Expression of the P2Y1 nucleotide receptor in chick muscle: its functional role in the regulation of acetylcholinesterase and acetylcholine receptor.

In vertebrate neuromuscular junctions, ATP is stored at the motor nerve terminals and is co-released with acetylcholine during neural stimulation. Here, we provide several lines of evidence that the synaptic ATP can act as a synapse-organizing factor to induce the expression of acetylcholinesterase (AChE) and acetylcholine receptor (AChR) in muscles, mediated by a metabotropic ATP receptor subtype, the P2Y(1) receptor. The activation of the P2Y(1) receptor by adenine nucleotides stimulated the accumulation of inositol phosphates and intracellular Ca(2+) mobilization in cultured chick myotubes. P2Y(1) receptor mRNA in chicken muscle is very abundant before hatching and again increases in the adult. The P2Y(1) receptor protein is shown to be restricted to the neuromuscular junctions and colocalized with AChRs in adult muscle (chicken, Xenopus, and rat) but not in the chick embryo. In chicks after hatching, this P2Y(1) localization develops over approximately 3 weeks. Denervation or crush of the motor nerve (in chicken or rat) caused up to 90% decrease in the muscle P2Y(1) transcript, which was restored on regeneration, whereas the AChR mRNA greatly increased. Last, mRNAs encoding the AChE catalytic subunit and the AChR alpha-subunit were induced when the P2Y(1) receptors were activated by specific agonists or by overexpression of P2Y(1) receptors in cultured myotubes; those agonists likewise induced the activity in the myotubes of promoter-reporter gene constructs for those subunits, actions that were blocked by a P2Y(1)-specific antagonist. These results provide evidence for a novel function of ATP in regulating the gene expression of those two postsynaptic effectors.

[Intercellular information transfer in the process of immunogenesis. VI. The induction of antiphage antibody synthesis in the cells of rat transplantable lymphosarcoma under the influence of splenic RNA from rats and mice immunized with phage T2]. / O mezhkletochnoi peredache informatsii v protsesse immunogeneza. VI. Induktsiia sinteza antifagovykh antitel v kletkakh perevivnoi limfosarkomy krys pod vliianiem RNK selezenki krys i myshei, immunizirovannykh fagom T2.

It has been proved that nuclear and cytoplasmic RNAs, isolated from spleens of T2 phage immunized rats and mice, can induce T2 phage antibodies in cells of the transplantable rat lymphosarcoma. With the nuclear RNA from rat spleens, the effect is persisting in a number of subsequent cell generations. The data presented are principally in accord with results of the authors' previous studies in which lymphosarcoma cells were treated with RNA extracted from spleens of rat immunized with sheep red cells. These results well compare with the authors' earlier advanced hypothesis suggesting a possible involvement of RNA in deblockation of genes responsible for the synthesis of the antibodies in question.

[Effect of preparations of messenger RNA from the spleens of immunized rats on antibody synthesis in rat lymphosarcoma]. / Vliianie preparatov informatsionnykh RNK selezenki immunizirovannykh krys na sintez antitel v krysinoi limfosarkome

Messenger RNA was isolated from spleen polysomes of rats immunized with sheep red cells, two methods being employed: a sorption of mRNA on on membrane filters, and poly(U)-cellulose affinity chromatography. The rat transplantable lymphosarcoma cells treated with this RNA started hemolysine synthesis which persisted throughout many cell generations in transplantation of the tumor. The probability is discussed of m-RNA not only functioning as a template for antibody synthesis but also deblocating appropriate genes in recipient cells.

[Intercellular transmission of information in the process of immunogenesis. V. Study of the role of low-molecular "immune" nuclear RNA in the synthesis of antibodies by rat transplantable lymphosarcoma cells]. / O mezhkletochnoi peredache informatsii v protsesse immunogeneza. V. Izuchenie roli nizkomolekuliarnoi "immunnoi" iadernoi RNK v sinteze antitel kletkami perevivnoi limfosarkomy krys.

The karyotype of the Ararat cochineal has been studied. The cochineal chromosomes are holokinetic, i.e. they have a diffuse centromeric activity; however, in some of them constrictions are detected. The constrictions are seen only in early stages of spiralization and are not detected in late metaphase. Sex determination in the cochineal takes place according to formula XX-X0. The female have two sex chromosomes being the longest pair in the set. The males are heterogametic having the X0-constitution. The meiosis is of a chiasmatic type. In the diakinesis bivalents are detected in the form of crosses or rings. Of different types of meiosis, the coccids possess a so called the Puto type, which s, according to preliminary evidences, very similar to the cochineal meiosis.

[Iron-containing blood proteins in poisoning by polyamide compounds]. / Zhelezosoderzhashchie belki krovi pri intoksikatsii poliamidnymi soedineniiami.

Chronic treatment (by means of inhalation) of rats with polyamide substances was accompanied by destabilization of erythrocyte membranes causing penetration of hemoglobin into blood serum. Electrophoresis of blood serum proteins in 7.5% polyacrylamide gel exhibited appearance of additional hemoglobin fractions electrophoretic mobility of which corresponded to the Ist and 4th fractions of erythrocyte hemoglobins. Estimation of hemoglobin composition in blood serum might be used for diagnostics of polyamide intoxication.