ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Analysis of the equilibrium of the normal biconcave human red cell, in terms of its tension and a pressure inside, suggests a force of attraction between the opposite membranes at the dimple regions. The analogous attraction that causes rouleaux formation is mediated by long-chain molecules. Single cells hanging on edge between polarizer and analyser, almost “crossed,” were photographed at different angles to the axis of the polarizer. Enlarged prints were scanned by a photometer. For single cells the records showed non-significant fluctuations of intensity, but mean values for 32 cells showed a very significant sinusoidal variation with angle, as predicted by theory for birefringence in the cell at the dimple region. For the rim region, the averaged data showed no variation with angle. In cells moderately osmotically swollen, birefringence in the centre of the dimple region was absent, but persisted close to the inside of the membranes. The latter disappeared in cells further swollen to a biconvex shape. The data is interpreted as indicating oriented chains of molecules across the interior of the cell at the dimple region. The behaviour on swelling was what had been seen in a model with nylon fibres oriented between the charged plates of a condenser, in which the variation of attractive force with distance was adequate to explain the equilibrium of the red cell membrane.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040740202
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