HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 574/3/947    most recent jphysiol.2006.107672v2 jphysiol.2006.107672v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Snyder, E. M. Articles by Johnson, B. D. Search for Related Content PubMed PubMed Citation Articles by Snyder, E. M. Articles by Johnson, B. D. Related Collections Integrative

Departments of
¹ Internal Medicine
² Anaesthesiology, Mayo Clinic College of Medicine, Rochester, MN55905, USA

The ß₂-adrenergic receptors (ß₂ARs) play a role in renal Na⁺ regulation. Subjects homozygous for glycine at amino acid 16 (Gly16) of the ß₂AR have been shown to have enhanced ß₂-mediated vascular relaxation when compared to subjects homozygous for arginine (Arg16). However, Gly16 subjects have been shown to have higher blood pressure than Arg16 subjects. Given the dominant role of the kidneys in long-term blood pressure regulation, we sought to determine whether there were differences in renal Na⁺ handling between Gly16 (n = 17) and Arg16 (n = 14) subjects (Gly16: age, 30 ± 2 years; body mass index (BMI), 25 ± 11 kg m^–2; Arg16: age, 30 ± 2 years; BMI, 25 ± 1 kg m^–2). We measured urinary Na⁺ content before and for 3 h following rapid intravenous saline infusion (30 ml kg^–1 in 16 min). Prior to the infusion, there were no differences in 24-h Na⁺ excretion between Gly16 and Arg16 subjects (Gly16, 183 ± 21 mmol; Arg16, 184 ± 20 mmol); however, systolic blood pressure (SBP) was significantly higher in Gly16 than Arg16 subjects with no differences observed in diastolic blood pressure (DBP) or mean arterial pressure (MAP) (SBP: Gly16, 117 ± 3 mmHg; Arg16, 109 ± 2 mmHg; DBP: Gly16, 78 ± 2 mmHg; Arg16, 77 ± 2 mmHg; MAP: Gly16, 90 ± 2 mmHg; Arg16, 89 ± 2 mmHg). With rapid saline infusion, MAP increased in both genotype groups (Gly16, 6.7%; Arg16, 3.4%; P > 0.05). In the 3 h following Na⁺ infusion, Na⁺ excretion was less in Gly16 when compared to Arg16 subjects, with a trend towards significance when expressed as total Na⁺ excreted (Gly16, 66 ± 7 mmol; Arg16, 85 ± 9 mmol; P = 0.07), and a significant difference when expressed as a fraction of the administered load (Gly16, 0.18 ± 0.02; Arg16, 0.28 ± 0.03; P < 0.01). These results suggest that the Arg16Gly polymorphism of the ß₂AR is associated with differences in natriuretic response to rapid saline infusion, which may influence long-term regulation of blood pressure.

(Received 16 February 2006; accepted after revision 17 May 2006; first published online 25 May 2006)
Corresponding author E. M. Snyder: Division of Cardiovascular Diseases, Mayo Clinic and Foundation, 200 1st Street, SW Rochester, MN 55905, USA. Email: snyder.eric{at}mayo.edu

This article has been cited by other articles:

				E. M. Snyder, K. C. Beck, S. T. Turner, E. A. Hoffman, M. J. Joyner, and B. D. Johnson Genetic variation of the beta2-adrenergic receptor is associated with differences in lung fluid accumulation in humans J Appl Physiol, June 1, 2007; 102(6): 2172 - 2178. [Abstract] [Full Text] [PDF]

				J. H. Eisenach, D. R. Schroeder, T. L. Pike, C. P. Johnson, W. G. Schrage, E. M. Snyder, B. D. Johnson, V. D. Garovic, S. T. Turner, and M. J. Joyner Dietary sodium restriction and {beta}2-adrenergic receptor polymorphism modulate cardiovascular function in humans J. Physiol., August 1, 2006; 574(3): 955 - 965. [Abstract] [Full Text] [PDF]