Calcification of Trichina Cysts in vitro ∗

Summary

1. Trichina cysts did not calcify spontaneously in vitro, even when exposed to media with high Ca⁺⁺ x P products. 2. When calcification was initiated in vivo, by administration of toxic doses of viosterol over a period of several days, incubation with serum in vitro led to a marked increase in the amount of calcification of the cysts. 3. Calcification of the cysts, when it occurred at all, occurred at Ca⁺⁺x P products well below the critical point for the calcification of rachitic cartilage. 4. The action of viosterol in predisposing to calcification, both in vivo and in vitro, is attributed to a toxic effect upon the cyst or the worm. 5. An enzyme which hydrolyzes glycerophosphate is present in trichina cysts. It is present in the absence of administration of viosterol, which did not affect either its concentration or its distribution. It is present in the cysts for several months before calcification usually occurs spontaneously in vivo in rats.