Ist eine intrazelluläre Eisbildung bei Tieren tödlich? Versuche mit Polypen der GattungLaomedea
✍ Scribed by H. D. Jankowsky; H. Laudien; H. Precht
- Publisher
- Springer-Verlag
- Year
- 1969
- Tongue
- English
- Weight
- 442 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0025-3162
No coin nor oath required. For personal study only.
✦ Synopsis
Is an intmvdlular ice/o~ation in animals lethal? --Experl-men~ with polyp8 o/the genus Many authors axe of the opinJo~ that intTacel]ular freezing causes death of cells. Observations on organisms tolerating intr~el]ular freezing have been regarded not convincing or exceptional. In this investigation, experiments dealing with ~ olyps of the cnidarians ~ flexuvva and L. /oven/ are escribed. A special experimental procedure made it possible to induce, selectively, extTa~ and intxacolln]ar freezing or extracellular freezing alone. Ice crystals could not be observed directly, but darkening of the test individuals is indieaVive of ice formation in the cell; this darkening (flashing or black-out) always follows ice formation in the surroundings. Intracellular ice formation is endured for a short period of time (Fig. I). Small differences in freezing temperature exert great influence on survival rates (Fig. 2). These depend also on the duration of exposure to freezing conditions. Freezing registance is lower after intrace]]ular ice formation; the difference, however, appears to involve quantitative rather than qualitative aspects, although intwacel]ular ice formation could possible destroy protoplasmic structures.