Address of Corresponding Author

J Vasc Res 2004;41:517-524 (DOI: 10.1159/000081808)

  Key Words

• Arteriole
• Acetylcholine
• Hypertension
• Gap junction
• Alpha adrenergic
• Sympathetic nervous activity

  Abstract

Arteriolar vasomotor responses can include a component that conducts along the vessel through gap junction channels. This study examined conducted vasomotor responses in arterioles of the hypertensive hamster. The cremaster muscle of normotensive (CHF-148) and spontaneously hypertensive (CHF-H4) hamsters was exteriorized. Micropipettes containing phenylephrine (0.1 M) or acetylcholine (ACh; 1.0 M) were positioned along second-order arterioles and diameter responses were recorded locally for every 0.4 mm upstream to 1.6 mm. Substantative local constrictions to phenylephrine(PE) were poorly conducted to the 0.4-mm site in normotensive and hypertensive hamsters. Local dilation to ACh decayed by 3 ± 1 µm/mm as it conducted along arterioles of the normotensive hamster. In contrast, conducted dilation decayed by 7 ± 1 µm/mm (p < 0.05) in the hypertensive hamster. This hypertension-induced increase in decay was reversed by -adrenergic receptor blockade (phentolamine: 1 µM). However, arteriolar constriction to global ₁- (PE) and ₂- (clonidine) adrenergic agonists was unaffected by hypertension. Rather, sympathetic nervous activity was elevated in the hypertensive hamster as indicated by a greater reduction in arterial pressure upon sympathetic ablation (hexamethonium infusion: 30 mg/kg). This study provides the first evidence that vascular cell-cell communication is altered by the elevated sympathetic nervous activity observed in the hypertensive hamster.

Copyright © 2004 S. Karger AG, Basel

  Author Contacts

David T. Kurjiaka, PhD
Department of Biological Sciences, Ohio University
302 Wilson Research
Athens, OH 45701 (USA)
Tel. +1 740 593 2271, Fax +1 740 593 0300, E-Mail kurjiaka@ohiou.edu

  Article Information

This study was supported by the Ohio Valley Affiliate of the American Heart Association (Beginning Grant in Aid 9960363V) and the Ohio University Research Council.

Received: March 5, 2004
Accepted after revision: August 16, 2004
Published online: October 28, 2004
Number of Print Pages : 8
Number of Figures : 6, Number of Tables : 0, Number of References : 31