Anti-NPPB (N-terminal) monoclonal antibody, clone 2417

Orthostatic hypotension (OH), an independent predictor of mortality and cardiovascular events, strongly correlates with hypertension. Recent genome-wide studies have identified new loci influencing blood pressure (BP) in populations, but their impact on OH remains unknown. A total of 38 970 men and women of European ancestry from five population-based cohorts were included, of whom 2656 (6.8) met the diagnostic criteria for OH (systolic/diastolic BP drop epsilon 20/10 mmHg within 3 min of standing). Thirty-one recently discovered BP-associated single nucleotide polymorphisms (SNPs) were examined using an additive genetic model and the major allele as referent. Relations between OH, orthostatic systolic BP response, and genetic variants were assessed by inverse variance-weighted meta-analysis. We found Bonferroni adjusted (P 0.0016) significant evidence for association between OH and the EBF1 locus (rs11953630, per-minor-allele odds ratio, 95 confidence interval: 0.90, 0.850.96; P 0.001), and nominal evidence (P 0.05) for CYP17A1 (rs11191548: 0.85, 0.750.95; P 0.005), and NPR3-C5orf23 (rs1173771: 0.92, 0.870.98; P 0.009) loci. Among subjects not taking BP-lowering drugs, three SNPs within the NPPA/NPPB locus were nominally associated with increased risk of OH (rs17367504: 1.13, 1.021.24; P 0.02, rs198358: 1.10, 1.011.20; P 0.04, and rs5068: 1.22, 1.041.43; P 0.01). Moreover, an ADM variant was nominally associated with continuous orthostatic systolic BP response in the adjusted model (P 0.04). The overall association between common gene variants in BP loci and OH was generally weak and the direction of effect inconsistent with resting BP findings. These results suggest that OH and resting BP share few genetic components.

Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-alpha (Pdgfra), Ca2+-activated Cl- (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-alpha positive (PDGFR alpha(+)) cells. The imbalance between interstitial cells of Cajal-Anol and PDGFR alpha(+) SK3 distribution might be a potential reason for the colonic dysmotility.