AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 3 448-R452, Copyright © 1983 by American Physiological Society
Components of mucus of terrestrial slugs (Gastropoda)
I. Deyrup-Olsen, D. L. Luchtel and A. W. Martin
Mucous secretion by the body wall of the terrestrial slugs (Ariolimax
columbianus, Arionidae; and other species) was found to involve at least
three distinct stages--release of vesicles, formation of granules, and
organization of strands. Mucus is stored intracellularly in membrane-bound
vesicles, and these are shed intact from the mucous cells. Disruption of
the vesicle membrane, with release of contents, can be effected by
endogenous lytic agent(s), as well as by exogenous surfactants, lipid
solvents, or hypotonic media. Thereupon 1-micron granules are released.
These may be stable, or they may change to material that is finely granular
or in the form of strands; the transition to strands is facilitated by
shear stress exerted through the fluid containing the mucous components.
Lectins organize, or are organized with, the strands, as evidenced by
agglutination of erythrocytes on them. Mucous formation, as seen in the
living slug, differs markedly from the one-step process of exocytosis of
fluid mucus inferred from studies of mucous membranes fixed for
ultrastructural investigation.
