Cell death – apoptosis v necrosis summary

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The two types of cell death, apoptosis and necrosis, can be compared and contrasted by a number of criteria as a means of summarising them.

Morphology Part 1 of 3

Apoptosis Necrosis
Earliest changes Cell shrinking Cell swelling
Membrane Remains intact; blebbing Loss of integrity
Chromatin Aggregation at the nuclear membrane
Vesicles Formation of membrane-enclosed vesicles (apoptotic bodies) No vesicle formation; lysis
Termination Continued fragmentation into smaller bodies Complete lysis

Biochemistry Part 2 of 3

Apoptosis Necrosis
Regulation Tightly controlled Loss of homeostatic regulation
Energy requirement Energy-dependent Passive; no energy requirement
DNA Non-random fragmentation prior to apoptotic body formation Random fragmentation after cell lysis
Effector mechanisms Caspase cascade

Consequences Part 3 of 3

Apoptosis Necrosis
Extent Localised; individual cells Groups of cells; indiscriminate
Cause Triggered – withdrawal of survival factor or pro-apoptotic stimulus Evoked by significant non-physiological disturbance
Elicited response No inflammatory response and bystander damage Significant inflammatory response and bystander damage