the modeling. The levels of serum ET-1, IL-1, and IL-6 at 1 h, 6 h, 24 h, and 72 h were higher than those in the sham operation group, which had a statistical significance (P < 0.05). New Zealand white rabbits can have brain perfusion volume disorder, inflammatory reaction, and cerebral vasospasm in the early stage after SAH, and brain injury can appear in the early stage.

Cerebral venous circulation changes caused by aneurysmal subarachnoid hemorrhage

BACKGROUND

The aneurysmal subarachnoid hemorrhage (aSAH) is an acute severe hemorrhagic stroke with high morbidity and mortality with poor prognosis.

OBJECTIVE

This study aims to analyze the changes of cerebral venous circulation in patients with aneurysmal subarachnoid hemorrhage by digital subtraction angiography (DSA).

MATERIALS AND METHODS

Totally, 57 patients with aSAH, 48 patients with unruptured aneurysms, and 45 patients without aneurysms (control group) were enrolled. The microvascular cerebral circulation time (mCCT), venous cerebral circulation time (vCCT), cerebral arterioles and cortical veins were analyzed by DSA.

RESULTS

There were changes of cerebral microvessels and cortical veins in patients with aSAH. The mCCT (6.15±1.37 s) and vCCT (2.79±0.34 s) of aSAH patients significantly increased compared with control patients (3.74±0.50 s; 2.64±0.32 s) (P < 0.05). However, the mCCT increased more compared with vCCT in aSAH patients (P < 0.001), while the vCCT increased more compared with mCCT in severe aSAH cases (P < 0.01). There was no significant difference in mCCT and vCCT between patients with unruptured aneurysms and controls (P = 0.131; P = 0.621).

CONCLUSIONS

The mCCT increases in acute aSAH patients within 72 hours and vCCT increases in severe aSAH cases.

Potential role of poly (ADP-ribose) polymerase in delayed cerebral vasospasm following subarachnoid hemorrhage in rats

Poly (ADP-ribose) polymerase (PARP) serves a key role in several neurological disorders, however, the specific role of PARP in delayed cerebral vasospasm (DCVS) following subarachnoid hemorrhage (SAH) remains unclear. The present study was conducted to clarify the possible mechanism of PARP in DCVS with the treatment of 3-aminobenzamide (3-AB), a PARP inhibitor. In the preliminary experiment, an internal carotid artery puncture SAH model, a cisterna magna double injection SAH model and prechiasmatic cistern single injection SAH model were compared with respect to mortality and neurobehavioral test results. The prechiasmatic cistern single injection SAH model was chosen to induce DCVS in the formal experiment. In the formal experiment, a total of 96 Sprague Dawley rats were randomly allocated into the sham group, the SAH group and the SAH+3-AB group and then each group was further subdivided into days 3, 5, 7 and 14 post-SAH subgroups (n=8 for each subgroup). The prechiasmatic cistern single injection SAH model was established to induce DCVS. Neurobehavioral testing and HE staining were conducted to evaluate the degree of cerebral vasospasm. PARP activity was assessed by ELISA and immunohistochemistry. An electrophoretic mobility shift assay was used to detect nuclear factor (NF)-κB DNA-binding activity. The expression of monocyte chemotactic protein 1 (MCP-1) and C-reactive protein (CRP) were measured by western blotting. Cerebral vasospasm occurred following SAH and became most severe on around day 7 post-SAH. NF-κB activity, PARP activity, the expression of MCP-1 and CRP exhibited a similar time course to cerebral vasospasm. Treatment with 3-AB alleviated the degree of cerebral vasospasm. NF-κB activity, PARP activity and the expression of MCP-1 and CRP were also suppressed by 3-AB treatment. In conclusion, PARP may serve an important role in regulating the inflammatory response and ultimately contribute to DCVS. Therefore 3-AB may be a potential therapeutic agent for DCVS.