STUDIES ON THE ELECTRICAL CHARACTERISTICS OF CHLORIDE REABSORPTION AND BICARBONATE SECRETION BY THE TURTLE BLADDER.
Item
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Title
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STUDIES ON THE ELECTRICAL CHARACTERISTICS OF CHLORIDE REABSORPTION AND BICARBONATE SECRETION BY THE TURTLE BLADDER.
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Identifier
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AAI8212188
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identifier
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8212188
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Creator
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DURHAM, JOHN HENRY COLLIER.
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Contributor
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Dr. William A. Brodsky | Dr. Patrick Eggena
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Date
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1982
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Animal Physiology
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Abstract
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The turtle bladder (Pseudemys scripta) actively reabsorbs Cl and HCO(,3), and secretes HCO(,3). The relationship between this Cl reabsorption and electrical characteristics of the short circuited bladder was examined in order to ascertain whether Cl reabsorption occurs via an electrogenic mechanism. It was found that the addition and removal of Cl to and from the bathing media caused decreases and increases in the short-circuiting current (I(,sc)) across bladders bathed by Na-free, HCO(,3)-containing media. There was a small but significant correlation between the magnitude of this Cl-induced I(,sc) and that of the Cl reabsorption.;In 11 of 27 experiments, the value of the Cl-induced I(,sc) was found to be similar to that of Cl-reabsorption. In 12 others of the 27 experiments, the value of the Cl-induced I(,sc) was found to be less than that of the Cl-reabsorption. These results can not be accounted for by a hypothesis in which it is assumed that Cl-reabsorption does not affect the simultaneous electrogenic transport of other ions.;In this connection, it was found that the bladder apparently possesses a mechanism for electrogenic HCO(,3) secretion. Agents which stimulate this secretion were found to inhibit Cl-reabsorption, indicating that Cl reabsorption and HCO(,3) secretion are not obligatorally coupled.;Using the assumption that the electrogenic reabsorption of Cl does affect the electrogenic secretion and reabsorption of HCO(,3), an equivalent circuit representing the reabsorption of Cl, HCO(,3), and the secretion of HCO(,3) as the result of parallel electrogenic flows of these ions was constructed. This circuit model would qualitatively account for the relationship between the Cl-induced I(,sc) and the Cl reabsorption found in the majority of the bladders studied.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biomedical Sciences
