The aim of this study was to evaluate the association of single nucleotide polymorphisms (SNPs) T-786C and G894T in the gene encoding eNOS with blood pressu re variability (BPV) in man. Blood pressure was recorded beat-t o-beat at rest three times in periods of one week (5 min, Finapres, breathing at 0.33 Hz) in 152 subjects (19-24 years). Systolic (SBPV0.1r/SBPV 0.1a) and diastolic (DBPV0.1r/DBPV 0.1a) blood pressure variabilities in relative (r.u.) and absolute (mmHg2/Hz) units were determined by the spectral method as spectral po wer at the frequency of 0.1 Hz. Genotypes of both polymorphisms were detected using polymerase chain reaction and re striction analysis using enzymes Msp I and Ban II. Significant diffe rences were observed in BPV among genotypes of T-786C SNP (p<0.05; Kruskal-Wallis), and among haplotypes of both SNPs (p<0.05; Kruskal-Wallis) as well. In T-786C SNP, carriers of less frequent allele (CC homozygotes and TC heterozygotes) showed significantly greater SBPV0.1r and SBPV0.1a compared to TT homozygote s (Mann-Whitney; p<0.05). The G894T variant showed no sign ificant differences, but, both SNPs were in linkage disequilib rium (D’=0.37; p<0.01). Carriers of haplotype CT/CT (CC homozygotes of -786C/T and TT homozygotes of G894T) displaye d significantly greater SBPV0.1r, SBPV0.1a and DBPV0.1a compared to carriers of other haplotype combinations (Kruskal-Wallis; p=0.015, p=0.048, and p=0.026, respectively). In conclusion, the haplotype formed by less frequent alleles of both eNOS variants was associated with increased systolic and diastolic BPV in this study., M. Jíra ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy