Effect of rapid freezing on the functional state of rat heart mitochondria

As evidenced by respiration, oxidative phosphorylation, ATPase and NADH-oxidase activities, mitochondria composing heart tissue slices are more damaged by freezing-thawing than isolated mitochondria. A change in the functional activity of mitochondria is manifested in an increased respiratory rate in the second metabolic state and decreased respiratory rate in the third metabolic state upon oxidation of succinate and alpha-ketoglutarate; the ability of mitochondria to synthetize ATP (inhibition of the respiratory control) varied and the ATPase and NADH-oxidase activities increased. These changes in the functional state of mitochondria appeared to be due to a rise of the proton conductivity of the inner mitochondrial membrane by freezing-thawing.     

Effect of doxorubicin on the functional state of the mononuclear phagocyte system]

The response of the system of mononuclear phagocytes (SMP) to doxorubicin, an antitumor antibiotic, most widely used in oncological care, was studied. It was shown that a single intraperitoneal administration of doxorubicin to CBA mice in the maximum tolerance doses induced suppression of absorptive SMP capacity and increased IL-I secretion by the bone marrow and peritoneal macrophages both in the stimulated and spontaneous tests in early periods after cytostatic administration. There was a significant rise in the ability of SMP bone marrow elements to respond to the macrophage activating factor, as well as an increase in the cytotoxic activity of bone marrow and peritoneal macrophages.     

Effect of vagotomy on the morphological and functional state of the rat adrenal medulla

After bilateral subphrenic vagotomy in male rats (in 7 and 45 days) there was revealed a sharp dilatation of the venous sinusoids, diminution of the chromaffin tissues area, and a more intensive chromaffin reaction in the adrenal medulla. Vagotomy resulted in a marked alteration of the ultrastructural organization of the secretory cells and the endothelium. Glucose administration to vagotomized animals caused only insignificant variations in adrenaline content in the chromaffin cells. Thus, vagotomy resulted in reduction of the functional activity of the adrenal medulla secretory cells.     

Effect of the functional state of adrenoreceptors on the mitotic activity of regenerating rat liver

Phentolamine, a blocker of alpha-adrenoceptors, given in a single dose (one hour before or 30 minutes, 8 and 24 hours after liver resection) decreased the mitotic index and the coefficient of mitotic phases, and elevated the glycogen content. The number of two-nucleated cells in rats exposed to phentolamine rose 8 hours after resection (p < 0.05). Obsidan, a blocker of beta-adrenoceptors, administered at the same periods, increased the mitotic index and the coefficient of mitotic phases. It is suggested that phentolamine prolonged the late mitotic phases, inhibiting the entry of the cells into mitosis. Obsidan elicited an opposite effect.     

Effect of teratogens on the functional state of the lysosomal segregation apparatus of embryonic hepatocytes

The effect of chloridine, 2-mercaptobenzimidazol, 6-mercaptopurine, dichlorhydrate 2(beta-ethyl aminoethyl) pyridine, pentoxyl, actinomycin D and dimethyl sulfoxide on the functional state of lysosome-segregation system (red acridine granules) was studied in drugs to stabilize the lysosome membrane in the embryonic cells is proved on the basis of experiments with quenching the acridine orange granules adsorbed by the structures with the neutral red molecules.     

Effect of non-fractionated and low-molecular heparin on the functional state of mast cells]

The state of the mast-cell population of rats treated with unfractionated and low-molecular weight heparins under stress conditions has been comparatively studied by the morphometrical assay. The stress was produced by 60 min immobilization followed by intravenous injection of unfractionated (UF) or low-molecular weight (LMW) heparin. The stress-induced heparin release from mast cells resulted in a 3.3-fold decrease of the index of saturation with heparin and in a significant increase of granulolysis and degranulation. The mast cell secretory status reached the preinjection level within 20 min in rats with UF heparin injected (15 unit/200 g). At the same time mast cells of rats with LMW heparin have no such ability. The data obtained indicate that LMW heparin in contrast to UF heparin cannot be accumulated (or accumulated very slowly) by mast cells. This fact as well as low affinity of LMW heparin to endothelium and blood platelets promote its preservation in blood for a long time.     

Effect of ultrasound on the functional state of nicotinic acetylcholine receptors in molluscan neurons

The effect of ultrasound (2.64 MHz, 0.5 W/cm2) on acetylcholine-induced (ACh-induced) current and surface distribution of ACh receptors (AChRs) were studied in neurons of the mollusc Helix pomatia. Upon switching on the ultrasound a negligibly small transient two-phase transmembrane current appeared; prolonged (5-25 min) action of beamed ultrasound waves significantly depressed the ACh-induced chloride current and caused the disappearance of functional nicotinic AChRs on parts of the neuronal soma distant from the axon. Pharmacological studies showed that the disappeared AChRs were responsible for changes in membrane permeability for chloride ions (AChRsCl). The results obtained in the present study indicate that ultrasound may be used as a selective inhibitor of AChRsCl in molluscan neurons.