Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/58007

TitleMechanical properties of the compass depressors of the sea-urchin Paracentrotus lividus (Echinodermata, Echinoidea) and the effects of enzymes, neurotransmitters and synthetic tensilin-like protein
Author(s)Wilkie, Iain C
Fassini, Dario
Cullorà, Emanuele
Barbaglio, Alice
Tricarico, Serena
Sugni, Michela
Del Giacco, Luca
Candia Carnevali, M Daniela
KeywordsAcetylcholine
Animals
Arecoline
Biomechanical Phenomena
Cholinergic Agonists
Chondroitin ABC Lyase
Collagen
Hyaluronoglucosaminidase
Ligaments
Mechanotransduction, Cellular
Methacholine Chloride
Movement
Muscarinic Agonists
Muscle Cells
Nicotine
Nicotinic Agonists
Paracentrotus
Piperazines
Stress, Mechanical
Tensile Strength
Viscosity
Issue date2015
PublisherPublic Library of Science (PLOS)
JournalPLoS ONE
Abstract(s)The compass depressors (CDs) of the sea-urchin lantern are ligaments consisting mainly of discontinuous collagen fibrils associated with a small population of myocytes. They are mutable collagenous structures, which can change their mechanical properties rapidly and reversibly under nervous control. The aims of this investigation were to characterise the baseline (i.e. unmanipulated) static mechanical properties of the CDs of Paracentrotus lividus by means of creep tests and incremental force-extension tests, and to determine the effects on their mechanical behaviour of a range of agents. Under constant load the CDs exhibited a three-phase creep curve, the mean coefficient of viscosity being 561±365 MPa.s. The stress-strain curve showed toe, linear and yield regions; the mean strain at the toe-linear inflection was 0.86±0.61; the mean Young's modulus was 18.62±10.30 MPa; and the mean tensile strength was 8.14±5.73 MPa. Hyaluronidase from Streptomyces hyalurolyticus had no effect on creep behaviour, whilst chondroitinase ABC prolonged primary creep but had no effect on secondary creep or on any force-extension parameters; it thus appears that neither hyaluronic acid nor sulphated glycosaminoglycans have an interfibrillar load transfer function in the CD. Acetylcholine, the muscarinic agonists arecoline and methacholine, and the nicotinic agonists nicotine and 1-[1-(3,4-dimethyl-phenyl)-ethyl]-piperazine produced an abrupt increase in CD viscosity; the CDs were not differentially sensitive to muscarinic or nicotinic agonists. CDs showed either no, or no consistent, response to adrenaline, L-glutamic acid, 5-hydroxytryptamine and γ-aminobutyric acid. Synthetic echinoid tensilin-like protein had a weak and inconsistent stiffening effect, indicating that, in contrast to holothurian tensilins, the echinoid molecule may not be involved in the regulation of collagenous tissue tensility. We compare in detail the mechanical behaviour of the CD with that of mammalian tendon and highlight its potential as a model system for investigating poorly understood aspects of the ontogeny and phylogeny of vertebrate collagenous tissues.
TypeArticle
URIhttp://hdl.handle.net/1822/58007
DOI10.1371/journal.pone.0120339
Peer-Reviewedyes
AccessOpen access
Appears in Collections:3B’s - Artigos em revistas/Papers in scientific journals

Files in This Item:
File Description SizeFormat 
10.1371_journal. pone.0120339.pdf908,99 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID