CHANGES IN ARTERIOLE REACTIVITY TO NORADRENALINE UNDER CONDITIONS OF HYPERHOMOCYSTEINEMIA.

The aim of the research was the experimental study of one of the possible mechanisms performing contractile activity of arterioles in hyperhomocysteinemic animals. Moderate hyperhomocysteinemia was induced in male rats (120-160 g., n=12) by adding L-methionine to the drinking water during 4 weeks.

Effect of pyroglutamylasparagine amide on plastic characteristics of synaptic transmission in the hippocampus.

Preincubation of rat hippocampal slices with 0.05-0.5 microM pyroglutamylasparagine amide improved characteristics of long-term potentiation of focal responses in the synaptic system of Schaffer collaterals-CA1 field pyramids facilitating LTP development and increasing its amplitude and duration.

[Preservation of plastic properties of synaptic transmission in long-lasting hippocampal slices under the effects of a peptide analog of piracetam, L-pGlu-D-Ala-NH2].

The tetanic stimulation of the Schaffer collaterals (SC) in rat hippocamp slices after 6 hrs in vitro conditions did not produce long-term potentiation (LTP) of the field response amplitude in the CA1 pyramidal cell layer. In contrast, LTP after the late tetanization was well preserved in the slices that were perfused for 20 minutes with 0.5 mkM L-pGlu-D-Ala-NH2 (PGAA) after 4-4.

[Effects of polymethylene derivatives of 4-aminopyridine on functional properties of hippocampal neurons].

The effects of amiridin (9-amino-2,3,5,6,7,8-hexahydro-IH-cyclopenta(b) quinoline) and tacrine (1,2,3,4-tetrahydro-9-aminoacridine) on Schaffer collaterals--CAI field potentials were compared in rat hippocampal slice preparations. Similar dose-dependent increase in pop-spike amplitude was observed during slice perfusion with low concentrations of amiridin (5-50 microM) or tacrine (0.5-10 microM).