Association of C825T polymorphism of G protein beta3 subunit with the autonomic nervous system in young healthy Japanese individuals.
BACKGROUND
The T allele of the C825T polymorphism of the G protein beta3 subunit gene (GNB3) is reported to be associated with increased intracellular signal transduction and the prevalence of essential hypertension. Because the two major receptors in the autonomic nervous system (ANS), the adrenergic and muscarinic acetylcholine receptors, are G protein-coupled receptors, it was expected that the GNB3 C825T polymorphism was associated with ANS function. In the present study, we have investigated the association of this polymorphism with ANS in young, healthy Japanese male individuals.


METHODS
A total of 94 young, healthy subjects underwent the genotyping for the GNB3 C825T polymorphism and electrocardiogram R-R interval power spectral analysis in supine rest and standing positions.


RESULTS
There were no significant differences among genotypes in any of the characteristics investigated (body mass index, blood pressure, plasma glucose, insulin, lipids, and family history of hypertension, diabetes, or obesity). However, in power spectral analysis of heart rate variability, the very-low-frequency component when standing was higher in TT carriers than in CC carriers, and TT and CT carriers had a significantly higher sympathetic nervous system (SNS) index and lower parasympathetic nervous system (PNS) index when standing than CC carriers. In addition, we found that TT carriers showed no chronological variations in either SNS or PNS index after postural change.


CONCLUSIONS
These observations suggested that GNB3 C825T polymorphism is associated with ANS in youth. These findings raise the possibility that individuals who are T allele carriers are at increased risk for developing hypertension in relation to ANS function.
Matsunaga
Tetsuro
T
Laboratory of Metabolism, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan.
Nagasumi
Kae
K
Yamamura
Tsubasa
T
Gu
Ning
N
Nishikino
Mariko
M
Ueda
Yukihiko
Y
Moritani
Toshio
T
Aoki
Norihiko
N
Tsuda
Kinsuke
K
Yasuda
Koichiro
K
D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics*; D001341:Autonomic Nervous System / Q000502:physiology*; D003596:Cytosine; D004562:Electrocardiography; D005787:Gene Frequency; D006339:Heart Rate / Q000502:physiology; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology; D011110:Polymorphism, Genetic; D011187:Posture / Q000502:physiology; D012016:Reference Values; D013564:Sympathetic Nervous System / Q000502:physiology; D013941:Thymine
C454420:G-protein beta3 subunit; D003596:Cytosine; D020962:Heterotrimeric GTP-Binding Proteins; D013941:Thymine