The effects of salt-induced hypertension on α1- adrenoreceptor expression and cardiovascular physiology in the rainbow trout (Oncorhynchus mykiss)

Xi Chen, Thomas W. Moon, Kenneth Olson, Ryan A. Dombkowski, Steve F. Perry

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8 Citations (Scopus)

Abstract

Experiments were conducted on rainbow trout to determine the impact of dietary salt on arterial blood pressure. After 4-6 wk, fish fed a salt-enriched diet exhibited a 37% elevation of dorsal aortic pressure (from 23.8 ± 1.2 to 32.6 ± 1.4 mmHg) and an 18% increase in ventral aortic pressure (from 33.0 ± 1.5 to 38.9 ± 1.3 mmHg). The hypertension presumably reflected the increase in cardiac output (from 31.0 ± 0.8 to 36.4 ± 2.2 ml·min-1·kg-1) because systemic and branchial resistances were statistically unaltered by salt feeding. The chronic hypertension was associated with a decrease in the pressor responses of the systemic vasculature to catecholamines and hypercapnia in the salt-fed fish. The reduction in α-adrenergic responsiveness of the systemic vasculature is consistent with desensitization or loss of functional α-adrenoceptors (α-ARs). In support of this idea, the salt-fed fish exhibited significantly decreased levels of α1D-AR mRNA in the dorsal aorta and the afferent (ABA) and efferent branchial arteries (EBA). In contrast, however, the results obtained from norepinephrine dose-response curves for EBA and ABA vascular rings in vitro did not provide evidence for loss of function of branchial artery α1-ARs in the salt-fed fish. Indeed, the EC50 for the EBA norepinephrine dose-response curve was significantly reduced (from 3.75 × 10-7 to 2.12 × 10-7 M) in the salt-fed fish, indicating an increase in the binding affinity of the α1-ARs.

Original languageEnglish
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume293
Issue number3
DOIs
StatePublished - Sep 2007

Fingerprint

Cardiovascular Physiological Phenomena
Oncorhynchus mykiss
Salts
Hypertension
Fishes
Arteries
Arterial Pressure
Norepinephrine
Hypercapnia
Cardiac Output
Adrenergic Agents
Adrenergic Receptors
Catecholamines
Blood Vessels
Aorta
Diet
Messenger RNA

Keywords

  • Afferent branchial artery
  • Blood pressure
  • Efferent branchial artery
  • Epinephrine
  • Hypercapnia
  • Norepinephrine
  • Salt feeding
  • Systemic resistance

ASJC Scopus subject areas

  • Physiology

Cite this

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title = "The effects of salt-induced hypertension on α1- adrenoreceptor expression and cardiovascular physiology in the rainbow trout (Oncorhynchus mykiss)",
abstract = "Experiments were conducted on rainbow trout to determine the impact of dietary salt on arterial blood pressure. After 4-6 wk, fish fed a salt-enriched diet exhibited a 37{\%} elevation of dorsal aortic pressure (from 23.8 ± 1.2 to 32.6 ± 1.4 mmHg) and an 18{\%} increase in ventral aortic pressure (from 33.0 ± 1.5 to 38.9 ± 1.3 mmHg). The hypertension presumably reflected the increase in cardiac output (from 31.0 ± 0.8 to 36.4 ± 2.2 ml·min-1·kg-1) because systemic and branchial resistances were statistically unaltered by salt feeding. The chronic hypertension was associated with a decrease in the pressor responses of the systemic vasculature to catecholamines and hypercapnia in the salt-fed fish. The reduction in α-adrenergic responsiveness of the systemic vasculature is consistent with desensitization or loss of functional α-adrenoceptors (α-ARs). In support of this idea, the salt-fed fish exhibited significantly decreased levels of α1D-AR mRNA in the dorsal aorta and the afferent (ABA) and efferent branchial arteries (EBA). In contrast, however, the results obtained from norepinephrine dose-response curves for EBA and ABA vascular rings in vitro did not provide evidence for loss of function of branchial artery α1-ARs in the salt-fed fish. Indeed, the EC50 for the EBA norepinephrine dose-response curve was significantly reduced (from 3.75 × 10-7 to 2.12 × 10-7 M) in the salt-fed fish, indicating an increase in the binding affinity of the α1-ARs.",
keywords = "Afferent branchial artery, Blood pressure, Efferent branchial artery, Epinephrine, Hypercapnia, Norepinephrine, Salt feeding, Systemic resistance",
author = "Xi Chen and Moon, {Thomas W.} and Kenneth Olson and Dombkowski, {Ryan A.} and Perry, {Steve F.}",
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T1 - The effects of salt-induced hypertension on α1- adrenoreceptor expression and cardiovascular physiology in the rainbow trout (Oncorhynchus mykiss)

AU - Chen, Xi

AU - Moon, Thomas W.

AU - Olson, Kenneth

AU - Dombkowski, Ryan A.

AU - Perry, Steve F.

PY - 2007/9

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N2 - Experiments were conducted on rainbow trout to determine the impact of dietary salt on arterial blood pressure. After 4-6 wk, fish fed a salt-enriched diet exhibited a 37% elevation of dorsal aortic pressure (from 23.8 ± 1.2 to 32.6 ± 1.4 mmHg) and an 18% increase in ventral aortic pressure (from 33.0 ± 1.5 to 38.9 ± 1.3 mmHg). The hypertension presumably reflected the increase in cardiac output (from 31.0 ± 0.8 to 36.4 ± 2.2 ml·min-1·kg-1) because systemic and branchial resistances were statistically unaltered by salt feeding. The chronic hypertension was associated with a decrease in the pressor responses of the systemic vasculature to catecholamines and hypercapnia in the salt-fed fish. The reduction in α-adrenergic responsiveness of the systemic vasculature is consistent with desensitization or loss of functional α-adrenoceptors (α-ARs). In support of this idea, the salt-fed fish exhibited significantly decreased levels of α1D-AR mRNA in the dorsal aorta and the afferent (ABA) and efferent branchial arteries (EBA). In contrast, however, the results obtained from norepinephrine dose-response curves for EBA and ABA vascular rings in vitro did not provide evidence for loss of function of branchial artery α1-ARs in the salt-fed fish. Indeed, the EC50 for the EBA norepinephrine dose-response curve was significantly reduced (from 3.75 × 10-7 to 2.12 × 10-7 M) in the salt-fed fish, indicating an increase in the binding affinity of the α1-ARs.

AB - Experiments were conducted on rainbow trout to determine the impact of dietary salt on arterial blood pressure. After 4-6 wk, fish fed a salt-enriched diet exhibited a 37% elevation of dorsal aortic pressure (from 23.8 ± 1.2 to 32.6 ± 1.4 mmHg) and an 18% increase in ventral aortic pressure (from 33.0 ± 1.5 to 38.9 ± 1.3 mmHg). The hypertension presumably reflected the increase in cardiac output (from 31.0 ± 0.8 to 36.4 ± 2.2 ml·min-1·kg-1) because systemic and branchial resistances were statistically unaltered by salt feeding. The chronic hypertension was associated with a decrease in the pressor responses of the systemic vasculature to catecholamines and hypercapnia in the salt-fed fish. The reduction in α-adrenergic responsiveness of the systemic vasculature is consistent with desensitization or loss of functional α-adrenoceptors (α-ARs). In support of this idea, the salt-fed fish exhibited significantly decreased levels of α1D-AR mRNA in the dorsal aorta and the afferent (ABA) and efferent branchial arteries (EBA). In contrast, however, the results obtained from norepinephrine dose-response curves for EBA and ABA vascular rings in vitro did not provide evidence for loss of function of branchial artery α1-ARs in the salt-fed fish. Indeed, the EC50 for the EBA norepinephrine dose-response curve was significantly reduced (from 3.75 × 10-7 to 2.12 × 10-7 M) in the salt-fed fish, indicating an increase in the binding affinity of the α1-ARs.

KW - Afferent branchial artery

KW - Blood pressure

KW - Efferent branchial artery

KW - Epinephrine

KW - Hypercapnia

KW - Norepinephrine

KW - Salt feeding

KW - Systemic resistance

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JO - American Journal of Physiology

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SN - 0193-1857

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