Conformational aspects of beta-trypsin interaction with substrates and pancreatic trypsin inhibitor. III. Catalytic act of trypsin and its inhibition

Basing on the results of the theoretical conformational analysis of the nonbonded and valence complexes of trypsin with substrate molecules, the catalytical act of the enzyme is described in details as a spontaneous process. Conformational aspects of interactions of trypsin with pancreatic trypsin inhibitor are analysed. The complete inhibition process and the geometry of the enzyme-inhibitor complex are described in details. The point amino acid replacements, which will provide for an exclusion of BPTI inhibition and will radically change the specificity of the enzyme are proposed.     

Neutralization by bioantioxidants of virus-induced mutagenesis in cultured human cells

The ability of alpha-tocopherol to neutralize mutational process caused by persistent infection (West Nile virus, strain 229) and primary infection (virus of poliomyelitis, type II) was shown in transplanted amnion and human kidney cells. Antimutagenic effect of the modificator was registered, independently of the regime and succession of applying alpha-tocopherol and inductors.     

Changes in the homeostatic balance of prostacyclin-thromboxane generating systems during experimental social stress

Chronic emotional stress leads to the reduction in prostacycline content in the vascular wall and to the elevation of the malonic aldehyde level in the platelets, with a simultaneous increase of the spontaneous platelet aggregation index. Antistressor and antiaggregation action of the adaptation to high mountains occurs at later times (day 30) in both normal and stress-exposed rats despite the fact that stress-exposed rats yield to normal ones as regards the magnitude of prostacycline activation in the vascular wall. This is accounted for by initial (before adaptation) stress-induced disturbance of the balance between prostacycline and thromboxan.     

The function of the liver mitochondria in rats with experimental cirrhosis undergoing an organ-preserving operation on the spleen]

The effect of splenectomy and of spleen-preserving operation with suture ligation of the left gastric artery on the functional status of liver mitochondria was studied by using 102 white male-rats of mixed population with experimental cirrhosis. The obtained data made it evident that in the immediate postoperative period (from 1 to 3 weeks after the procedure) in the animals of both the first and the second series, the disorder of energetic regulation of mitochondria hepatocytes respiration and the decrease in phosphorylation efficiency had the same tendency, which were seemingly caused by stress-action of the operative trauma. The data accumulated in the more distant postoperative period (8 weeks after the procedure) indicated that the resection of the lower splenic pole in combination with supplementary liver arterialization improved essentially the functional status of mitochondria hepatocytes and was more beneficial in contradistinction to splenectomy.     

The effect of alpha-tocopherol on conditioned reflex activity in adrenaline-induced myocardial dystrophy in rats

Adrenolytic heart defect (AHD) proceeds with the breaking of higher adaptational reactions, i.e. the change of latent period of conditioned active prevention reaction and arising of retrograde amnesia. alpha-Tocopherol--antioxidant prevents the breaking of conditioned reflex activity and sharply reduces the mortality rate in AHD. More effective is the prophylaxis of the brain function breaking and lethality.