vasoactive-intestinal-peptide and Infarction--Middle-Cerebral-Artery

To investigate the effects of vasoactive intestinal peptide on the blood brain barrier function after focal cerebral ischemia in rats.. Rats were intracerebroventricular injected with vasoactive intestinal peptide after a two hours middle cerebral artery occlusion. Functional outcome was studied with the neurological severity score. The brain edema and the infarction were evaluated via histology. The blood brain barrier permeability was assessed using Evans Blue dye injection method. We also measure the apoptosis of brain microvascular endothelial cells and brain levels of B-cell leukemia-2 protein by immunohistochemical analysis and western blotting, respectively.. In contrast to the cases treated with vehicle at 72 h after middle cerebral artery occlusion, the treatment with vasoactive intestinal peptide significantly (P < 0.05) reduced the neurological severity score, the brain edema and infarct volume. The Evans Blue leakage and brain water content were obviously reduced (P < 0.05) in vasoactive intestinal peptide-treated rats compared with those of control rats at 72 and 96 h after stroke. In addition, vasoactive intestinal peptide decreased the numbers of terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling positive endothelial cells and increased the protein levels of B-cell leukemia-2 in the ischemic hemisphere at 72 h after ischemia.. Our data suggest that treatment with vasoactive intestinal peptide ameliorates the blood brain barrier function, contributing to reduce in brain damage both morphologically and functionally in the ischemic rat. This amelioration may be associated with attenuation in apoptosis of brain microvascular endothelial cells by increased B-cell leukemia-2 expression.

Topics: Animals; Blood-Brain Barrier; Brain Edema; Brain Ischemia; Endothelial Cells; Humans; Infarction, Middle Cerebral Artery; Rats; Rats, Sprague-Dawley; Vasoactive Intestinal Peptide

Background Shengui Sansheng Pulvis (SSP) has about 300 years history used for stroke treatment, and evidences suggest it has beneficial effects on neuro-angiogenesis and cerebral energy metabolic amelioration post-stroke. However, its protective action and mechanisms on blood-brain barrier (BBB) is still unknown. Purpose Based on multiple neuroprotective properties of vasoactive intestinal peptide (VIP) in neurological disorders, we investigate if SSP maintaining BBB integrity is associated with VIP pathway in rat permanent middle cerebral artery occlusion (MCAo) model. Methods Three doses of SSP extraction were administered orally. Evaluations of motor and balance abilities and detection of brain edema were performed, and BBB permeability were assessed by Evans blue (EB) staining. Primary brain microvascular endothelial cells (BMECs) were subjected to oxygen-glucose deprivation, and incubated with high dose SSP drug-containing serum and VIP-antagonist respectively. Transendothelial electrical resistance (TEER) assay and Tetramethylrhodamine isothiocyanate (TRITC)-dextran (4.4 kDa) and fluorescein isothiocyanate (FITC)-dextran (70 kDa) were used to evaluate the features of paracellular junction. Western blot detected the expressions of Claudin-5, ZO-1, Occludin and VE-cadherin, matrix metalloproteinase (MMP) 2/9 and VIP receptors 1/2, and immunofluorescence staining tested VIP and Claudin-5 expressions. Results Our results show that SSP significantly reduces EB infiltration in dose-dependent manner in vivo and attenuates TRITC- dextran and FITC-dextran diffusion in vitro, and strengthens endothelial junctional complexes as represented by decreasing Claudin-5, ZO-1, Occludin and VE-cadherin degradations and MMP 2/9 expression, as well as promoting TEER in BMECs after ischemia. Moreover, it suggests that SSP notably enhances VIP and its receptors 1/2 expressions. VIP-antagonist exacerbates paracellular barrier of BMECs, while the result is reversed after incubation with high dose SSP drug-containing serum. Additionally, SSP also improve brain edema and motor and balance abilities after ischemic stroke. Conclusions we firstly demonstrate that the ameliorated efficacy of SSP on BBB permeability is related to the enhancements of VIP and its receptors, suggesting SSP might be an effective therapeutic agent on maintaining BBB integrity post-stroke.

Topics: Animals; Blood-Brain Barrier; Brain Ischemia; Claudin-5; Drugs, Chinese Herbal; Endothelial Cells; Endothelium, Vascular; Infarction, Middle Cerebral Artery; Male; Permeability; Rats, Inbred Strains; Receptors, Vasoactive Intestinal Peptide, Type II; Receptors, Vasoactive Intestinal Polypeptide, Type I; Stroke; Vasoactive Intestinal Peptide

Reduced blood flow to the brain induces cerebral ischaemia, potentially causing central injury and peripheral complications including gastrointestinal (GI) dysfunction. The pathophysiology behind GI symptoms is suspected to be neuropathy in the enteric nervous system (ENS), which is essential in regulating GI function. This study investigates if enteric neuropathy occurs after cerebral ischaemia, by analysing neuronal survival and relative numbers of vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (nNOS) expressing neurons in mouse ileum after three types of cerebral ischaemia. Focal cerebral ischaemia, modelled by permanent middle cerebral artery occlusion (pMCAO) and global cerebral ischaemia, modelled with either transient occlusion of both common carotid arteries followed by reperfusion (GCIR) or chronic cerebral hypoperfusion (CCH) was performed on C56BL/6 mice. Sham-operated mice for each ischaemia model served as control. Ileum was collected after 1-17 weeks, depending on model, and analysed using morphometry and immunocytochemistry. For each group, intestinal mucosa and muscle layer thicknesses, neuronal numbers and relative proportions of neurons immunoreactive (IR) for nNOS or VIP were estimated. No alterations in mucosa or muscle layer thicknesses were noted in any of the groups. Loss of myenteric neurons and an increased number of VIP-IR submucous neurons were found in mouse ileum 7 days after pMCAO. None of the global ischaemia models showed any alterations in neuronal survival or relative numbers of VIP- and nNOS-IR neurons. We conclude that focal cerebral ischaemia and global cerebral ischaemia influence enteric neuronal survival differently. This is suggested to reflect differences in peripheral neuro-immune responses.

Topics: Animals; Brain Ischemia; Carotid Stenosis; Cell Death; Cerebrovascular Circulation; Disease Models, Animal; Ileum; Infarction, Middle Cerebral Artery; Male; Mice, Inbred C57BL; Myenteric Plexus; Neurons; Nitric Oxide Synthase Type I; Time Factors; Up-Regulation; Vasoactive Intestinal Peptide

The aim of this study was to investigate the effects of vasoactive intestinal peptide (VIP) on neurogenesis and neurological function after cerebral ischemia. Rats were intracerebroventricular administered with VIP after a 2h middle cerebral artery occlusion (MCAO) and sacrificed at 7, 14 and 28 days after MCAO. Functional outcome was studied with the modified neurological severity score. The infarct volume was evaluated via histology. Neurogenesis, angiogenesis and the protein expression of vascular endothelial growth factor (VEGF) were measured by immunohistochemistry and Western blotting analysis, respectively. The treatment with VIP significantly reduced the neurological severity score and the infarc volume, and increased the numbers of bromodeoxyuridine (BrdU) immunoreactive cells and doublecortin immunoreactive area in the subventricular zone (SVZ) at 7, 14 and 28 days after ischemia. The cerebral protein levels of VEGF and VEGF expression in the SVZ were also enhanced in VIP-treated rats at 7 days after stroke. VIP treatment obviously increased the number of BrdU positive endothelial cells in the SVZ and density of cerebral microvessels in the ischemic boundary at 28 days after ischemia. Our study suggests that in the ischemic rat brain VIP reduces brain damage and promotes neurogenesis by increasing VEGF. VIP-enhanced neurogenesis is associated with angiogenesis. These changes may contribute to improvement in functional outcome.

Topics: Animals; Antigens, CD34; Bromodeoxyuridine; Cell Count; Disease Models, Animal; Doublecortin Domain Proteins; Doublecortin Protein; Endothelial Cells; Infarction, Middle Cerebral Artery; Male; Microtubule-Associated Proteins; Nervous System Diseases; Neurogenesis; Neuropeptides; Rats; Rats, Sprague-Dawley; Time Factors; Vascular Endothelial Growth Factor A; Vasoactive Intestinal Peptide

VPAC2 receptor is a potential target for the treatment of type 2 diabetes and may also convey neuroprotective effects. The aim of this study was to determine the potential efficacy of the VPAC2 receptor agonist Bay 55-9837 against stroke in type-2 diabetic Goto-Kakizaki (GK) rats. GK rats were treated intravenously once daily for 7 days with 0.25 or 0.025 nmol/kg Bay 55-9837 or vehicle before inducing stroke by transient middle cerebral artery occlusion. Treatments were then continued for 7 further days. The glycemic effects of Bay 55-9837 were assessed by measuring fasting blood glucose and oral glucose tolerance. The severity of stroke was measured by assessing ischemic volume. The results show that Bay 55-9837 is not effective in lowering fasting glycemia and does not facilitate glucose disposal. The highest dose of Bay 55-9837 (0.25 nmol/kg) led to increased mortality and brain hemorrhage when compared to control. The lower dose of Bay 55-9837 (0.025 nmol/kg) did not increase mortality rate but caused a threefold increase of the ischemic lesion size with signs of brain hemorrhages as compared to control. In conclusion, Bay 55-9837 did not show antidiabetic or antistroke efficacy in the type 2 diabetic GK rat. Contrarily, Bay 55-9837 treatment led to increased mortality and worsening of the severity of stroke.

Topics: Animals; Blood Glucose; Cell Count; Diabetes Mellitus, Type 2; Disease Progression; Glucose Tolerance Test; Immunohistochemistry; Infarction, Middle Cerebral Artery; Intracranial Hemorrhages; Male; Middle Cerebral Artery; Neurons; Peptide Fragments; Rats; Receptors, Vasoactive Intestinal Peptide, Type II; Stroke; Vasoactive Intestinal Peptide

To explore the neuroprotective action of vasoactive intestinal peptide (VIP) on ischemia and reperfusion in the rat.. VIP was given via intracerebroventriclar injection after a 2 hour transient middle cerebral artery occlusion using filament model. The infarct volume was investigated with TTC stain. Apoptosis in the ischemic boundary zone were evaluated with TUNEL stain. Western blotting were used to analyze the iNOS protein expression as well.. After VIP injection, the relative infarct volume of rats was significantly reduced by approximately 28% campared to that of the control groups at 1 day (P < 0.05). The number of TUNEL positive cells was significantly decreased in the ischemic boundary zone, and then the expression of iNOS was remarkablely decreased as well (P < 0.05).. VIP has a neuroprotective effect on cerebral ischemia and reperfusion. The mechanism seems to involve decreasing the apoptosis and down-regulating the iNOS expression.

Topics: Animals; Apoptosis; Blotting, Western; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Male; Neuroprotective Agents; Nitric Oxide Synthase Type II; Rats; Rats, Sprague-Dawley; Vasoactive Intestinal Peptide

Vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase-activating peptide (PACAP), are members of a VIP/secretin/glucagon family. These peptides were demonstrated to possess the neuroprotective properties. However, these peptides are not suited to be developed as a medicine for brain ischemia because of their susceptibilities to endopeptidases.. We examined the effects of IK 312548 (IK), VIP derivative, and Ac-PACAP, PACAP derivative, on the 10 min two-vessel occlusion (2 VO) model in C 57 BL/6 N mice lacking a part of the posterior communicating artery, and the 30 min middle cerebral artery occlusion (MCAO) model in ICR mice. A 10 ml x kg(-1) dose of each derivative (final concentration; 1 fmol x kg(-1) and 100 pmol x kg(-1)) was injected intraperitoneally (i.p.) to each animal just after the preparation of brain ischemia.. In 2 VO experiments, the number of neuronal cells in hippocampus was significantly reduced. However IK and Ac-PACAP treatments inhibited such reductions of neuronal cells in a dose-dependent manner. Particularly, between 1 pmol x kg(-1) and 100 pmol x kg(-) IK, and also between 10 fmol x kg(-1) and 1 pmol x kg(-1) Ac-PACAP significantly protected neuronal cell loss. In MCAO experiments, more than 60% of hemisphere was damaged. By treatment of IK (1-100 pmol x kg(-1)) and Ac-PACAP (1 fmol-1 pmol x kg(-1)), the range of brain damage decreased in a dose-dependent manner.. Ac-PACAP and IK after the brain ischemia could pass the blood-brain barrier and protect brain cell damage.

Topics: Animals; Brain Ischemia; Cerebrovascular Circulation; Hippocampus; Infarction, Middle Cerebral Artery; Injections, Intraperitoneal; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Nerve Growth Factors; Neuropeptides; Neuroprotective Agents; Neurotransmitter Agents; Pituitary Adenylate Cyclase-Activating Polypeptide; Vasoactive Intestinal Peptide

Pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) belong to the same peptide family, and both neuropeptides have been shown to exert in vitro and in vivo neurotrophic and neuroprotective effects. The aim of the present study was to investigate and compare the protective effects of PACAP and VIP in permanent focal cerebral ischemia in rats. The effect on the progression of the cerebral infarct was also studied.. Male rats were injected 450 pmol PACAP or VIP dissolved in physiological saline intracerebroventricularly, preceding the occlusion of the middle cerebral artery. Control animals received vehicle treatment. Permanent focal ischemia was induced by the intraluminal filament occlusion of the middle cerebral artery. Animals were sacrificed 12 or 24 hours after the onset of ischemia, and infarcted brain areas were determined by staining bran sections with triphenyl-tetrazolium chloride.. Twelve hours after ischemia, the infarcted brain volume resulted to be 14.8% in the control group, 15.3% in the VIP-treated group and 5.8% in the PACAP-treated animals. Twenty-four hours after middle cerebral artery occlusion, the infarcted brain volumes were 21.5%, 20.7% and 14.3% in the control, VIP and PACAP-treated animals, respectively.. Our results provide further evidence for the neuroprotective effects of PACAP38 as given in form of a preischemic bolus. It slows down the progression of the evolution of the infarct and reduces the final infarct size. In contrast, a related peptide, VIP, does not have neuroprotective effects under the same experimental conditions.

Topics: Animals; Body Temperature; Brain Ischemia; Infarction, Middle Cerebral Artery; Male; Neuropeptides; Neuroprotective Agents; Pituitary Adenylate Cyclase-Activating Polypeptide; Rats; Rats, Wistar; Vasoactive Intestinal Peptide