, ▁forming ▁a ▁number ▁of ▁pl asma ▁memb rane - bounded ▁apo pt otic ▁bodies ▁which ▁contain ▁nuclear ▁and ▁or ▁cy top las mic ▁elements . ▁The ▁ul tr astr uct ural ▁appearance ▁of ▁ne c ros is ▁is ▁quite ▁different , ▁the ▁main ▁features ▁being ▁mit och ond rial ▁sw elling , ▁pl asma ▁memb rane ▁break down ▁and ▁cell ular ▁dis integration . ▁A po pt osis ▁occurs ▁in ▁many ▁phys i ological ▁and ▁path ological ▁processes . ▁It ▁plays ▁an ▁important ▁role ▁during ▁emb ry onal ▁development ▁as ▁program med ▁cell ▁death ▁and ▁accompan ies ▁a ▁variety ▁of ▁normal ▁in volution al ▁processes ▁in ▁which ▁it ▁serves ▁as ▁a ▁mechanism ▁to ▁remove ▁" un w anted " ▁cells . ▁ ▁In ▁addition , ▁V D AC 3 ▁has ▁been ▁imp licated ▁in ▁card iop rote ction ▁against ▁is chem ia - re per f usion ▁injury , ▁such ▁as ▁during ▁is chem ic ▁pre condition ing ▁of ▁the ▁heart . ▁Although ▁a ▁large ▁burst ▁of ▁re active ▁o xygen ▁species ▁is ▁known ▁to ▁lead ▁to ▁cell ▁damage , ▁a ▁moder ate ▁release ▁of ▁R OS ▁from ▁the ▁mit och ond ria , ▁which ▁occurs ▁during ▁non le th al ▁short ▁episodes ▁of ▁is chem ia , ▁can ▁play ▁a ▁significant ▁trigger ing ▁role ▁in ▁the ▁signal ▁trans du ction ▁path ways ▁of ▁is chem ic ▁pre condition ing ▁leading ▁to ▁reduction ▁of ▁cell ▁damage . ▁It ▁has ▁even ▁been ▁observed ▁that ▁during ▁this ▁release ▁of ▁re active ▁o xygen ▁species