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Effect of vasopressin, oxytocin and LHRH (10 and 20 pg/ml medium) on the proliferation and metabolism of cultured rat bone marrow stromal cells was investigated by methyl-3H-thymidine incorporation, cytochemistry and estimation of enzyme activities. Vasopressin did not change of the activity of tetrahydrofolate dehydrogenase (4HFDH), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PD) and the level of reduced glutathione (GSH). However, the higher concentration of vasopressin significantly lowered the activity of acetylcholinesterase (AchE). As compared with the control cultures, stromal cells grown in the presence of oxytocin showed higher (at lower hormone concentration) and lower (at higher concentration) LDH activity as well as lower G6PD activity (only at higher concentration), while the activity of AchE and the level of GSH was not changed. LHRH significantly increased G6PD and AchE activity and decreased LDH activity in the cultured cells. As revealed by cytochemistry, LHRH specifically enhanced 4HFDH activity in reticular cells.

The study has been carried out on Wistar rats. The aim of the present study was to trace the effect of aluminum on erythroidal cells in bone marrow in rats. The number of proerythroblast after 10 days of experiment with aluminum slowly decreased up to 80 days of experiments. However, the number of basophilic erythroblasts after 10 days insignificantly increased but after 20 days gradually decreased up to 80 days of experiments. The bone marrow polichromatic erythroblasts after 10 days of experiment slightly decreased, however after 20, 40 and 80 days of experiments the values decreased significantly. The quality of orthochromatic erythroblasts after 10 days of experiments dropped and after 20, 40 and 80 days of experiments significantly decreased compared to the control value. Aluminum also brings about histological changes in the bone marrow. The statistical significant reductions of hemoglobin and hematocrit levels were found in the aluminum exposed rats.

This study was carried out on male Wistar rats. The bone marrow activities of acetylcholinesterase (AchE-EC.3.1.1.7.), glutathione reductase (GR-EC.1.6.4.2.) and glucose-6-phosphate dehydrogenase (G6PD-EC.1.1.1.49.) were determined as affected by aluminium. The present experiments have revealed that within the first days there will be an increase in enzyme activity in the bone marrow. Simultaneously a decline in the activity of bone marrow could be observed which occurred later in the first course of the experiment.

The aim of this study was to determine the changes of the basic parameters of the erythrocyte system and the activity of some red blood cell (RBC) enzymes prior to and after a single physical effort leading to exhaustion. The study was carried out on male Wistar rats subjected to running on an electric rotating drum at a speed of 25 m/min. A single exercise caused a decrease in the RBC count, haemoglobin concentration (Hb) and haematocrit (Hct) by 21.9, 16.7 and 16.1%, respectively, and an increase in the reticulocyte count (Ret) by 661.5%. The exercise triggered also changes in the activities of some erythrocytic enzymes: pyruvate kinase (PK) activity increased by 12.4%, glucose-6-phosphate dehydrogenase (G6PD) by 37.8%, glutathione reductase (GR) by 30.8% and acetylcholinesterase (AChE) by 248.7%. These increases in the activities of RBC enzymes can be explained by an increase in the red cells turn-over.

These studies were carried out on male Wistar rats. Erythrocyte and bone marrow activity of glutathione reductase (GR - E.C. 1.6.4.2) and glucose-6-phosphate dehydrogenase (G6PD - E.C. 1.1.1.49) were determined as affected by mercury. Under physiological conditions the above enzymes were found to be markedly more active in the bone marrow than in erythrocytes. The present experiments have revealed that within the first days there will be an increase in enzyme activity in the bone marrow as well as in glutathione reductase in erythrocytes. Simultaneously, a decline in the activity of erythrocytes could be observed which began within the very first days of the experiments as well as a decrease in the bone marrow, which occurred later in the course of the experiment.

The toxicity of antifolate drug therapy on microenvironmental function of hemopoietic marrow stromal cells may be critical enough to justify the development of a simple cell culture model to appraise the dihydrofolate reductase (DHFR)/tetrahydrofolate dehydrogenase (EC 1.5.1.3) (4HFDH) enzymic system in individual stromal cells. The localization and pattern of expression of 4HFDH/DHFR in cultured bone marrow stromal cells were studied in situ in morphologically identifiable cells. The 4HFDH/DHFR expression varies quantitatively and qualitatively according to cell types and thus constitutes specific phenotypic patterns for fibroblastic stromal cells, endothelial cells, monocyte-macrophages, and osteoclast-like cells. Data indicate a good correlation between the labeling of the enzymic expression and the resistance of cells to methotrexate treatment. This conclusion is also supported by similar features shown by cell sublines bearing multiple DHFR gene copies. Levels of 4HFDH/DHFR expression in marrow stromal cells should provide useful markers underlining the effects of cytostatic drugs used in chemotherapy (for example, methotrexate injuries or resistance). The method can be applied to isolated cells, stromal colonies (fibroblast CFU), or whole adherent layers from marrow cultures. Moreover, with this method, enzymic reactions can be carried out in situ and visual correlations between a supportive microenvironment (hemopoietic foci) and the 4HFDH/DHFR levels on the stromal adherent layer are possible.

The studies were carried out on male Wistar rats, where the activity of acetylcholinesterase (AchE-E.C. 3.1.1.7) was determined in red cells and bone marrow under the influence of organic and anorganic mercury compounds. A marked decline in the activity of the enzyme could be noted, along with a more pronounced effect of the organic mercury compound on AchE.

The aim of the present study was to determine the relation between the exercise load used in training and the changes in the basic parameters of the erythrocytic system. The experiments were carried out on 33 Wistar rats (females and males). The animals were forced to run at a velocity of 1.47 km/h inside an electrically-driven rotating drum. The experiments were performed for 35 days. In the 1st - (females) and 2nd - (males) group the exercise period was prolonged by 1 min per day on successive days, and by 2 min per day in the 3rd - (females) and 4th - (males) group. Prior to and after the training period the haemoglobin concentration, haematocrit, erythrocyte and reticulocyte counts were determined in the venous blood. Reticulocytes were divided into four age groups and the percentage each particular age group was calculated. All the trained groups manifested a decrease in haemoglobin concentration, hematocrit values and erythrocyte count and a concomitant elevation of the reticulocyte count with a shift towards youngest forms was found. Rats of the 3rd and 4th groups developed post-exercise anaemia.

The study has been carried out on Wistar rats. The animals were divided into two groups: the control rats received 0.9% saline solution intraperitoneally in there consecutive days. The experimental animals were administered 1% solution of acetylphenylhydrazine (APHZ) intraperitoneally also in three days. Prior to the experiments samples of blood have been collected from tail veins and reticulocyte counts made: the counts had also been determined before the culture of tissue was started. On the fifth day of the primary culture, the morphology and enzymatic activity of the stromal cells of the bone marrow were studied. The cells grown in vitro were cultured by the use of the Eagle's medium enriched with 20% calf serum and L-glutamate. The type of the cells, their number and rate of growth were noted. In the cells the activity of specific esterase as well as acid and alkaline phosphatase was determined. Statistically significant differences between the control and experimental animals were found both in the numbers of stromal cells and in the differences in score values of activity of particular enzymes in various types of cells.

Male and female rats of Wistar strain have been injected with 0.2% HgCl2, 203HgCl2, PbNO3 and 2% APHZ, in the volume of 0.5 ml saline for 4 days. Subbands of G-6-PD enzyme from erythrocytes and bone marrow cells, were separated by disc polyacrylamide electrophoresis. Four subbands of the enzyme resulted electrophoretic separation. In erythrocytes increase of activity of fraction I. and decrease of fraction II were observed, while in bone marrow opposite reaction was visible. In both tissue following administration of Hg and Pb, fractions III and IV disappeared. In the place of disappeared bands increased radioactivity of 203Hg was detected.