[Study of the effect of the cDNA for the human apolipoprotein A-I gene in transgenic rabbits: modeling the neurological syndrome of human Tangier disease]. / Issledovanie na transgennykh krolikakh deistviia kDNK gena apolipoproteid A-I cheloveka: modelirovanie neirologicheskogo sindroma tenzhirskoi bolezni cheloveka.

Two transgenic rabbits which carried human apolipoprotein A-1 (apo A-1) cDNA under mouse ribosomal protein L/32 promoter were obtained. The effectiveness of transgenosis was confirmed by DNA dot/blot and Southern blot hybridizations. Both transgenic animals had paralyses of fore or fore and high limbs. Electron microscopy demonstrated distinct degradative changes of those parts of spinal cord which were responsible for leg skeletal muscle innervation. RNA dot/blot hybridization showed transgene expression in liver and brain but not in kidney of adult transgenic animal. However, analysis of blood serum lipids and immunochemical determinations gave no indications of the presence of human apo A-1 in adult transgenic rabbit. The data obtained allow us to suggest that the observed pathology was due to interference of native and foreign protein products of apo A-1 gene expression in CNS in the course of embryo development. This suggestion was supported by results of in situ hybridization of 5- and 9-week human embryo sections with apo A-1 cDNA, showing effective expression of apo A-1 gene in neural cells of CNS. Results of transgenosis may be viewed as modeling of the neurological syndrome of human Tangier disease.

[Mathematical modelling of charge properties of protein molecules]. / Matematicheskoe modelirovanie zariadovykh svoistv molekul belkov.

A procedure of theoretical determination of the dependence of protein molecule charge on the medium pH has been developed. The suggested procedure allows calculating the protein pI value, the molecule charge at the definite pH value, as well as the corresponding values for the protein molecule. Calculations for insulin, apo A-I and apo A-II molecules have been carried out. Calculated pI values are equal to 5.25, 5.64 and 4.86, respectively. A comparison of the theoretical curves and experimental data allows obtaining information of the molecule structure. Carboxyl groups with abnormally high pK values are discovered, that, probably, indicates to the direct interaction of two COOH-groups. A supposition is made on the most probable arrangement of the functional fragments in apo A-I and apo A-II molecules.

[Modification of blood plasma lipoproteins by a lipid peroxidation product--hexanal]. / Modifikatsiia lipoproteidov plazmy krovi produktom perekisnogo okisleniia lipidov--geksanalem.

HDL treated with hexanal is shown to lose the ability for the cholesterol absorption. In the case of LDL at low concentration of the modifying agent the rate of their elimination from the blood stream of the rabbit decrease, but their uptake by the rat macrophages do not differ from the uptake of native lipoproteins. At high concentration of hexanal the rate of the elimination of LDL from the blood stream increases considerably and is close to that of acetylated LDL. Thus, the modification of plasma lipoproteins with monoaldehydes occurring in the aorta wall leads to the loss of the functional properties of the lipoprotein particles.

[Localization of fluorescent analogs of cholesterol and its esters in lipid models of membranes and lipoproteins]. / Issledovanie lokalizatsii fluorestsentnykh analogov kholesterina i ego éfirov v lipidnykh modeliakh membran i lipoproteinov.

The localization of the fluorescent cholesterol analogue--delta 5,7,9(11)-cholestatrien-3 beta-ol (B-CTE) and its methyl (M-CTE) and stearoyl (St-CTE) esters in model lipid particles were investigated by the radiationless energy transfer. It is shown that 67-100% of B-CTE molecules localize in the phospholipid monolayer of particles containing phosphatidylcholine and triolein (1:2 w/w). The replacement of a hydrogen atom in the hydroxyl by methyl resulted in immersion of 2/3 of the M-CTE molecules to the triolein core. This fact confirmed distribution of the fluorescent probe molecules in the whole volume of lipid particles. St-CTE was practically completely localized in the core of lipid particles. The results obtained evidence for the important role of 3-OH group in keeping the B-CTE molecules in the phospholipid monolayer of the investigated particles.

[Interaction of gastrointestinal peptides and the autonomic nervous system in the contractile function of the gallbladder]. / Vzaimodeistvie zheludochno-kishechnykh peptidov i vegetativnoi nervnoi sistemy v sokratitel'noi funktsii zhelchnogo puzyria.

Within 15 to 30 days after right unilateral subdiaphragmal vagotomy, resection of the anterior liver nervous plexus and mucosoantrumectomy in dogs, the gall bladder contractile function weakens and its adsorbing and concentrating functions are considerably impaired. Within a year these disturbances become less obvious and tend to normalize. These disturbances prove the local hormonal and the autonomic neural control in the gall excreting system. In the digestion phase, neurotensin, angiotensin and enkephalin inhibited the gall bladder motility. This effect was facilitated after sympathectomy and vagotomy due to non-adrenergic inhibitory influences on the gall bladder. Enkephalin might be capable of a direct effect upon the smooth muscles, particularly upon the muscle fibers of the gall bladder's neck. Pentagastrin was found to exert a biphasic effect on the Oddi sphincter tone: exciting the sphincter's circular muscles and inhibiting them with non-cholinergic and non-adrenergic neurons.