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The cercarial tail in Proterometra macrostoma (Digenea: Azygiidae): permeability and fine structure of the tegument.
J Parasitol. 2000 Jun; 86(3):616-8.JP

Abstract

Permeability of the cercarial tail in Proterometra macrostoma was examined in vitro with 1 mM 3H-glucose, which tails absorb by diffusion alone. Naturally emerged cercariae (bodies withdrawn into tails) were permeable, but they rapidly (3 min) equilibrated with glucose in the bathing medium and maintained steady state for 4 hr. Metabolism of absorbed glucose was not detectable until after 90 min, and radioactivity in bodies dissected from tails after 4 hr was negligible. On the basis of cercarial water content (90% of total weight) and absorbed isotope at steady state, the calculated volume of the equilibrating compartment was 4% of an intact cercaria. This value correlated well with that of the tegument (3-5%), which was 1-2 microm thick as seen by transmission electron microscopy. A continuous, electron-dense basal membrane/lamina separated the tegument from subtegument. We conclude that the glycocalyx and external plasma membrane are freely permeable, whereas the basal membrane is the barrier that effectively isolated the subtegument from exogenous glucose. The basal membrane also may be the primary structure that protects the subtegument and cercarial body from effects of osmotic stress.

Authors+Show Affiliations

School of Biological Sciences, University of Kentucky, Lexington 40506, USA.No affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

10864263

Citation

Braham, G W., and G L. Uglem. "The Cercarial Tail in Proterometra Macrostoma (Digenea: Azygiidae): Permeability and Fine Structure of the Tegument." The Journal of Parasitology, vol. 86, no. 3, 2000, pp. 616-8.
Braham GW, Uglem GL. The cercarial tail in Proterometra macrostoma (Digenea: Azygiidae): permeability and fine structure of the tegument. J Parasitol. 2000;86(3):616-8.
Braham, G. W., & Uglem, G. L. (2000). The cercarial tail in Proterometra macrostoma (Digenea: Azygiidae): permeability and fine structure of the tegument. The Journal of Parasitology, 86(3), 616-8.
Braham GW, Uglem GL. The Cercarial Tail in Proterometra Macrostoma (Digenea: Azygiidae): Permeability and Fine Structure of the Tegument. J Parasitol. 2000;86(3):616-8. PubMed PMID: 10864263.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The cercarial tail in Proterometra macrostoma (Digenea: Azygiidae): permeability and fine structure of the tegument. AU - Braham,G W, AU - Uglem,G L, PY - 2000/6/23/pubmed PY - 2000/7/8/medline PY - 2000/6/23/entrez SP - 616 EP - 8 JF - The Journal of parasitology JO - J. Parasitol. VL - 86 IS - 3 N2 - Permeability of the cercarial tail in Proterometra macrostoma was examined in vitro with 1 mM 3H-glucose, which tails absorb by diffusion alone. Naturally emerged cercariae (bodies withdrawn into tails) were permeable, but they rapidly (3 min) equilibrated with glucose in the bathing medium and maintained steady state for 4 hr. Metabolism of absorbed glucose was not detectable until after 90 min, and radioactivity in bodies dissected from tails after 4 hr was negligible. On the basis of cercarial water content (90% of total weight) and absorbed isotope at steady state, the calculated volume of the equilibrating compartment was 4% of an intact cercaria. This value correlated well with that of the tegument (3-5%), which was 1-2 microm thick as seen by transmission electron microscopy. A continuous, electron-dense basal membrane/lamina separated the tegument from subtegument. We conclude that the glycocalyx and external plasma membrane are freely permeable, whereas the basal membrane is the barrier that effectively isolated the subtegument from exogenous glucose. The basal membrane also may be the primary structure that protects the subtegument and cercarial body from effects of osmotic stress. SN - 0022-3395 UR - https://www.unboundmedicine.com/medline/citation/10864263/The_cercarial_tail_in_Proterometra_macrostoma__Digenea:_Azygiidae_:_permeability_and_fine_structure_of_the_tegument_ L2 - http://www.journalofparasitology.org/doi/10.1645/0022-3395(2000)086[0616:TCTIPM]2.0.CO;2?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -