Document Detail


Determination of electric field threshold for electrofusion of erythrocyte ghosts. Comparison of pulse-first and contact-first protocols.
MedLine Citation:
PMID:  1504251     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rabbit erythrocyte ghosts were fused by means of electric pulses to determine the electrofusion thresholds for these membranes. Two protocols were used to investigate fusion events: contact-first, and pulse-first. Electrical capacitance discharge (CD) pulses were used to induce fusion. Plots of fusion yield vs peak field strength yielded curves that intersected the field strength axis at positive values (pseudothresholds) which depended on the protocol and decay half time of the pulses. It was found that plots of pseudothreshold vs reciprocal half time were linear for each protocol; when extrapolated to reciprocal half time = 0 (i.e., t----infinity), these lines intersected the ordinate at values of the field strength considered to be the true electrofusion thresholds. In this fashion, the contact-first protocol gave an electrofusion threshold of 46.5 +/- 11.5 V/mm for hemoglobin-free ghosts (white ghosts) and 40.9 +/- 8.8 V/mm for ghosts with fractional hemoglobin (pink ghosts), while the threshold for the pulse-first protocol applied to pink ghosts was determined to be 93.4 +/- 11.0 V/mm. Although the thresholds depended on the electrofusion protocol, plots of critical field strength vs reciprocal time had the same slopes, i.e., approximately 24 Vs/mm. The results suggest that the fusogenic state induced by an electric pulse in either the contact-first protocol or the pulse-first protocol (long-lived fusogenic state) may in fact share a common mechanism, if the two states are not actually identical.
Authors:
Y Wu; J G Montes; R A Sjodin
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biophysical journal     Volume:  61     ISSN:  0006-3495     ISO Abbreviation:  Biophys. J.     Publication Date:  1992 Mar 
Date Detail:
Created Date:  1992-09-23     Completed Date:  1992-09-23     Revised Date:  2010-09-07    
Medline Journal Info:
Nlm Unique ID:  0370626     Medline TA:  Biophys J     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  810-5     Citation Subset:  IM    
Affiliation:
Department of Biophysics, University of Maryland School of Medicine, Baltimore 21201.
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MeSH Terms
Descriptor/Qualifier:
Animals
Electric Stimulation / methods
Erythrocyte Membrane / physiology*,  ultrastructure
Mathematics
Membrane Fusion*
Membrane Potentials
Microscopy, Fluorescence
Rabbits
Regression Analysis
Grant Support
ID/Acronym/Agency:
R01-NS07626/NS/NINDS NIH HHS
Comments/Corrections

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