[Participation of morphofunctional zones in aging processes]

There are morphofunctional zones in organism tissues, where proliferation and differentiation processes occur. Daughter cells are differentiated in the electric field excited by 12 mother and daughter cell pairs, turned out at cambial cell division. With aging, the cambial cell number is reduced to 7, close to thresholds level (6 cells), at which the differentiation of daughter cells is absent. The depression of cambial cell number with aging is connected with the work of another morphofunctional zone--the hypothalamus, which is the major center of vegetative regulation and initially has very high RhoA activity, which has been established in embryogenesis. Estrogens, influencing over the hypothalamus and activating Src kinase in its nuclei, reduce the level of RhoA activity, including SCN, responsible for many biorhythms of an organism. As a result, the hyperestrogenemia and therefore a connective tissue at first occur. Then there happens a hypoestrogenemia that leads to sharp falling of proliferative activity of cells, causing the depression of cambial cell number and possibility of a malignant tumor development. Along with this, there are the deep lesions of hormone regulation, leading to some lethal diseases. Thus, the RhoA increasing in hypothalamus and especially in SCN circadian rhythm can counteract the Src kinase intensifying and prevent the processes connected with this.