Temperature Dependence of Electric Events in Thylakoid Membranes: Comparison of Membrane Potential, Surface Potential and Aminoacridine Binding

1984 ◽  
pp. 289-292 ◽  
Author(s):  
Ruud Kraayenhof ◽  
José M. G. Torres-Pereira ◽  
Fons A. L. J. Peters ◽  
Harro W. Wong Fong Sang
Keyword(s):  
Membrane Potential ◽  
Temperature Dependence ◽  
Surface Potential ◽  
Potential Surface ◽  
Thylakoid Membranes

Electrical activity of small intestinal smooth muscle and its temperature dependence

1975 ◽  
Vol 229 (5) ◽  
pp. 1268-1276 ◽  
Author(s):  
TY El-Sharkawy ◽  
EE Daniel
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Electrical Activity ◽  
Temperature Dependence ◽  
Intestinal Smooth Muscle ◽  
Plateau Phase ◽  
Control Activity ◽  
Electrical Control ◽  
Electrical Control Activity ◽  
Small Intestinal

Some important features of the intracellularly recorded electrical control activity of rabbit jejunal smooth muscle and its temperature dependence are reported in this study. This activity consisted of repetitive 18-mV depolarizations (control potentials (CP) or slow waves), which at 37degreesC lasted 2 s and had a frequency of 18/min and arose from a membrane potential of --55 mV. In some cells periods between CP's exhibited "diastolic" progressive depolarizations (intercontrol-potential depolarization), which may be the trigger of the CP in driving cells. While CP was usually monophasic, some cells persistently exhibited a notch early in the plateau phase. We suggest that CP consists of two components, an "initial depolarization" and a "secondary depolarization," which are usually fused together to give a monophasic potential. Cooling reduced CP frequency and prolonged its duration and caused more cells to show notching. While amplitude and rate of CP initial depolarization had low Q10's, duration and rates of onset and offset of the secondary depolarization had higher Q10's. Thus, the process responsible for secondary depolarization is more sensitive to temperature thant that underlying initial depolarization of the CP.

Temperature Dependence of the HO2+ ClO Reaction. 1. Reaction Kinetics by Pulsed Photolysis-Ultraviolet Absorption and ab Initio Studies of the Potential Surface

2000 ◽  
Vol 104 (2) ◽  
pp. 308-319 ◽  
Author(s):  
Scott L. Nickolaisen ◽  
Coleen M. Roehl ◽  
Lisa K. Blakeley ◽  
Randall R. Friedl ◽  
Joseph S. Francisco ◽  
...  
Keyword(s):  
Ab Initio ◽  
Temperature Dependence ◽  
Reaction Kinetics ◽  
Potential Surface ◽  
Ultraviolet Absorption ◽  
Pulsed Photolysis

scholarly journals Impact of Ciprofloxacin and Chloramphenicol on the Lipid Bilayer ofStaphylococcus aureus: Changes in Membrane Potential

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Paulina L. Páez ◽  
María C. Becerra ◽  
Inés Albesa
Keyword(s):  
Staphylococcus Aureus ◽  
Membrane Potential ◽  
Cell Membrane ◽  
Surface Potential ◽  
Binding Sites ◽  
Ofstaphylococcus Aureus ◽  
Bacterial Membranes ◽  
Electrostatic Surface Potential ◽  
Number Of Binding Sites ◽  
Resistant Strains

The present study was undertaken to explore the interaction of ciprofloxacin and chloramphenicol with bacterial membranes in a sensitive and in a resistant strains ofStaphylococcus aureusby using 1-anilino-8-naphthalene sulfonate (ANS). The binding of this probe to the cell membrane depends on the surface potential, which modulates the binding constant to the membrane. We observed that these antibiotics interacted with the bilayer, thus affecting the electrostatic surface potential. Alterations caused by antibiotics on the surface of the bacteria were accompanied by a reduction in the number of binding sites and an increase in the ANS dissociation constant in the sensitive strain, whereas in the ciprofloxacin-resistant strain no significant changes were detected. The changes seen in the electrostatic surface potential generated in the membrane ofS. aureusby the antibiotics provide new aspects concerning their action on the bacterial cell.

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