Probable Mechanisms of the Effects of Cerebral on Morphological Characteristics of Rat Pheochromocytoma Cells

Effects of a recently proposed organic preparation, Cerebral, used in the treatment of some vascular brain pathologies, were examined on cultured rat pheochromocytoma PC-12 cells. The normal culture media in six of the seven groups of cell cultures were replaced by similar media with the addition of 0.2 or 2.0 mg/ml Cerebral, 400 mg/ml nerve growth factor (NGF), 1.0 μM verapamil, a blocker of high-threshold calcium channels, or combinations of the above Cerebral concentrations with 1.0 μM verapamil. Within six days of the test period, we measured mean values of the density of cultured cells, proportions of the units possessing significant processes, and projective areas of the cell somata; according to the latter parameter, conventional diameters of the cells (diameters of the circles equivalent to the above area) were calculated. Culturing of PC-12 cells under control conditions (in the non-modified medium) was not accompanied by transformation of their overwhelming majority into neuron-like units. Cerebral in both tested concentrations significantly suppressed proliferation of PC-12 cells, intensified the formation of processes (some of which demonstrated a typical neurite-like structure), and led to an increase in the dimension of the cells. Under conditions of the action of NGF, similar effects were observed, but their intensity was greater. Manifestations of cell differentiation induced by Cerebral developed with a greater delay and were smoothed earlier, as compared with the respective NGF effects. The addition of 1.0 μM verapamil to the culture medium promoted the process of cell differentation; the effects observed were comparable with results of the action of Cerebral. Combinations of verapamil with Cerebral in both above-mentioned concentrations provided somewhat more intense modulatory effects on PC-12 cells than isolated applications of Cerebral, but the effects observed were not additive. The probable mechanisms of changes in the morphological characteristics of PC-12 cells under the influence of Cerebral and the dependence of such changes on the state of calcium signalization are discussed. The data obtained agree with a supposition that the active substances of Cerebral correspond to trophinotropins initiating and/or intensifying synthesis of NGF.