vasoactive-intestinal-peptide and Subarachnoid-Hemorrhage

Neuroinflammation is implicated in cerebral vasospasm and brain injuries after subarachnoid hemorrhage (SAH). In addition to classical neuroinflammation with increased inflammatory cytokines, a sterile neurogenic inflammation characterized by release of potent vasoactive neuropeptides may be responsible for brain injuries after SAH. Sympathetic discharges from superior cervical ganglion contribute to vasoconstriction of cerebral arteries Thus, we investigated the effects of surgical cervical sympathectomy on the neurogenic inflammatory neuropeptides shortly after SAH induction in a model of SAH in rats.. Male Wistar rats were divided into 4 groups: control; was not touched, saline group; 300 μl of saline was injected into prechiasmatic cistern, SAH+Sham group; 300 μl of autologous blood was injected to induce subarachnoid hemorrhage into prechiasmatic cistern; SAH+Symp group; the left cervical sympathetic branch was surgically removed after the induction of SAH. Levels of neuropeptides CGRP, SP and VIP which are responsible for neurogenic inflammation, in plasma, trigeminal ganglion, brainstem and brain tissue were measured by ELISA. In addition, c-fos expression as a marker of neuronal activation in the trigeminal nucleus caudalis (TNC) was determined by immunohistochemical staining.. SAH significantly increased c-fos expression in the TNC, as well as CGRP, SP and VIP concentrations in plasma and trigeminal ganglion neurons, and also CGRP and SP concentrations in the brainstem. Cervical sympathectomy application significantly reduced the increases in these parameters induced by SAH.. Our findings suggest that cervical sympathectomy treatment may prevent early brain injury by modulating SAH-induced neurogenic inflammatory neuropeptides such as CGRP, SP and VIP, and improve the quality of life in survivors following SAH.

Topics: Animals; Calcitonin Gene-Related Peptide; Encephalitis; Ganglionectomy; Inflammation Mediators; Male; Neuropeptides; Rats, Wistar; Subarachnoid Hemorrhage; Substance P; Sympathetic Nervous System; Trigeminal Ganglion; Trigeminal Nuclei; Vasoactive Intestinal Peptide

A possible involvement of perivascular vasodilatory neuropeptides in subarachnoid haemorrhage (SAH) has been evaluated in man by measuring the levels of calcitonin gene related peptide (CGRP)-, substance P (SP)- and vasoactive intestinal peptide (VIP)-like immunoreactivity (LI) in the cranial venous outflow and in CSF in 34 patients admitted to the hospital after an acute SAH. After operation with aneurysm clipping and nimodipine treatment, blood samples were taken from the external jugular vein (EJV) or cerebrospinal fluid (CSF) and analysed for neuropeptide levels with specific radioimmuno assays (RIA) during the postoperative course. The degree of vasoconstriction in the patients was monitored with Doppler ultrasound recordings bilaterally from the middle cerebral (MCA) and internal carotid arteries (ICA) following the EJV blood sampling every second day. The mean value of all CGRP-LI measurements in EJV during the entire course of SAH (n = 20) revealed a significantly higher level as compared to controls. The highest CGRP-LI levels were found in patients with the highest velocity index values (vasospasm). The relationship Vmean MCA/Vmean ICA was used as an index of vasoconstriction. In patients with MCA aneurysms (n = 10), a significant correlation (r = 0.65, p < 0.05) was found between the vasospasm index and CGRP-LI levels. There were no changes observed in the SP- and VIP-LI levels. Alterations in cerebrovascular tone induced by changing arterial CO2 tension or lowering of blood pressure (ketanserin infusion test) did not alter the levels of the perivascular peptides in the EJV. In addition, CGRP-, SP-, VIP- and neuropeptide Y (NPY)-LI were analysed in CSF in the post-operative course after subarachnoid haemorrhage (SAH) in 14 patients. The CSF VIP-LI was lower in SAH than in control (p < 0.05). The CGRP-LI level was measurable in SAH CSF but not in CSF of controls. In individual patients with marked vasoconstriction increased levels of CGRP-LI (up to 14 pmol/L) and NPY-LI (up to 232 pmol/L) were observed. The results of this study are in support of our hypothesis that there is an involvement of the sensory peptide CGRP in a dynamic reflex aimed at counterbalancing vasoconstriction in SAH.

Topics: Adult; Aged; Aneurysm, Ruptured; Blood-Brain Barrier; Brain; Calcitonin Gene-Related Peptide; Female; Homeostasis; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Jugular Veins; Male; Middle Aged; Postoperative Complications; Subarachnoid Hemorrhage; Substance P; Ultrasonography, Doppler, Transcranial; Vasoactive Intestinal Peptide; Vasoconstriction; Vasodilation

INTRODUCTION--Cerebral blood vessels are innervated by sympathetic nerve fibres storing neuropeptide Y (NPY), parasympathetic nerves storing acetylcholine, vasoactive intestinal peptide (VIP) and sensory afferent fibres containing calcitonin gene-related peptide (CGRP), substance P (SP) and neurokinin A. In experimental studies on subarachnoid haemorrhage (SAH) there are indications that perivascular peptides are involved. In the present study we have in man measured the levels of NPY, VIP, SP and CGRP in brain vessels of patients that have suffered a fatal SAH and compared this with the levels encountered in subjects that died of an extracerebral cause. MATERIAL AND METHODS--Vessels from patients who have died from SAH or nonSAH were obtained during autopsy performed within 24 hrs after death. The peptides were extracted and fractionated with reversed phase liquid chromatography (HPLC). The levels of NPY, VIP, SP, and CGRP were measured with radioimmunoassay. Vasomotor responses of human cerebral arteries were performed using a sensitive in vitro system. RESULTS--Human cerebral vessels contained NPY, VIP, CGRP and SP which eluted at the same positions as the authentic peptides. The level of CGRP was significantly lower (p < 0.01) in arteries removed from SAH patients as compared to control subjects. The level of SP was not changed, if anything it tended to be increased after SAH. The levels of NPY and VIP were not significantly altered after SAH. In isolated brain vessels alpha-CGRP was a potent vasodilator of arteries precontracted with whole blood, prostaglandin F2 alpha or endothelin. It had a poor effect on vessels precontracted with 60 mM potassium. CONCLUSION--The evidence suggest that the trigemino-cerebrovascular system, storing CGRP and SP, is to a differential degree involved in the pathophysiology of SAH in man and supports the hypothesis of an exhaustion of CGRP as one important factor in the development of late spasm occurring after SAH.

Topics: Adult; Aged; Brain; Calcitonin Gene-Related Peptide; Cerebral Arteries; Female; Humans; Ischemic Attack, Transient; Male; Middle Aged; Neuropeptide Y; Subarachnoid Hemorrhage; Substance P; Vascular Resistance; Vasoactive Intestinal Peptide; Vasomotor System

Calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) are intrinsic vasodilatory substances contained in perivascular nerve fibers innervating large intracranial arteries. Effects of these substances on delayed cerebral vasospasm were examined using a rabbit model of experimental subarachnoid hemorrhage (SAH). Sixty-one anesthetized rabbits received intrathecal fresh arterial blood on day-1 and intrathecal administration of different doses of CGRP, VIP or distilled water on day-4. Prior to the treatment, caliber of the spastic basilar artery was 73.4 +/- 0.9% of pre-SAH values. Serial angiograms after treatment demonstrated that 10(-10)mol/kg of CGRP dilated the spastic artery to 117.1% of pre-SAH levels and that dilatory effect of CGRP continued up to 6 hours after treatment. VIP injection also brought arterial dilatation up to 114.9% of pre-SAH levels, although the duration of the effect was less than 3 hours. Intrathecal administration of CGRP or VIP showed no adverse effect on the systemic and neurological state of the animals. These results indicate that intrathecal CGRP and VIP have therapeutic potential in treating delayed cerebral vasospasm after subarachnoid hemorrhage. Further investigations are expected to extend the effect of CGRP and VIP.

Topics: Animals; Calcitonin Gene-Related Peptide; Disease Models, Animal; Eating; Injections, Spinal; Ischemic Attack, Transient; Rabbits; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide

The involvement of noradrenaline (NA), neuropeptide Y, (NPY), 5-hydroxytryptamine (5-HT), acetylcholine (ACh) and vasoactive intestinal polypeptide (VIP) has been examined in the late phase of spasm after an experimental subarachnoid hemorrhage (SAH) in a rat model. Immunocytochemistry and radioimmunoassay of blood vessels from the circle of Willis did not show significant differences in NPY- and VIP-like immunoreactivity 2 days post SAH as compared to control vessels. The postjunctional effects of NA, NPY, 5-HT, ACh and VIP were studied two days after SAH using a sensitive in vitro system. NPY induced contractions were significantly (p less than 0.01) weaker (lower Emax) in SAH as compared to control rats while the relaxant responses to ACh and VIP were slightly increased after SAH. These observations reveal that in a rat model of SAH, with an approximately 20% in vivo constriction at two days, dynamic changes occur in cerebral artery reactivity despite any obvious change in sympathetic or parasympathetic perivascular nerve networks.

Topics: Acetylcholine; Animals; Basilar Artery; Fluorescent Antibody Technique; Ischemic Attack, Transient; Male; Neuropeptide Y; Norepinephrine; Radioimmunoassay; Rats; Rats, Inbred Strains; Serotonin; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide; Vasoconstriction

Changes in the density of cerebroarterial nerve fibers containing calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP)-like substance, as well as changes in dilatory responses of isolated cerebral arteries to these neuropeptides, after subarachnoid hemorrhage (SAH) were examined in dogs. Moreover, the effects of these neuropeptides to the experimentally produced cerebral arterial spasm were also examined in dogs. SAH was produced by a single injection of fresh autologous arterial blood (1 ml/kg body weight) or double injection of arterial blood (0.5 ml/kg body weight, 48 hours apart) into the cisterna magna. Constriction of basilar artery was most prominent on Day 3 in the single injection model, and on Day 7 in the double injection model. The density of nerve fibers with CGRP-or VIP-like immunoreactivity (LI) was markedly decreased during 7-14 days or 3-7 days after SAH. Vasodilatory actions of CGRP and VIP to isolated basilar artery in vitro were markedly impaired during acute stage of post-SAH period and significantly enhanced during chronic stage of post-SAH period. Intracisternal bolus injection of 10(-10) mol/kg CGRP completely reversed cerebral arterial constriction on Day 3 of single injection SAH model, and intracisternal injection of 10(-11) to 2 x 10(-10) mol/kg CGRP reversed cerebral vasospasm dose-dependently. Intraarterial injection of CGRP could not reversed cerebral arterial constriction. The effects of VIP was much weaker than CGRP.

Topics: Animals; Calcitonin Gene-Related Peptide; Cell Count; Cerebral Arteries; Dogs; In Vitro Techniques; Ischemic Attack, Transient; Nerve Fibers; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide

The vascular relaxation effects of calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP) on the dog basilar artery after experimentally produced subarachnoid hemorrhage (SAH) were examined in vitro by an isometric tension recording method. Both CGRP and VIP induced dose-dependent relaxations in ring segments of the intact basilar artery of control dogs. The vasorelaxant action of CGRP was more potent than that of VIP. The single-injection model of SAH was produced by injection of fresh autologous arterial blood (1 ml/kg body weight) into the cisterna magna on Day 0 of the post-SAH period, and the double-injection model was produced by two injections of blood (0.5 ml/kg each) on Days 0 and 2. Narrowing of the basilar arteries on vertebral angiograms was most prominent on Day 3 or 7 in the single- or double-injection model, respectively. Relaxation of the basilar artery induced by CGRP and VIP was to some extent decreased on Days 3 and 7 of the post-SAH period in the single-injection model, and on Days 7 and 14 in the double-injection model. However, the vasorelaxant effects of CGRP and VIP were significantly enhanced on Day 14 of the post-SAH period in the single-injection model, and on Days 28 and 42 in the double-injection model. Subsequently, these effects returned to control levels by Days 28 or 63 in the single- or double-injection model, respectively.

Topics: Animals; Basilar Artery; Calcitonin Gene-Related Peptide; Disease Models, Animal; Dogs; Female; Male; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide; Vasodilation

Changes of calcitonin gene related-peptide (CGRP)- and vasoactive intestinal polypeptide (VIP)-like immunoreactivities (LI) in cerebrovascular nerve fibers on the dog basilar artery were immunohistochemically examined by using whole-mount preparations after single percutaneous injection of blood components into the cisterna magna. Blood components were prepared from autologous arterial blood. CGRP- and VIP-LI in cerebrovascular nerve fibers were highly suppressed after the injection of washed erythrocytes, but only moderately after the injection of platelet-rich or platelet-poor plasma. The results suggest that erythrocytes may suppress CGRP- and VIP-LI in cerebrovascular nerve fibers after subarachnoid hemorrhage.

Topics: Animals; Basilar Artery; Calcitonin Gene-Related Peptide; Cerebrovascular Circulation; Dogs; Erythrocytes; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide

The influence of subarachnoid hemorrhage (SAH) on vasodilatation induced by vasoactive intestinal polypeptide (VIP) was investigated in rabbit basilar arteries. VIP-induced relaxation was measured in ring sections of the basilar arteries precontracted by 10(-5) M serotonin using an isometric tension recording method. The cyclic adenosine monophosphate (cAMP) content was measured using radioimmunoassay as an indicator of the intracellular mechanism in the arterial smooth muscle cells. VIP (10(-11)-10(-6) M) evoked dose-dependent relaxation of the basilar arteries. The relaxation achieved with 10(-6) M VIP was 85 +/- 4% (n = 7) of the initial contractile tone in control arteries and 47 +/- 5% (n = 8) in the arteries evaluated 2 days after SAH, suggesting that VIP-induced relaxation was suppressed significantly after SAH (P less than 0.01). The cAMP content was significantly higher in the basilar arteries 2 days after SAH (425 +/- 48 pmol/g of tissue, n = 7) than in the control basilar arteries (194 +/- 57 pmol/g of tissue, n = 7). In normal arteries, the cAMP content was increased to a significant degree by VIP (10(-6) M) (325 +/- 60% of control cAMP content, n = 5), whereas the increase was less in the arteries evaluated 2 days after SAH (112 +/- 16% of control cAMP content, n = 5). These results suggest that SAH has an influence on cAMP metabolism in the arteries and that SAH impairs the postsynaptic mechanism of VIP-induced dilatation of the arteries.

Topics: Animals; Basilar Artery; Cyclic AMP; Male; Muscle Relaxation; Rabbits; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide; Vasodilation

The immunoreactivity of vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and neuropeptide Y (NPY)-containing nerve fibers in the basilar artery (BA) and proximal portion of the middle cerebral artery (M1) was immunohistochemically examined in the dog after experimentally produced subarachnoid hemorrhage (SAH). The SAH was produced by a single injection of fresh autologous arterial blood (1 ml/kg body weight) into the cisterna magna. The density (the averaged number of nerve fibers in a unit area) of VIP-, SP-, and NPY-immunoreactive perivascular nerve fibers in the M1 segment and the BA was markedly decreased (5% to 40% of the normal value) immediately after the injection. The density of VIP- and SP-immunoreactive perivascular fibers increased 2 or 3 weeks after SAH and became normal by the 63rd day after injection. On the other hand, no substantial recovery was observed in the density of NPY-immunoreactive perivascular fibers by 63 days after injection.

Topics: Animals; Basilar Artery; Cerebral Arteries; Disease Models, Animal; Dogs; Female; Immunoenzyme Techniques; Male; Nerve Fibers; Neuropeptide Y; Subarachnoid Hemorrhage; Substance P; Vasoactive Intestinal Peptide

A model of subarachnoid hemorrhage (SAH) was experimentally produced in the dog by a single injection of fresh autologous arterial blood into the cisterna magna, and then changes of vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) in perivascular nerve fibers were examined immunohistochemically in the proximal portions of the middle cerebral artery. Perivascular nerve fibers with VIP-LI were markedly decreased in number during the 1st week after SAH. However, they were gradually reincreased during the 2nd to 9th week after SAH to be recovered to the normal level on the 63rd day after SAH.

Topics: Animals; Cerebral Arteries; Dogs; Immunoenzyme Techniques; Nerve Fibers; Subarachnoid Hemorrhage; Vasoactive Intestinal Peptide