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dc.rights.licenseRestricted to current Rensselaer faculty, staff and students. Access inquiries may be directed to the Rensselaer Libraries.
dc.contributorJohnson, William H.
dc.contributorKrause, Sonja
dc.contributorOdell, Garrett M.
dc.contributorWedler, Frederick C.
dc.contributor.authorHartt, Jacqueline E.
dc.date.accessioned2021-11-03T08:19:03Z
dc.date.available2021-11-03T08:19:03Z
dc.date.created2015-04-10T16:05:55Z
dc.date.issued1975-12
dc.identifier.urihttps://hdl.handle.net/20.500.13015/1332
dc.descriptionDecember 1975
dc.descriptionSchool of Science
dc.description.abstractHigh temperatures (to 30° C) have been seen to reversibly inactivate the catch-like response at pH 6.0, while calcium-contractile activity is unaffected. Higher temperature (above 35°) render the process irreversible. Low temperatures (to 0°) have no effect on either event.
dc.description.abstractAll the effects reported herein serve to support the independent catch hypothesis, especially when viewed together with correlative data obtained from other methods. It is thus strongly suggested that the protein α-paramyosin mediates thick filament aggregation, which in turn is responsible for the economical tension maintenance characteristic of the catch state.
dc.description.abstractSupernatant obtained from the extraction of α-paramyosin was found to decrease the ABRM'S stretch resistance, an effect that was not completely abolished by treatment with high temperatures.
dc.description.abstractMolluscan smooth muscle has long been known for its ability to maintain tension for long periods of time with little or no measurable energy utilization. Over the past half century this phenomenon, called "catch" or "tonus", has been the subject of much debate as to its mechanism of operation.
dc.description.abstractThe two major theories presently in favor are the linkage hypothesis and the independent catch hypothesis. The first of these proposes that the actomyosin linkages, believed to be responsible for development of tension and active shortening, alter their rate of energy utilization to maintain tension economically in the catch state. The independent catch hypothesis attributes the tonic state to the interaction of thick filaments, mediated by the protein so abundant in catch muscles, paramyosin, which is localized at least partially beneath myosin, in the core of the thick filaments.
dc.description.abstractEvidence has been accumulated recently, particularly in the laboratory from which the present work derives, which lends much support to the latter theory. Correlative data have been obtained from the study of light scattering information, electron microscopy, stress-strain and contractile behavior, the solubility characteristics of extracted proteins, and thick filament aggregation. These data, including results in this dissertation, indicate that thick filaments are capable of aggregating with or without the presence of actin and myosin, and that the coalescence follows the aggregation characteristics of paramyosin. Electron micrographs of cross-section of catch muscles show areas populated by thick filaments close enough to interact, with no room for the interposition of actin filaments. The mechanical behavior of catch muscles also implicates the thick filaments, in particular the paramyosin component, in maintenance of the tonic state.
dc.description.abstractStress-strain studies have been performed, using the glycerinated anterior byssus retractor muscle (ABRM) of Mytilus edulis, a catch muscle, under a variety of condition; the contractile response of the muscle was also examined. As has been previously reported, the stretch resistance of the ABRM is highly pH-dependent, with hysteresis evident, a high modulus appearing at low pH (6.0) and a much smaller modulus with increasing pH (to 8.0). This behavior can be correlated with the aggregation of α-paramyosin and thick filaments and with increased forward light scattering in the same pH range. Similar results from these methods have also been obtained with ionic strength; here it has been seen that the stretch resistance values at 0.1 are higher over the pH range 6.0 than those at 0.3.
dc.description.abstractThe metabolic endproduct, lactate ion, has been found to increase the ABRM's elastic modulus. This potentiation is mirrored in its effect on increasing the aggregation of α-paramyosin.
dc.description.abstractVarious glycerination methods have been tested for their effect on pH-dependent stretch resistance and calcium contractions. All preparations evinced acceptable pH dependence, but the phasic response was seen to be more labile. The osmotic shock Rome method and the high temperature Harrington method yielded no detectable contractions; the 50% glycerol-buffer preparations averaged 0.25 kg/cm2; the "quick" methods of Julian and Winegrad gave a better performance, 0.75 kg/cm2.
dc.language.isoENG
dc.publisherRensselaer Polytechnic Institute, Troy, NY
dc.relation.ispartofRensselaer Theses and Dissertations Online Collection
dc.subjectBiology
dc.titleStress-strain behavior of the glycerinated ABRM (anterior byssus retractor muscle), a 'catch' muscle from the mollusc Mytilus edulis
dc.typeElectronic thesis
dc.typeThesis
dc.digitool.pid174884
dc.digitool.pid174885
dc.digitool.pid174886
dc.rights.holderThis electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
dc.description.degreePhD
dc.relation.departmentDept. of Biology


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