The stability of the behavioral specialization of the neurons

Constancy of connection between the activity of limbic cortex neurones and food-procuring behaviour was studied on rabbits during prolonged unit records. Comparison of activity in the first and the second halves of records was conducted according to the mean frequency during each stage of recording, the mean frequency in each of 10 selected acts of cyclic behaviour and also the probability of activation presence in these acts. It was shown, that behavioural specialization, determined by the criterion of presence of 100% cell activation in specific acts, did not change during recording. The volume of changes in the connection of neurone activity to behaviour in the process of record greatly depended on conditions of recording; at constant mean frequency of neurone activity during the whole time of recording the volume of these changes was minimal.     

The effect of membrane-bound calcium on the activity of adenosine triphosphatase from erythrocytes and erythrocyte permeability for monovalent cations]

The activities of Ca2+, Mg2+-ATPase and Na+, K+-ATPase and the permeability of reconstituted human erythrocytes for Na and K ions were measured, using Ca2+-EGTA, Ca2+ATP and Ca2+-sodium citrate buffers. It was found that the increase in the Ca2+/chelate ratio caused stimulation of Ca2+, Mg2+- and Na+, K+-Atpases and an increase in the rate constants of ouabain--dependent 42K+ influx and 22Na+ efflux from the erythrocytes. The use of the Ca2+-sodium citrate system as a calcium buffer did not change the parameters of the functional state of erythrocyte membranes. The data obtained are discussed in terms of a possible role of calcium ions, which are bound to the inner surface of the erythrocyte membrane, in the regulation of the systems of active and passive transport of cations.     

Synthesis of (5Z,8Z,11Z,14Z)-18- and 19-azidoeicosa-5,8,11,14-tetraenoic acids and their [5,6,8,9,11,12,14,15-H8]-analogues through a common synthetic route

Total synthesis of (5Z,8Z,11Z,14Z)-18- and 19-azidoeicosa-5,8,11,14-tetraenoic acids and their [5,6,8,9,11,12,14,15-³H₈]-analogues via the corresponding p-toluenesulphonates is reported. This synthetic approach allows the preparation of radioactively labelled arachidonic acid derivatives following a common synthetic route. Activity assays indicated that 15-lipoxygenases may tolerate the azido group in the substrate binding pocket and thus, radioactively labelled azido compounds may be used as photo-affinity probes to investigate mechanistic features of eicosanoid biosynthesis.     

Immunochemical determination of the heterogeneity of leukocyte thermostable alpha-glycoprotein

A comparative immunochemical and physico-chemical study of leukocyte thermostable alpha-glycoprotein (LTG) has been performed in pus extract, hemolysate, leukolysate and blood plasma. Immunochemically determined LTG is heterogeneous in respect of molecular charge, sialic acid content and temperature stability. LTG in the blood plasma has a form of alpha-globulin, while in hemolysate it is a beta-globulin, with both forms present in pus. In leukolysate LTG possessing incomplete immunochemical identity with pus and plasma LTG was detected. It is suggested that LTG forms detected differ in their biological activity as well.