Kovalenko
R.I., Novikova I.A., Sibarov D.A., Anisimov V.N., Klimashevskii V.F.,Nozdrachev
A.D.
Adaptive Morphofunctional Changes Of Pineal Cells During Tumor Process
In The Large Intestine,
III-International Congress of Pathophysiology, Lahti, Finland, in
Pathophysiology v.5., suppl. 1, p. 154, 1998.
Department
of Physiology, St.-Petersburg State University, St.-Petersburg, Russia;
*N.N.Petrov Institute of Oncology, St.-Petersburg, Russia
The
pineal hormone melatonin has not only high antioxidant and anticancerogene
activity, but also geroprotective properties. Electrophysiological study
of rats with tumors in the large intestine induced with 1,2-dimethylhygrazine
demon strated higher frequency of pineal cells discharging. The summary
frequency of spontaneously active cells increased mainly due to switching
of the cells from regular to pattern activity. It was accompanied with
significant growth of blood melatonin conce ntration. The decrease of
the number of more active “light” pinealocytes was found during tumor
process. In the same time “dark” cells number increased. The signs of
intensive secretion in the “light” cells allows us to suppose their
compensatory activat ion to be adaptive in conditions produced by tumors.
Besides this cells hyperfunction causes further destructive changes
in their ultrastructure (vacuolization, lipidization, partially cytoplasm
lysis and local destructions of cell and nuclear membranes) . The similar
changes of ultrastructure were observed in aged (>22 months) rats.