MECHANICAL PROPERTIES OF THE COLLAGENOUS MESOHYL OF CHONDROSIA RENIFORMIS: EVIDENCE FOR PHYSIOLOGICAL CONTROL

Autores/as

  • IAIN C. WILKIE

Resumen

Incidental observations suggest that the collagenous mesohyl of Chondrosia reniformis can undergo reversible changes in stiffness. We investigated the possibility that the mechanical properties of the mesohyl are under direct physiological control by observing the effects of various treatments on the flexural stiffness of beam-shaped samples subjected to bending tests in which their deflection under gravity was recorded after a fixed time interval. The mesohyl is stiffened by elevated Ca2+ concentrations and by the inorganic calcium channel blockers Co2+ and Mn2+, and it is destiffened by Ca2+-free seawater. Treatments that cause membrane disruption stiffen the mesohyl irreversibly, and the mesohyl is also stiffened by a water-soluble factor released when mesohyl is minced. These results suggest that the passive stiffness of the mesohyl is modulated directly by calcium-dependent cellular activities that may include the secretion of a stiffening molecule that interacts directly with the extracellular matrix.

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Publicado

2018-05-23