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Apoptotic cells do not leak (or at least insignificantly seldom). They shrivel and shrink (cf. karyorrhexis), split into smaller and intact apoptotic bodies that are disposed of by macrophages. The membrane does not rupture! Apoptosis is a programmed, a controlled and planned death of the cell (suicide) with minimal harm done to the neighboring cells (cf. anoikis).
If, however, the cell is not supplied with enough blood or oxygen (ischaemia, hypoxia) or is stressed by other noxes or radiation, it will die unexpectedly. The metabolism will shut down. Na+/K+-ATPase will become inactive as soon as ATP has been used up. Eventually, Na+ enters the cell, alongside with water (OH-) to neutralise the electric potential that is caused by the summatively anionic proteins. The influx will precipitate an osmotic pressure that surpasses the stability of the cells membrane. The cell leaks and ruptures and cytoplasmic and finally nuclear substances are expelled and dissolved in the interstitium.
Thus apoptosis is mainly physiological, immunologically silent and inconspicuous altogether, maintaining at least the micro-environment of the dying cell. Necrosis is pathological. 126.96.36.199 (talk) 14:15, 29 March 2011 (UTC)