TY - JOUR

T1 - Vascular pathology of large cerebral arteries in experimental subarachnoid hemorrhage

T2 - Vasoconstriction, functional CGRP depletion and maintained CGRP sensitivity

AU - Johansson, Sara Ellinor

AU - Abdolalizadeh, Bahareh

AU - Sheykhzade, Majid

AU - Edvinsson, Lars

AU - Sams, Anette

N1 - Copyright © 2019 Elsevier B.V. All rights reserved.

PY - 2019/3/5

Y1 - 2019/3/5

N2 - Subarachnoid hemorrhage (SAH) is associated with increased cerebral artery sensitivity to vasoconstrictors and release of the perivascular sensory vasodilator CGRP. In the current study the constrictive phenotype and the vasodilatory effects of exogenous and endogenous perivascular CGRP were characterized in detail applying myograph technology to cerebral artery segments isolated from experimental SAH and sham-operated rats. Following experimental SAH, cerebral arteries exhibited increased vasoconstriction to endothelin-1, 5-hydroxytryptamine and U46419. In addition, depolarization-induced vasoconstriction (60 mM potassium) was significantly increased, supporting a general SAH-associated vasoconstrictive phenotype. Using exogenous CGRP, we demonstrated that sensitivity of the arteries to CGRP-induced vasodilation was unchanged after SAH. However, vasodilation in response to capsaicin (100 nM), a sensory nerve activator used to release perivascular CGRP, was significantly reduced by SAH (P = 0.0079). Because CGRP-mediated dilation is an important counterbalance to increased arterial contractility, a reduction in CGRP release after SAH would exacerbate the vasospasms that occur after SAH. A similar finding was obtained with artery culture (24 h), an in vitro model of SAH-induced vascular dysfunction. The arterial segments maintained sensitivity to exogenous CGRP but showed reduced capsaicin-induced vasodilation. To test whether a metabolically stable CGRP analogue could be used to supplement the loss of perivascular CGRP release in SAH, SAX was systemically administered in our in vivo SAH model. SAX treatment, however, induced CGRP-desensitization and did not prevent the development of vasoconstriction in cerebral arteries after SAH.

AB - Subarachnoid hemorrhage (SAH) is associated with increased cerebral artery sensitivity to vasoconstrictors and release of the perivascular sensory vasodilator CGRP. In the current study the constrictive phenotype and the vasodilatory effects of exogenous and endogenous perivascular CGRP were characterized in detail applying myograph technology to cerebral artery segments isolated from experimental SAH and sham-operated rats. Following experimental SAH, cerebral arteries exhibited increased vasoconstriction to endothelin-1, 5-hydroxytryptamine and U46419. In addition, depolarization-induced vasoconstriction (60 mM potassium) was significantly increased, supporting a general SAH-associated vasoconstrictive phenotype. Using exogenous CGRP, we demonstrated that sensitivity of the arteries to CGRP-induced vasodilation was unchanged after SAH. However, vasodilation in response to capsaicin (100 nM), a sensory nerve activator used to release perivascular CGRP, was significantly reduced by SAH (P = 0.0079). Because CGRP-mediated dilation is an important counterbalance to increased arterial contractility, a reduction in CGRP release after SAH would exacerbate the vasospasms that occur after SAH. A similar finding was obtained with artery culture (24 h), an in vitro model of SAH-induced vascular dysfunction. The arterial segments maintained sensitivity to exogenous CGRP but showed reduced capsaicin-induced vasodilation. To test whether a metabolically stable CGRP analogue could be used to supplement the loss of perivascular CGRP release in SAH, SAX was systemically administered in our in vivo SAH model. SAX treatment, however, induced CGRP-desensitization and did not prevent the development of vasoconstriction in cerebral arteries after SAH.

KW - 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid/pharmacology

KW - Animals

KW - Calcitonin Gene-Related Peptide/pharmacology

KW - Capsaicin/pharmacology

KW - Cerebral Arteries/drug effects

KW - Endothelin-1/pharmacology

KW - Male

KW - Models, Animal

KW - Rats

KW - Rats, Sprague-Dawley

KW - Serotonin/pharmacology

KW - Subarachnoid Hemorrhage/pathology

KW - Vasoconstriction/drug effects

KW - Vasoconstrictor Agents/pharmacology

KW - Vasodilation/drug effects

KW - Vasodilator Agents/pharmacology

U2 - 10.1016/j.ejphar.2019.01.007

DO - 10.1016/j.ejphar.2019.01.007

M3 - Journal article

C2 - 30653947

VL - 846

SP - 109

EP - 118

JO - European Journal of Pharmacology

JF - European Journal of Pharmacology

SN - 0014-2999

ER -