Genetic polymorphisms of purinergic P2Y2 receptor were associated with the susceptibility to essential hypertension in Chinese postmenopausal women

Hypertension has become a prominent public health concern. Essential hypertension (EH) is a polygenic disorder caused by multiple susceptibility genes. It has been previously shown that the purinergic P2Y2 receptor (P2Y2R) regulates blood pressure; however, whether P2Y2R genetic polymorphisms correlate with EH has not been investigated in Chinese. Our study included 500 EH cases and 504 controls who are Chinese postmenopausal women. We used allele-specific polymerase chain reaction (ASPCR) to genotype five single-nucleotide polymorphism (SNPs) in the P2Y2R gene, i.e., rs4944831, rs12366239, rs1783596, rs4382936, and rs10898909. We assessed the association of P2Y2R genetic polymorphisms with EH susceptibility. The results demonstrated that P2Y2R rs4382936A was correlated with a high risk of EH; particularly, the participants with the rs4382936A allele and CA/AA/(CA+AA) genotypes were at higher risks to EH compared to the subjects with the rs4382936C allele and CC genotype. Moreover, haplotype CAG combined by rs1783596-rs4382936-rs10898909 was a susceptible haplotype for EH, whereas haplotype CCG was a protective haplotype for EH. These results may provide new evidence for applying P2Y2R genetic polymorphisms as useful markers in clinic screening or monitoring potential EH cases in a population of Chinese postmenopausal women.

Effects of dynamic cardiomyoplasty on left ventricular systolic and diastolic performance in an acute canine model

Although dynamic cardiomyoplasty (DCMP) is currently being evaluated as an alternative to end-stage congestive heart failure, the overall results of DCMP are variable and inconclusive. We evaluated the effect of classic DCMP on systolic and diastolic cardiac function in normal heart using reliable indicators which minimize the influences of load conditions. Six experimental dogs were evaluated with the acute nonpreconditioning model. The slope of the linear preload recruitable stroke work relationship (Mw) showed a significant increase with latissimus dorsi muscle (LDM) stimulation (postwrap non-stimulation 59.1+/-6.3, postwrap stimulation 98.6+/-9.7 erg cm(-3) x 10(3); P < 0.01), and the x-intercept (V0) was unchanged; these were utilized as the indicators of left ventricular systolic function. The constant of pressure decay (tau) increased after LDM wrap (prewrap 45.8+/-6.0, postwrap nonstimulation 69.3+/-10.3, postwrap stimulation 72.3+/-13.9 ms; P < 0.05), and the peak filling rate was unchanged after LDM wrap, which were utilized as the indicators of diastolic function. We concluded that classic dynamic cardiomyoplasty is effective in assisting systolic cardiac function, but may to some degree have a detrimental effect on the diastolic cardiac function.

Effects of free latissimus dorsi dynamic cardiomyoplasty on left ventricular function

In their experimental approach to dynamic cardiomyoplasty (DCMP), the authors hypothesized that a wrapping method using the proximal part of a free latissimus dorsi muscle (LDM) graft might augment ventricular contractility more than the classic Carpentier's wrapping method. The authors divided 12 mongrel dogs into a pedicled LDM graft group (Group 1, n = 6) and a free LDM graft group (Group 2, n = 6) to evaluate the properties of the different wrapping methods. To evaluate the effect of DCMP on left ventricular systolic and diastolic function, the authors used precise indicators that minimize the influences of load conditions. The slope of the linear preload recruitable stroke work relationship (Mw) and an X-intercept (Vo) were utilized as the indicator of left ventricular systolic function. The constants of pressure decay (tau) and peak filling rate (PFR) were measured to determine diastolic function. All experimental animals were evaluated with the acute, non preconditioning model. Mw was significantly increased with LDM stimulation in both groups (postwrap non stimulation 59.1 +/- 6.3; postwrap stimulation 98.6 +/- 9.7 erg.cm-3. 10(3); p < 0.01 in Group 1, postwrap non stimulation 66 +/- 6.7; postwrap stimulation 155 +/- 15.7 erg.cm-3.10(3), p < 0.001 in Group 2). Stimulated free LDM grafts significantly increased the Mw in comparison to pedicled grafts (p = 0.011). Vo was unchanged in both groups and there was no significant difference between the two groups. Tau increased after LDM wrap in both groups (p < 0.05), but there was no difference between the two groups (tau; prewrap 45.8 +/- 6.0; postwrap non stimulation 69.3 +/- 10.3; postwrap stimulation 72.3 +/- 13.9 msec in Group 1, prewrap 50.0 +/- 6.0; post wrap non stimulation 61.8 +/- 5.0; post wrap stimulation in 64.3 +/- 4.7 msec in Group 2). Peak filling rate was unchanged after LDM wrap in both groups. Free LDM grafts significantly increased left ventricular systolic function compared to the pedicled LDM. Although myocardial relaxation was impaired after LDM wrap in both groups, there was no difference between the two groups. The authors' results emphasize the explicit benefit of utilization of a free LDM graft in respect to left ventricular systolic function; the free LDM grafts have no gross detrimental effect on diastolic function when compared with a pedicle graft in the acute model.

Effects of stimulated free latissimus dorsi muscle graft on LVEDV and LVSW: a new dynamic cardiomyoplasty technique

The effectiveness of dynamic cardiomyoplasty (DCMP) remains controversial. We hypothesized that effectiveness of DCMP using the latissimus dorsi muscle graft (LDMG) depends on the wrapping method. We analyzed pressure-volume relations (PVR), the left ventricular stroke work (LVSW), and the left ventricular end diastolic volume (LVEDV) changes during nonstimulation and stimulation of the LDMG to evaluate the effect of a new wrapping method of DCMP on the LVSW and the LVEDV changes. The new wrapping technique was evaluated in an acute animal experimental model. In 12 mongrel dogs, we performed continuous measurement of the dimensional and pressure dates of the left ventricle (LV) after the DCMP. The measurement was performed 15 min after wrapping during 5 periods. The duration of one measurement period was 15 s. The animals were divided into 2 groups according to the wrapping method. The heart was wrapped with the LDMG using 2 different methods. For Method 1, Carpentier's method, the heart was wrapped primarily with the distal part of the LDMG, the lateral segment. The vasculoneural pedicle of the latissimus dorsi muscle (LDM) was preserved. For Method 2, the LDM was separated, and the vasculoneural pedicle was cut. The medical sternotomy was performed. The thoracodorsal artery of LDMG was anastomosed to the right internal mammary artery, and the thoracodorsal vein was anastomosed to the right atrial appendage. The heart was wrapped primarily with the proximal part of the "free LDMG," the transverse segment. Based on the PVR loops, the changes of the LVSW and the LVEDV in both experimental groups were analyzed. The paired t-test was used for statistical analysis. Using Method 1, the LVSW and the LVEDV showed no significant changes during stimulation (stim) of the LDMG, compared with nonstimulation (nonstim) (LVSW: nonstim, 970 +/- 168 erg x 10(3); stim, 1,181 +/- 203 erg x 10(3); p = 0.126 and LVEDV: nonstim, 36.6 +/- 6.7 ml; stim, 37.2 +/- 6.8 ml; p = 0.36). Using Method 2, the LVSW was increased, and the LVEDV was decreased during stimulation of the free LDMG, compared with nonstimulation (LVSW: nonstim, 694 +/- 117 erg x 10(3); stim, 846 +/- 104 erg x 10(3); p < 0.001 and LVEDV: nonstim, 47.7 +/- 2.8 ml; stim, 46.8 +/- 2.7 ml; p < 0.001). The stimulated free LDMG wrapping of the heart seems to be a more effective wrapping method for DCMP, and it results in an increase of the LVSW and a decrease of the LVEDV, compared with the original Carpentier's method.