QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by MURPHY, D. J. Search for Related Content PubMed Articles by MURPHY, D. J.

Journal of Experimental Biology 69,13-21 (1977)
Published by Company of Biologists 1977

A Calcium-Dependent Mechanism Responsible for Increasing the Freezing Tolerance of the Bivalve Mollusc Modiolus Demissus

DENNIS J. MURPHY ¹

¹ Department of Zoology, University of Maryland, College Park, Maryland 20742; Department of Zoology, Connecticut College, New London, Connecticut 06320

1. A time course of the changes in blood Ca²⁺ and freezing tolerance of Modiolus demissus (Dillwyn) demonstrated that increases in freezing tolerance parallel increases in blood Ca²⁺. The increases in freezing tolerance occurred rapidly, suggesting that Ca²⁺ affects freezing tolerance directly by its presence in the blood.

2. The presence of La³⁺ reduced the freezing tolerance of isolated foot muscle. Thus, Ca²⁺ appears to increase freezing tolerance directly by binding to cell membranes.

3. The loss of the contractile response of freeze-thawed foot muscle to Ach, KCl and caffeine and the continued response to CaCl₂ suggested that cell membranes are the primary sites of freezing injury.

4. The increase in blood Ca²⁺ following low-temperature acclimation accounted for only 40% of the total change in freezing tolerance. Therefore, other mechanisms responsible for increasing the freezing tolerance of M. demissus following low temperature acclimation also exist.

This article has been cited by other articles:

				W. Schmid Survival of frogs in low temperature Science, February 5, 1982; 215(4533): 697 - 698. [Abstract] [PDF]