Angiotensin II modulates conducted vasoconstriction to norepinephrine and local electrical stimulation in rat mesenteric arterioles.

F Gustafsson; N H Holstein-Rathlou

Angiotensin II modulates conducted vasoconstriction to norepinephrine and local electrical stimulation in rat mesenteric arterioles.

Department of Biomedical Sciences

34 Citations (Scopus)

Abstract

OBJECTIVE: Localized application of a vasoconstricting agent onto the wall of an arteriole results not only in a local constriction of the vessel, but also in a conducted vasoconstriction which is detectable more than a millimeter upstream and downstream from the application site. We investigated the effect of intravenous infusion of angiotensin II (ANG II), losartan or methoxamine on conducted vasoconstriction to local application of norepinephrine (NE) or local electrical stimulation onto the surface of rat mesenteric arterioles in vivo. METHODS: In anesthetized male Wistar rats (n = 43) NE (0.1 mM) or a local depolarizing current was continuously applied onto mesenteric arterioles using micropipettes. Local and conducted vasoconstriction was measured using videomicroscopy. Conducted responses were measured 200-1000 microns upstream from the application site. RESULTS: Systemic infusion of ANG II (4 ng/min) raised mean arterial blood pressure by 6 +/- 2 mm Hg and increased the conducted but not the local vasoconstrictor response to NE (P < 0.02). Infusion of the alpha 1-agonist methoxamine raised blood pressure to the same extent, but did not change conducted vasoconstriction significantly. Blockade of endogenous ANG II by infusion of the AT1-receptor blocker losartan decreased conducted vasoconstriction to NE (P < 0.03). In parallel with the findings using NE, ANG II increased (P < 0.05) and losartan decreased (P < 0.01) conducted vasoconstriction when local electrical stimulation was used to initiate the conducted vascular response. CONCLUSION: The findings suggest that conducted vasoconstriction to NE and local electrical stimulation in rat mesenteric arterioles are modulated by ANG II, an increase in the plasma levels of ANG II increasing conducted vasoconstriction.

Original language	English
Journal	Cardiovascular Research
Volume	44
Issue number	1
Pages (from-to)	176-84
Number of pages	8
ISSN	0008-6363
Publication status	Published - 1999

Cite this

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title = "Angiotensin II modulates conducted vasoconstriction to norepinephrine and local electrical stimulation in rat mesenteric arterioles.",

abstract = "OBJECTIVE: Localized application of a vasoconstricting agent onto the wall of an arteriole results not only in a local constriction of the vessel, but also in a conducted vasoconstriction which is detectable more than a millimeter upstream and downstream from the application site. We investigated the effect of intravenous infusion of angiotensin II (ANG II), losartan or methoxamine on conducted vasoconstriction to local application of norepinephrine (NE) or local electrical stimulation onto the surface of rat mesenteric arterioles in vivo. METHODS: In anesthetized male Wistar rats (n = 43) NE (0.1 mM) or a local depolarizing current was continuously applied onto mesenteric arterioles using micropipettes. Local and conducted vasoconstriction was measured using videomicroscopy. Conducted responses were measured 200-1000 microns upstream from the application site. RESULTS: Systemic infusion of ANG II (4 ng/min) raised mean arterial blood pressure by 6 +/- 2 mm Hg and increased the conducted but not the local vasoconstrictor response to NE (P < 0.02). Infusion of the alpha 1-agonist methoxamine raised blood pressure to the same extent, but did not change conducted vasoconstriction significantly. Blockade of endogenous ANG II by infusion of the AT1-receptor blocker losartan decreased conducted vasoconstriction to NE (P < 0.03). In parallel with the findings using NE, ANG II increased (P < 0.05) and losartan decreased (P < 0.01) conducted vasoconstriction when local electrical stimulation was used to initiate the conducted vascular response. CONCLUSION: The findings suggest that conducted vasoconstriction to NE and local electrical stimulation in rat mesenteric arterioles are modulated by ANG II, an increase in the plasma levels of ANG II increasing conducted vasoconstriction.",

author = "F Gustafsson and Holstein-Rathlou, {N H}",

note = "Keywords: Adrenergic alpha-Agonists; Angiotensin II; Animals; Arterioles; Electric Stimulation; Losartan; Male; Mesenteric Arteries; Methoxamine; Microscopy, Video; Norepinephrine; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin; Vasoconstrictor Agents",

year = "1999",

language = "English",

volume = "44",

pages = "176--84",

journal = "Cardiovascular Research",

issn = "0008-6363",

publisher = "Oxford University Press",

number = "1",

}

TY - JOUR

T1 - Angiotensin II modulates conducted vasoconstriction to norepinephrine and local electrical stimulation in rat mesenteric arterioles.

AU - Gustafsson, F

AU - Holstein-Rathlou, N H

N1 - Keywords: Adrenergic alpha-Agonists; Angiotensin II; Animals; Arterioles; Electric Stimulation; Losartan; Male; Mesenteric Arteries; Methoxamine; Microscopy, Video; Norepinephrine; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Receptor, Angiotensin, Type 2; Receptors, Angiotensin; Vasoconstrictor Agents

PY - 1999

Y1 - 1999

N2 - OBJECTIVE: Localized application of a vasoconstricting agent onto the wall of an arteriole results not only in a local constriction of the vessel, but also in a conducted vasoconstriction which is detectable more than a millimeter upstream and downstream from the application site. We investigated the effect of intravenous infusion of angiotensin II (ANG II), losartan or methoxamine on conducted vasoconstriction to local application of norepinephrine (NE) or local electrical stimulation onto the surface of rat mesenteric arterioles in vivo. METHODS: In anesthetized male Wistar rats (n = 43) NE (0.1 mM) or a local depolarizing current was continuously applied onto mesenteric arterioles using micropipettes. Local and conducted vasoconstriction was measured using videomicroscopy. Conducted responses were measured 200-1000 microns upstream from the application site. RESULTS: Systemic infusion of ANG II (4 ng/min) raised mean arterial blood pressure by 6 +/- 2 mm Hg and increased the conducted but not the local vasoconstrictor response to NE (P < 0.02). Infusion of the alpha 1-agonist methoxamine raised blood pressure to the same extent, but did not change conducted vasoconstriction significantly. Blockade of endogenous ANG II by infusion of the AT1-receptor blocker losartan decreased conducted vasoconstriction to NE (P < 0.03). In parallel with the findings using NE, ANG II increased (P < 0.05) and losartan decreased (P < 0.01) conducted vasoconstriction when local electrical stimulation was used to initiate the conducted vascular response. CONCLUSION: The findings suggest that conducted vasoconstriction to NE and local electrical stimulation in rat mesenteric arterioles are modulated by ANG II, an increase in the plasma levels of ANG II increasing conducted vasoconstriction.

AB - OBJECTIVE: Localized application of a vasoconstricting agent onto the wall of an arteriole results not only in a local constriction of the vessel, but also in a conducted vasoconstriction which is detectable more than a millimeter upstream and downstream from the application site. We investigated the effect of intravenous infusion of angiotensin II (ANG II), losartan or methoxamine on conducted vasoconstriction to local application of norepinephrine (NE) or local electrical stimulation onto the surface of rat mesenteric arterioles in vivo. METHODS: In anesthetized male Wistar rats (n = 43) NE (0.1 mM) or a local depolarizing current was continuously applied onto mesenteric arterioles using micropipettes. Local and conducted vasoconstriction was measured using videomicroscopy. Conducted responses were measured 200-1000 microns upstream from the application site. RESULTS: Systemic infusion of ANG II (4 ng/min) raised mean arterial blood pressure by 6 +/- 2 mm Hg and increased the conducted but not the local vasoconstrictor response to NE (P < 0.02). Infusion of the alpha 1-agonist methoxamine raised blood pressure to the same extent, but did not change conducted vasoconstriction significantly. Blockade of endogenous ANG II by infusion of the AT1-receptor blocker losartan decreased conducted vasoconstriction to NE (P < 0.03). In parallel with the findings using NE, ANG II increased (P < 0.05) and losartan decreased (P < 0.01) conducted vasoconstriction when local electrical stimulation was used to initiate the conducted vascular response. CONCLUSION: The findings suggest that conducted vasoconstriction to NE and local electrical stimulation in rat mesenteric arterioles are modulated by ANG II, an increase in the plasma levels of ANG II increasing conducted vasoconstriction.

M3 - Journal article

C2 - 10615401

SN - 0008-6363

VL - 44

SP - 176

EP - 184

JO - Cardiovascular Research

JF - Cardiovascular Research

IS - 1

ER -

Angiotensin II modulates conducted vasoconstriction to norepinephrine and local electrical stimulation in rat mesenteric arterioles.

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