Metabolic Degradation of Catecholamines. The Relative Importance of Different Pathways under Physiological Conditions and after Administration of Drugs

6066Equal significance of longitudinal and radial wall motion represents the normal right ventricular mechanical pattern: 3D echocardiographic study in 231 healthy volunteers

European Heart Journal ◽

10.1093/eurheartj/ehz746.0116 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Cited By ~ 1

Author(s):

A Kovacs ◽

Y Nabeshima ◽

B Lakatos ◽

Y Nagata ◽

M Tokodi ◽

...

Keyword(s):

Ejection Fraction ◽

Right Ventricular ◽

Healthy Volunteers ◽

Left Ventricular ◽

Relative Importance ◽

Free Wall ◽

Radial Wall ◽

Physiological Conditions ◽

Relative Contribution ◽

Rv Function

Abstract Three main mechanisms contribute to right ventricular (RV) pump function: (1) shortening of the longitudinal axis with traction of the tricuspid annulus towards the apex; (2) inward (radial) movement of the RV free wall, which is often referred as the “bellows effect”; and (3) bulging of the interventricular septum into the RV during the left ventricular contraction and stretching of the free wall over the septum (causing shortening in the anteroposterior direction). Despite the established clinical value of the functional changes among the aforementioned components, their relative importance remains to be quantified during physiological conditions. Accordingly, the aim of our study was to evaluate the relative contribution of the different RV motion directions to global RV function on both global and segmental level in a large set of healthy individuals. We have recruited 231 healthy volunteers (44% female, with a wide and balanced age range from 8 to 81 years) from two experienced centers performing transthoracic 3D echocardiography (3DE) on a routine basis. 3DE datasets focused on the RV were obtained using multi-beat acquisition. We determined RV volumes and subsequent ejection fraction (RVEF) by dedicated software. Using the ReVISION method, we have decomposed the motion of the RV to determine longitudinal (LEF), radial (REF) and anteroposterior ejection fraction (AEF). Their ratio to RVEF quantifies the relative contribution of the given component to global RV function. Moreover, regional subvolumes were also analyzed in a 15-segment model. Mean value of RVEF was significantly higher in female subjects compared to male subjects (60±7 vs. 56±7%, p<0.001). The relative contributions of LEF and REF to RVEF were comparable, while the contribution of AEF was significantly lower (LEF/RVEF vs. REF/RVEF vs. AEF/RVEF: 0.48±0.08 vs. 0.49±0.07 vs. 0.39±0.11, p<0.001) in the pooled population as well as in the genders separately. In line with higher RVEF found in women, female gender was associated with a higher longitudinal and radial contribution compared to males, however, AEF was similar (women vs. men; LEF/RVEF: 0.49±0.08 vs. 0.47±0.07, p<0.05; REF/RVEF: 0.50±0.07 vs. 0.48±0.06, p<0.01; AEF/RVEF: 0.38±0.12 vs. 0.40±0.10, p=NS). Interestingly, AEF/RVEF showed a significant deterioration with age (r=−0.354, p<0.001), while age-dependency of the longitudinal and radial contributions were not observed concerning both genders. An age-related decrease could be demonstrated by the volume fractions of the 5 septal volumetric segments (r=−0.229, p<0.001). Motion decomposition and the 15 segments In physiological conditions, the relative importance of longitudinal and radial wall motions is similar in determining global RV function. Aging accompanied by a decrease in anteroposterior shortening, which may point to a deteriorating systolic LV-RV interaction. Our results may facilitate further research concerning the alterations of RV mechanical pattern in various disease states.

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Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050986 ◽

1974 ◽

Vol 32 ◽

pp. 194-195

Author(s):

Å. Thureson-Klein

Keyword(s):

Schwann Cells ◽

Cell Organelles ◽

Giant Mitochondria ◽

Matrix Density ◽

Physiological Conditions ◽

Unmyelinated Axons ◽

Internal Structures ◽

Structural Abnormalities ◽

Cytotoxic Compounds ◽

Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

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Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157991 ◽

1990 ◽

Vol 48 (3) ◽

pp. 90-91

Author(s):

N. Seki ◽

Y. Toyama ◽

T. Nagano

Keyword(s):

Plasma Membrane ◽

Essential Role ◽

Freeze Fracture ◽

Final Concentration ◽

Freeze Fracturing ◽

Physiological Conditions ◽

Epididymal Maturation ◽

Cacodylate Buffer ◽

Sperm Membrane ◽

Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

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