The nature of the hypermetabolism and tachycardia in cold adaptation and experimental hyperthyroidism

The cross circulation method has been used to study contribution of humoral and nonhumoral components to the origin of hypermetabolism (increased level of basal metabolism) and tachycardia under adaptation to cold and experimental hyperthyroidism. Consumption of oxygen, heart rate and rectal temperature have been studied in periods prior to and during the cross circulation. It is shown that under experimental hyperthyroidism contribution of humoral and nonhumoral factors to the origin of hypermetabolism equals 22 and 78%, while that to genesis of tachycardia--44 and 56%, respectively. Under cold adaptation an increase of the basal metabolism level depends on humoral agents by 77% and on changes of the stationary character only by 23%. The nature of adaptation tachycardia is mainly, of the humoral origin (65%).     

Photodynamic effects of a concanavalin A-chlorin e6 conjugate on human fibroblasts

To minimize the side effect of porphyrin photosensitizers and to reduce their active concentration, chlorine e6 was conjugated with concanavalin A. Photodynamic action of chlorine e6 and concanavalin A-chlorine e6 conjugate has been studied in human skin embryonic fibroblasts. The conjugate appeared to be 5 times more effective as compared to chlorine e6 due to concanavalin A-chlorine e6 endocytosis into intracellular compartments.     

Relation between the characteristic activity of the beta-adrenergic agonist isoproterenol and the percolation properties of cell membrane

Variations in the intrinsic activity of 1-isoproterenol and in the percentage of high affinity beta-receptor complexes have been studied under a changes in the macrostructure of reticulocyte plasma membranes. The fluid lipid fraction have been reduced in the membranes for this by phospholipase A2/BSA treatment. It was accompanied by a progressive decrease in the fraction of beta-receptors that are able to form the high affinity complexes with 1-isoproterenol (receptor--regulatory N-protein complexes). Evaluated with the ability to activate the adenylate cyclase, the intrinsic activity of 1-isoproterenol was decreased from 1 to 0 under with conditions. This variations proved to correlate strongly with each other. Thus, changes in the membrane macrostructure may directly determine an efficiency of hormone actions.     

Effect of radioprotectors on cAMP-dependent protein phosphorylation]

The capacity of radioprotectors (serotonin, aminoethylisothiuronium) to stimulate in radioprotective doses cAMP-dependent protein phosphorylation of the cytozol and nuclei of the mouse liver and of the spleen cytozol was shown in vivo. Radioprotectors were incapable of modulating in vitro the activity of protein kinases and the stimulating effect of cAMP. The data presented and previous investigations suggest that the activation of cAMP-dependent phosphorylation by radioprotectors was due to the increase of intracellular cAMP concentration under the effect of radioprotectors.     

Stability of the alpha-helix structure of oligopeptides

The problem of stabilization of oligopeptide alpha-helix conformation is discussed. The stabilizing role of intramolecular H-bonds and coulombic interactions for single molecules was shown. The influence of media results in the competition for formation of inter and intramolecular H-bonds and for coulombic interactions. High competitive media, eg. water, diminishes alpha-helix stability.