title: Beta-2 adrenoreceptor gene polymorphisms and sympathetic outflow in humans.
abstract: OBJECTIVE
  Previous association studies suggested that common polymorphisms of the beta-2 adrenoreceptor gene leading to glycine for arginine substitution at position 16 or glutamic acid for glutamine substitution at position 27 affect blood pressure. We reasoned that measurements of resting sympathetic nerve traffic could increase the sensitivity of defining a gene phenotype relationship.
  
  
  METHODS
  We studied 111 Caucasian subjects (70 men, 41 women) with blood pressure<140/90 mmHg. We measured electrocardiogram, beat-by-beat finger blood pressure, brachial blood pressure, and muscle sympathetic nerve activity (MSNA) using microneurography. We genotyped the functionally relevant polymorphisms of the beta-2 adrenoreceptor gene by means of allele-specific polymerase chain reaction.
  
  
  RESULTS
  Sympathetic nerve traffic was similar regardless of genotypes. We obtained similar results when we quantified sympathetic nerve traffic as bursts/100 heart beats or as normalized burst area or when we adjusted resting sympathetic nerve traffic for gender, age, and blood pressure. The polymorphism at position 27 affects sympathetic regulation in men. Men with a Glu/Glu genotype had a significant positive correlation between blood pressure and MSNA.
  
  
  CONCLUSIONS
  While our study was not sufficiently powered to detect subtle influences of genetic variability in the beta-2 adrenoreceptor gene on resting sympathetic nerve traffic, a large effect is unlikely. However the observation that beta-2 adrenoreceptor genotype may affect coupling between resting sympathetic nerve traffic and systolic blood pressure deserves to be tested in larger populations.
authors: Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hanover, Germany.
authors: Jens
authors: J
authors: Tank
authors: Karsten
authors: K
authors: Heusser
authors: Andre
authors: A
authors: Diedrich
authors: Dagmara
authors: D
authors: Hering
authors: Friedrich C
authors: FC
authors: Luft
authors: Andreas
authors: A
authors: Busjahn
authors: Atakan
authors: A
authors: Aydin
authors: Janusz
authors: J
authors: Limon
authors: Krzysztof
authors: K
authors: Narkiewicz
authors: Jens
authors: J
authors: Jordan
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics* / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000502:physiology
chemical_list: D018343:Receptors, Adrenergic, beta-2