Dataset Information

Bifurcation Asymmetry of Small Coronary Arteries in Juvenile and Adult Mice.

ABSTRACT: Background: Microvascular bifurcation asymmetry is of significance for regulation of coronary flow heterogeneity during juvenile and adult growth. The aim of the study is to investigate the morphometric and hemodynamic variation of coronary arterial bifurcations in mice of different ages. Methods: Pulsatile blood flows were computed from a Womersley-type model in the reconstructed left coronary arterial (LCA) trees from Micro-CT images in normal mice at ages of 3 weeks, 6 weeks, 12 weeks, 5-6 months, and >8 months. Diameter and flow ratios and bifurcation angles were determined in each bifurcation of the LCA trees. Results: The blood volume and inlet flow rate of LCA trees increase and decrease during juvenile and adult growth, respectively. As vessel diameters decrease, the increased ratios of small to large daughter vessel diameters (Ds /Dl ) result in more uniform flows and lower velocities. There are significant structure-functional changes of LCA trees in mice of >8 months compared with mice of < 8 months. As Ds /Dl increases, the variation trend of bifurcation angle during juvenile growth is different from that during adult growth. Conclusions: Although inlet flows are different in adult vs. juvenile mice, the adult still have uniform flow and low velocity. This is accomplished through a decrease in diameter. The design ensures ordered dispersion of red cells through asymmetric branching patterns into the capillaries.

SUBMITTER: Feng Y

PROVIDER: S-EPMC5962776 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Bifurcation Asymmetry of Small Coronary Arteries in Juvenile and Adult Mice.

Feng Yundi Y Wang Xuan X Fan Tingting T Li Li L Sun Xiaotong X Zhang Wenxi W Cao Minglu M Liu Jian J Li Jianping J Huo Yunlong Y

Frontiers in physiology 20180515

<b>Background:</b> Microvascular bifurcation asymmetry is of significance for regulation of coronary flow heterogeneity during juvenile and adult growth. The aim of the study is to investigate the morphometric and hemodynamic variation of coronary arterial bifurcations in mice of different ages. <b>Methods:</b> Pulsatile blood flows were computed from a Womersley-type model in the reconstructed left coronary arterial (LCA) trees from Micro-CT images in normal mice at ages of 3 weeks, 6 weeks, 12 ...[more]

PMID: 29867562

Similar Datasets

Project description:1. The receptor subtype and mechanisms underlying relaxation to adenosine were examined in human isolated small coronary arteries contracted with the thromboxane A2 mimetic, 1,5,5-hydroxy-11alpha, 9alpha-(epoxymethano)prosta-5Z, 13E-dienoic acid (U46619) to approximately 50% of their maximum contraction to K+ (125 mM) depolarization (Fmax). Relaxations were normalized as percentages of the 50% Fmax contraction. 2. Adenosine caused concentration-dependent relaxations (pEC50, 5.95+/-0.20; maximum relaxation (Rmax), 96.7+/-1.4%) that were unaffected by either combined treatment with the nitric oxide inhibitors, NG-nitro-L-arginine (L-NOARG; 100 microM) and oxyhaemoglobin (HbO; 20 microM) or the ATP-dependent K+ channel (KATP) inhibitor, glibenclamide (10 microM). The pEC50 but not Rmax to adenosine was significantly reduced by high extracellular K+ (30 mM). Relaxations to the adenylate cyclase activator, forskolin, however, were unaffected by high K+ (30 mM). 3. Adenosine and a range of adenosine analogues, adenosine, 2-chloroadenosine (2-CADO), 5'-N-ethyl-carboxamidoadenosine (NECA), R(-)-N6-(2-phenylisopropyl)-adenosine (R-PIA), S(+)-N6-(2-phenylisopropyl)-adenosine (S-PIA), N6-cyclopentyladenosine (CPA), 1-deoxy-1-[6-[[(3-iodophenyl)methyl]amino]-9H-purin-9-yl]-N-methyl-beta- D-ribofuranuronamide (IB-MECA), 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamido adenosine hydrochloride (CGS 21680), relaxed arteries with a rank order of potency of NECA= 2-CADO >adenosine= IB-MECA = R-PIA= CPA > S-PIA)> CGS 21680. 4. Sensitivity but not Rmax to adenosine was significantly reduced approximately 80 and 20 fold by the non-selective adenosine receptor antagonist, 8-(p-sulphophenyl)theophylline (8-SPT) and the A2 receptor antagonist, 3,7-dimethyl-1-propargylxanthine (DMPX). By contrast, the A1-selective antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) had no effect on pEC50 or Rmax to adenosine. 5. These results suggest that A2B receptors mediate relaxation to adenosine in human small coronary arteries which is independent of NO but dependent in part on a K+-sensitive mechanism.

Project description:BackgroundIn the recent years, the use of Doppler-echocardiography has become a standard non-invasive technique in the analysis of cardiac malformations in genetically modified mice. Therefore, normal values have to be established for the most commonly used inbred strains in whose genetic background those mutations are generated. Here we provide reference values for transthoracic echocardiography measurements in juvenile (3 weeks) and adult (8 weeks) 129/Sv mice.MethodsEchocardiographic measurements were performed using B-mode, M-mode and Doppler-mode in 15 juvenile (3 weeks) and 15 adult (8 weeks) mice, during isoflurane anesthesia. M-mode measurements variability of left ventricle (LV) was determined.ResultsSeveral echocardiographic measurements significantly differ between juvenile and adult mice. Most of these measurements are related with cardiac dimensions. All B-mode measurements were different between juveniles and adults (higher in the adults), except for fractional area change (FAC). Ejection fraction (EF) and fractional shortening (FS), calculated from M-mode parameters, do not differ between juvenile and adult mice. Stroke volume (SV) and cardiac output (CO) were significantly different between juvenile and adult mice. SV was 31.93 ± 8.67 ?l in juveniles vs 70.61 ± 24.66 ?l in adults, ? < 0.001. CO was 12.06 ± 4.05 ml/min in juveniles vs 29.71 ± 10.13 ml/min in adults, ? < 0.001. No difference was found in mitral valve (MV) and tricuspid valve (TV) related parameters between juvenile and adult mice. It was demonstrated that variability of M-mode measurements of LV is minimal.ConclusionsThis study suggests that differences in cardiac dimensions, as wells as in pulmonary and aorta outflow parameters, were found between juvenile and adult mice. However, mitral and tricuspid inflow parameters seem to be similar between 3 weeks and 8 weeks mice. The reference values established in this study would contribute as a basis to future studies in post-natal cardiovascular development and diagnosing cardiovascular disorders in genetically modified mouse mutant lines.

Dataset Information

Bifurcation Asymmetry of Small Coronary Arteries in Juvenile and Adult Mice.

Publications

Bifurcation Asymmetry of Small Coronary Arteries in Juvenile and Adult Mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets