Paranecrosis

Paranecrosis 

a complex of reversible nonspecific changes that occur in living cells in response to various injurious agents, for example, thermal or mechanical damage and the action of electricity, acids, and narcotic drugs. The term “paranecrosis” was introduced in 1934 by D. N. Nasonov and V. Ia. Aleksandrov by analogy to the concept of parabiosis suggested by N. E. Vvedenskii. In paranecrosis, the capacity of cells to absorb granules of vital stains is suppressed, the stainability of the cytoplasm and nucleus increases, the viscosity and acidity of the cytoplasm increase, the degree of dispersion of cytoplasmic colloids decreases, the cell membrane becomes depolarized, and cell metabolism is disturbed. Paranecrosis is the final stage of the paranecrotic process. The initial phase, which arises during a relatively low exposure to the injurious agent, is characterized by a decrease in the absorption of stains, increase in the degree of dispersion of the cytoplasmic colloids, and hyperpolarization. Paranecrosis involves reversible changes in the intracellular proteins. It is usually accompanied by disturbance of cell functions.

I. P. SUZDAL’SKAIA