Long-term xylem pressure measurements in the lianaTetrastigma voinierianum by means of the xylem pressure probe

Planta ◽  
1995 ◽  
Vol 196 (4) ◽  
pp. 804-813 ◽  
Author(s):  
Rainer Benkert ◽  
Jian-Jun Zhu ◽  
Gertraud Zimmermann ◽  
Roman T�rk ◽  
Friedrich-Wilhelm Bentrup ◽  
...  
Keyword(s):  
Pressure Probe ◽  
Pressure Measurements ◽  
Xylem Pressure ◽  
Xylem Pressure Probe

Long-term xylem pressure measurements in the liana Tetrastigma voinierianum by means of the xylem pressure probe

Planta ◽  
1995 ◽  
Vol 196 (4) ◽  
Author(s):  
Rainer Benkert ◽  
Jian-Jun Zhu ◽  
Gertraud Zimmermann ◽  
Roman T�rk ◽  
Friedrich-Wilhelm Bentrup ◽  
...  
Keyword(s):  
Pressure Probe ◽  
Pressure Measurements ◽  
Xylem Pressure ◽  
Xylem Pressure Probe

scholarly journals Diurnal variation in the radial reflection coefficient of intact maize roots determined with the xylem pressure probe

1997 ◽  
Vol 48 (12) ◽  
pp. 2045-2053 ◽  
Author(s):  
H. Schneider ◽  
N. Wistuba ◽  
B. Miller ◽  
P. Geβner ◽  
F. Thürmer ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Diurnal Variation ◽  
Pressure Probe ◽  
Xylem Pressure ◽  
Maize Roots ◽  
Xylem Pressure Probe

Mechanisms of long-distance water transport in plants: a re-examination of some paradigms in the light of new evidence

1993 ◽  
Vol 341 (1295) ◽  
pp. 19-31 ◽  
Keyword(s):  
Water Transport ◽  
Pressure Probe ◽  
Nmr Imaging ◽  
Long Distance ◽  
Indirect Methods ◽  
Xylem Pressure ◽  
Direct Measurements ◽  
Xylem Pressure Probe ◽  
Cohesion Theory ◽  
New Evidence

According to the widely accepted Cohesion Theory, water is pulled by transpiration from the roots through the xylem to the leaves. It is believed that this process results in the development of large tensions (negative pressures) in the xylem. In this chapter we re-examine some of the indirect methods that were used to support the formulation of this theory. We conclude that because of ambiguities inherent in the interpretation of the results obtained by these approaches the evidence in support of the Cohesion Theory is not conclusive. Direct measurements of xylem pressure in herbaceous plants and tall trees have yielded values of tensions that are inconsistent with the Cohesion Theory. In the light of the data from the xylem pressure probe and nuclear magnetic resonance (NMR)-imaging, we believe that several forces may be responsible for long-distance water transport in plants. These include tension, osmotic pressure, capillary and air-water interfacial forces.

scholarly journals Comparative measurements of xylem pressure in transpiring and non-transpiring leaves by means of the pressure chamber and the xylem pressure probe

1998 ◽  
Vol 49 (327) ◽  
pp. 1757-1760 ◽  
Author(s):  
P. J. Melcher ◽  
F. C. Meinzer ◽  
D. E. Yount ◽  
G. Goldstein ◽  
U. Zimmermann
Keyword(s):  
Pressure Chamber ◽  
Pressure Probe ◽  
Xylem Pressure ◽  
Xylem Pressure Probe

Long-term levosimendan treatment improves systolic function and myocardial relaxation in mice with cardiomyocyte-specific disruption of the Serca2 gene

2013 ◽  
Vol 115 (10) ◽  
pp. 1572-1580 ◽  
Author(s):  
Vigdis Hillestad ◽  
Frank Kramer ◽  
Stefan Golz ◽  
Andreas Knorr ◽  
Kristin B. Andersson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Cardiac Function ◽  
Diastolic Dysfunction ◽  
Systolic Function ◽  
Cytosolic Calcium ◽  
Left Ventricular ◽  
Pressure Measurements ◽  
Human Heart Failure

In human heart failure (HF), reduced cardiac function has, at least partly, been ascribed to altered calcium homeostasis in cardiomyocytes. The effects of the calcium sensitizer levosimendan on diastolic dysfunction caused by reduced removal of calcium from cytosol in early diastole are not well known. In this study, we investigated the effect of long-term levosimendan treatment in a murine model of HF where the sarco(endo)plasmatic reticulum ATPase ( Serca) gene is specifically disrupted in the cardiomyocytes, leading to reduced removal of cytosolic calcium. After induction of Serca2 gene disruption, these mice develop marked diastolic dysfunction as well as impaired contractility. SERCA2 knockout (SERCA2KO) mice were treated with levosimendan or vehicle from the time of KO induction. At the 7-wk end point, cardiac function was assessed by echocardiography and pressure measurements. Vehicle-treated SERCA2KO mice showed significantly diminished left-ventricular (LV) contractility, as shown by decreased ejection fraction, stroke volume, and cardiac output. LV pressure measurements revealed a marked increase in the time constant (τ) of isovolumetric pressure decay, showing impaired relaxation. Levosimendan treatment significantly improved all three systolic parameters. Moreover, a significant reduction in τ toward normalization indicated improved relaxation. Gene-expression analysis, however, revealed an increase in genes related to production of the ECM in animals treated with levosimendan. In conclusion, long-term levosimendan treatment improves both contractility and relaxation in a heart-failure model with marked diastolic dysfunction due to reduced calcium transients. However, altered gene expression related to fibrosis was observed.

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