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Concanavalin A increases spontaneous beat rate of embryonic chick heart cell aggregates
Author(s) -
Myrdal Sigrid E.,
Dehaan Robert L.
Publication year - 1983
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041170306
Subject(s) - concanavalin a , lectin , chemistry , biophysics , beat (acoustics) , divalent , chronotropic , heart rate , medicine , endocrinology , microbiology and biotechnology , biology , biochemistry , in vitro , physics , organic chemistry , acoustics , blood pressure
The plant lectin concanavalin A (Con A), at concentrations of 5–200 μg/ml, induced a twofold to fivefold increase in spontaneous beat rate of cultured aggregates of ventricular cells from seven‐day chick embryos. This response was time, dose, and temperature dependent and was accompanied by a decrease in transmembrane potential. It could be blocked or reversed by α‐methyl‐D‐mannoside but was not reversed by dilution alone. Binding of the lectin occurred in the cold, but a temperature‐dependent process was also necessary to produce the response. Divalent (succinyl) Con A did not cause a beat rate increase. Whole heart aggregates responded similarly but less intensely than ventricular aggregates. Atrial aggregates, and whole heart aggregates treated with 5 μg/ml of Con A, produced a biphasic chronotropic response, first decreasing then increasing their beat rates. These results suggest that saccharide‐bearing macromolecules on the heart cell surface play a role in regulating spontaneous beat rate.