TY - JOUR

T1 - VIP/PACAP receptors in cerebral arteries of rat

T2 - characterization, localization and relation to intracellular calcium

AU - Erdling, André

AU - Sheykhzade, Majid

AU - Maddahi, Aida

AU - Bari, Ferenc

AU - Edvinsson, Lars

N1 - Copyright © 2013 Elsevier Ltd. All rights reserved.

PY - 2013/2/1

Y1 - 2013/2/1

N2 - BACKGROUND: Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP)-containing nerves surround cerebral blood vessels. The peptides have potent vasodilator properties via smooth muscle cell receptors and activation of adenylate cyclase. The purpose of this study was to describe the effects of two putative VIP/PACAP receptor antagonists and the distribution of the receptor protein in rat brain vessels. METHODS: The vascular effects of VIP, PACAP-27 and PACAP-38 were investigated in segments of rat middle cerebral artery (MCA) by pressurized arteriography, and in a wire myograph. The antagonistic responses to PACAP6-38 and PG99-465 were evaluated. In addition, the receptor subtypes for VIP and PACAP (VPAC(1), VPAC(2) and PAC(1)) were visualized in the rat middle cerebral artery by immunohistochemistry and Western blotting. RESULTS: In the perfusion model, abluminal but not luminal VIP, PACAP-27 and PACAP-38 caused concentration-dependent relaxations of the MCA (27.1±0.2%, 25.2±0.4% and 0.3±0.1%, respectively). In the wire myograph, there was no significant difference in potency of the peptides in the MCA. In both systems, PACAP6-38 and PG99-465 inhibited the VIP induced relaxation. Western blot showed the presence of the receptor proteins in cerebral vasculature and immunohistochemistry showed that all three receptors are present and located in the cytoplasm of smooth muscle cells. CONCLUSION: In both systems, the two blockers antagonized the relaxant VIP effect; the potency order of agonists and the immunohistochemistry suggest the presence of the dilatory VPAC(1) and VPAC(2) receptors on the smooth muscle cells.

AB - BACKGROUND: Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP)-containing nerves surround cerebral blood vessels. The peptides have potent vasodilator properties via smooth muscle cell receptors and activation of adenylate cyclase. The purpose of this study was to describe the effects of two putative VIP/PACAP receptor antagonists and the distribution of the receptor protein in rat brain vessels. METHODS: The vascular effects of VIP, PACAP-27 and PACAP-38 were investigated in segments of rat middle cerebral artery (MCA) by pressurized arteriography, and in a wire myograph. The antagonistic responses to PACAP6-38 and PG99-465 were evaluated. In addition, the receptor subtypes for VIP and PACAP (VPAC(1), VPAC(2) and PAC(1)) were visualized in the rat middle cerebral artery by immunohistochemistry and Western blotting. RESULTS: In the perfusion model, abluminal but not luminal VIP, PACAP-27 and PACAP-38 caused concentration-dependent relaxations of the MCA (27.1±0.2%, 25.2±0.4% and 0.3±0.1%, respectively). In the wire myograph, there was no significant difference in potency of the peptides in the MCA. In both systems, PACAP6-38 and PG99-465 inhibited the VIP induced relaxation. Western blot showed the presence of the receptor proteins in cerebral vasculature and immunohistochemistry showed that all three receptors are present and located in the cytoplasm of smooth muscle cells. CONCLUSION: In both systems, the two blockers antagonized the relaxant VIP effect; the potency order of agonists and the immunohistochemistry suggest the presence of the dilatory VPAC(1) and VPAC(2) receptors on the smooth muscle cells.

U2 - 10.1016/j.npep.2012.12.005

DO - 10.1016/j.npep.2012.12.005

M3 - Journal article

C2 - 23375386

VL - 47

SP - 85

EP - 92

JO - Neuropeptides

JF - Neuropeptides

SN - 0143-4179

IS - 2

ER -