[The action of heart factor H1 on the synthesis and uptake of dopamine and noradrenaline in the rat heart]. / Deistvie serdechnogo faktora H1 na sintez i zakhvat dofamina i noradrenalina v serdtse krys.

The action of heart factor H1 on the synthesis and uptake of dopamine and noradrenaline in the atria and ventricle of rat heart and also the participation of Ca2+ and ATP in the action of H1 was studied. It has been shown, that H1 in the doses of 2 and 20 mU/ml increases the synthesis of 14C-dopamine in the atria by 43-44% and does not effect on this process in ventricle. The synthesis of 14C-noradrenaline in the atria increases in the presence of H1 (2-20 mU/ml) by 64 and 40%. A dose-dependent decrease of 3H-dopamine uptake in the atria under the influence of H1 was observed. The uptake of 3H-noradrenaline in the ventricle as well as in the atria is not altered in the presence of H1. In the absence of Ca2+ H1 in not caused any stimulation of 14C-dopamine and 14C-noradrenaline synthesis in the atria. But in the absence of both Ca2+ and ATP the stimulating effect of H1 on the synthesis of 14C-noradrenaline is maintained.

A fraction enriched in dendrodendritic synaptosomes isolated from rat olfactory bulb: morphology and transmitter release.

A fraction enriched in dendro-dendritic synaptosomes was isolated from rat olfactory bulb by a rapid method. Synaptosomes preserved their ultrastructure and showed configurational changes in relation to incubation in physiological ion medium as described earlier in the case of cortical synaptosomes. Dendro-dendritic synaptosomes were larger and contained more mitochondria than cortical synaptosomes. Doublets of terminals synapsing with each other were frequently seen and each terminal contained synaptic vesicles. Oxygen consumption of dendro-dendritic synaptosomes was decreased by ouabain and increased by 2,4-dinitrophenol. High-potassium medium evoked a considerable release of GABA and dopamine but not of noradrenaline or serotonin in accordance with histochemical published data.

[Biogenic amine content of brain sections, blood and adrenals of rabbits exposed to vibration and noise]. / Soderzhanie biogennykh aminov v nekotorykh otdelakh mozga, krovi i nadpochechnikakh krolikov pri vozdeistvii vibratsii i shuma.

Phasic changes of biogenic amines were revealed in brain structures after isolated action of vibration; 15-min vibration increased the content of catecholamines in the hypothalamus and decreased the content of serotonin. 30-min vibration decreased the amount of biogenic amines in the hypothalamus and the cortex. Vibration of a longer duration (1 hr) increased the amount of catecholamines in the brain. After 2-hr vibration the content of catecholamines returned to the control level but the concentration of serotonin still remained above it. Combined action of vibration and noise (2 hrs) decreased the content of catecholamines and increased the amount of serotonin in cerebral structures. Dopamine and serotonin tended to decrease in the blood and adrenals whereas in the urine their amount increased. Multiple combined action of vibration and noise induced the most obvious changes.

Comparative studies of fresh and postmortem isolated rat cortical synaptosomes: uptake and potassium-evoked release of gamma-aminobutyric acid.

Synaptosomal fractions were isolated from rat cerebral cortex immediately after decapitation and after 2 h and 4 h postmortem storage at room temperature. Uptake and release of [3H]GABA was compared between fresh and postmortem synaptosomal fractions. The results suggest that after a 2 h postmortem storage these functions are still comparable to those observed in fresh preparations, while a 4 h period of storage decreases them by about 50%. The present data are consistent with our previous findings that the 2 h postmortem fractions are comparable to freshly isolated fractions with respect to coupled respiration, potassium accumulation and capability of specific configurational changes.

[The effect of exogenous concentration of chlorine and calcium ions on GABA and bicuculline action on the K+ -induced release of H3-noradrenaline from synaptosomes]. / Vliianie naruzhnoi kontsentratsii ionov khlora i kal'tsiia na deistvie GAMK i bikukullina v K+ -vyzvannom vysvobozhdenii noradrenalina-H3 iz sinaptosom.

Effects of GABA (10(-3) M) and its antagonist bicuculline on K+-evoked release of H3-NA were studied in synaptosomes of rat mesodiencephalic region in the absence of Cl-, Ca2+ ions and in the presence of Ca2+ antagonist Mn2+ ions. K+-evoked release of H3--NA activated by GABA did not change in a Cl--free medium. Bicuculline blocked the activating effect of GABA. Some noticeable activation of K+-evoked release of H3--NA was observed in Cl- and Ca++--free medium. GABA, however, inhibited this process. Under these conditions, K+-evoked release of H3--NA did not occur in the presence of bicuculline. Mn2+ ions blocked GABA- and bicuculline--activated K+--evoked release of H3--NA. Taking into account the opposite effect of GABA on K+-evoked release of H3--NA depending on ionic changes in incubation media, the possibility of Cl- and Ca2+ ions participation in the GABA effect is considered.

[Effect of gamma-aminobutyric acid on K+-induced and Ca++-dependent release of H3-noradrenaline from synaptosomes of the meso-diencephalic region of the rat brain]. / Deisvie gamma-aminomaslianoi kisloty na K+-vyzvannoe Ca++-zavisimoe vysvobozhdenie noradrenalina-H3 iz sinaptosoma mezo-diéntsefal'noi oblasti mozga krys.

GABA exerted no effect on H3-NA release from synaptosomes in the presence of 20 mM K+ whereas it considerably reduced the release of H3--NA evoked by 40 mM K+ ions. The omission of Ca++ ions from the superfusion fluid reduced by H3-NA release; on the other hand, GABA in this condition enhanced considerably the release of H3-NA thus exhibiting Ca++-like effect. Thus in the absence of Ca++ or in the presence of its low (1 mM) concentrations the effects of GABA on the H3--NA release from the synaptosomes was reversed.

[Effect of GABA on the synthesis, uptake and release of noradrenaline-H3 from brain slices]. / Deistvie GAMK na sintez, zakhvat i vykhod noradrenalina-H3 iz mozgovykh srezov.

The data obtained showed that GABA exerted no effect on the synthesis and putake of H3-NE while increasing its loss from slices preincubated for 5 min before incubation for 30 min with H3-NE for uptake. When slices were preincubated for 30 before the addition of H3-NE the effect of GABA on NE content in the slices was reversed. A similar reversal of the GABA effect occurred when varying the preincubation period of slices subjected to prolonged electrical stimulation. The uptake and release of H3-NE were not affected by the duration of the preincubation period. The reversal of the GABA effect on H3-NE did not correlate with the depletion of endogenous stores of NE and may be due to the changes in the ionic composition of slices in the course of the prolonged incubation.

[Role of Na and Cl ions in retaining noradrenaline and serotonin in the meso-diencephalic region of the rat brain and in the action of gamma-aminobutyric acid on that process]. / Znachenie ionov Na i Cl v uderzhivanii noradrenalina i serotonina v mezo-díentsefalicheskoi oblasti mozga krys i v deistvii gamma-aminomaslianoi kisloty na étot

It has been previously reported from this laboratory that CABA affects the retention of norepinephrine (NE) and serotonin (5-HT) in rat brain tissue [2, 3, 4]. The addition of GABA (100 mug/ml) to the incubation medium enhances significantly the loss of NE from slices while the loss of 5-HT is, on the contrary, significantly smaller than that observed from slices incubated parallely for the same period. It has also been shown that this effect is observed only in a balanced ionic medium [1]. With the purpose of finding out the importance of Na+ and Cl- ions in the storage of monoamines and in the effect of GABA on this process in the present report we studied the effect of GABA on the loss of NE and 5-HT from slices of rat mesodiencephalic region incubated in media free of Na+ and Cl- ions. The effect of GABA on Na+, K+-ATP-ase activity, an enzyme involved in the active transport of monoamines, was also studied. The results obtained indicate that loss of both NE and 5-HT from slices was significantly enhanced in a Na+-free medium and that on addition of GABA (100 mug/ml) to such a medium no significant changes GABA were noted. In a Cl--free medium loss of NE from slices was enhanced while that of 5-HT was not affected. When GABA was added to such a medium the usual pattern so far observed in our experiments, i.e. an enhancement in the loss of NE from slices, was found to be reversed. The pronounced decrease of NE observed in a Cl--free medium was found to be partially checked by the addition of GABA, the difference observed being statistically significant. Thus, in a Cl--free medium GABA seems to display an effect on NE storage opposite to that observed in a normal medium. Incubation in a Cl--free medium did not induce any noticeable change in the retention of 5-HT in slices. However, when GABA was added to slices incubated in a Cl--free medium, it no more displayed its usual effect, i.e. it did not inhibit the loss of 5-HT from slices. Under the given experimental conditions, GABA added to a balanced ionic medium did not effect Na+,K+-ATP-ase activity. This is in good agreement with previous results from our laboratory [4] where GABA was shown to have no effect on the uptake of NE and 5-HT by slices of rat brain, an active, carrier-mediated process coupled with Na+,K+-ATP-ase activity.