Calcified arteries in a gastropod

Area of Science:

• * Invertebrate Biology
• * Biomineralization
• * Comparative Physiology

Background:

• * Calcium deposits are observed in various invertebrate tissues.
• * Arterial calcification has not been previously documented in invertebrate vessels.
• * Spherule cells containing calcium deposits are found in the arteries of Anguispira alternata.

Purpose of the Study:

• * To investigate the presence and nature of calcium deposits in the arterial walls of the land snail Anguispira alternata.
• * To characterize the cellular location and morphology of these deposits.
• * To determine the incorporation of calcium into these structures.

Main Methods:

• * Histological examination of the anterior aorta and major arteries.
• * Identification of calcium deposits within intracellular spherules.
• * Radioisotope tracing using 45Ca injection to track calcium incorporation.

Main Results:

• * Large calcium carbonate deposits were identified within spherule cells lining the arterial walls.
• * These deposits exhibit layered organic and inorganic material.
• * Radioactive 45Ca was rapidly incorporated into the spherule cells after injection.

Conclusions:

• * The land snail Anguispira alternata possesses arterial calcium deposits within specialized cells.
• * These deposits represent a novel occurrence of calcification in invertebrate arterial systems.
• * The physiological role of these arterial calcium deposits remains undetermined.