[Adrenocortical and thyroid systems of rats at the initial stage of nociceptive influence].

There are two phases in the initial period of formation of adrenocortical response to sharp nociceptive influence. The first phase (within 10-15 sec.) involves emergency mobilization of "basal" reserves of hormone active substances. It is characterized by reduction of corticoliberine activity in hypothalamic and extrahypothalamic structures of the rat brain with a parallel increase of corticotrophin concentration in plasma, devastation of corticosteroid reserves in adrenal glands; a decrease in the level of corticosteroids in blood against the background of accumulating hormone in bodies-targets. In the second phace: the phase of hypercompensation, the progressive increase of credit of the substances under study was quite obvious. The authentic changes in a level of aldosterone in adrenal glands and blood took place only in 2.5 minutes after the stress. The nociceptive influence was also biphasic when acting upon the reorganization of thyroid status number. However, unlike the initial adrenocortical response to stress in the first phase of thyroid reaction, the elevation of plasma thyroxine and tri-iodothyronine level was obvious. At the second stage, selective decrease in concentration of thyroxine to normal amounts occurred.

[The role of various classes of catecholamines in the central regulation of the hypothalamo-hypophyseo-adrenal cortex system]. / Rol' katekholaminov razlichnykh klassov v tsentral'noi reguliatsii gipotalamo-gipofizarno-adrenokortikal'noi sistemy.

Adrenaline, norepinephrine and dopamine were stereotaxically administered into mediobasal hypothalamus of rats. The data obtained revealed an activating catecholamine effect on the hypothalamo-hypophyseal-adrenal system (HHAS). The most obvious activating effect on the hormonal status of HHAS was characteristic of norepinephrine, less pronounced was the effect of "stress" doses of adrenaline and dopamine, the aforementioned effect was insignificant with dopamine in physiological concentration.

[Phases of the initial reaction of the sympatho-adrenal system to stress]. / Fazy pervichnoi reaktsii simpatiko-adrenalovoi sistemy na stress.

Changes in the content and ratio of catecholamines, their precursors and metabolites in canine blood and tissues during the initial period of stress have been studied. A sharp increase in tissue adrenaline (A) and dopamine (DA) and a decrease in tissue noradrenaline (NA); decline in blood A and rise in blood NA; inhibition of monoamine oxidase activity and a fall in metanephrine and normetanephrine blood and tissue level have been demonstrated in the first phase of reaction developing right after exposure to stress. A sharp synchronous rise in A, NA and DA and a parallel increase in their metabolic intensity towards oxidative deamination and O-methylation have been found in the second phase of reaction that develops in 60 sec. The first phase of the reaction has been designated as dissociation phase of sympathoadrenal secretory synthetic activity, and the second phase was termed the phase of synchronous system activation.

[Electrophysiological and catecholamine mechanisms of negative feedback in regulation of the hypothalamus by male sex glands]. / Elektrofiziologicheskie i katekholaminovye mekhanizymy otritsatel'noi obratnoi sviazi v gipotalamicheskoi reguliatsii muzhskimi polovymi zhelezami.

The immediate response on the part of the sympathoadrenal system (SAS) in mature male rats to testosterone propionate involves an increase in the content of dopamine and lowering of adrenaline and noradrenaline content in the hypothalamus, brain cortex, adrenals and peripheral organs, paralleled by an increase in the amplitude of evoked potentials and reduction in the frequency of induced impulse activity of arcuate neurons of the hypothalamus. This attests to the specificity of the associated response of the SAS and the hypothalamus-pituitary-gonadal system (HPGS) to hyperandrogenization and to the dopaminergic nature of the negative feed-back mechanism in the HPGS.

[Content of N-acetyl-L-asparate, N-acetyl-L-glutamate and N-acetyl-L-aspartyl-L-glutamate in the brain of mammals at increased oxygen tension]. / Soderzhanie N-atsetil-L-aspartata, N-atsetil-L-glutamata v mozge mlekopitaiushchikh pri povyshennom davlenii kisloroda.

The contents of N-acetyl-l-asparate and N-acetyl-l-glutamate, N-acetyl-l-aspartyl-l-glutamate were studied in the brain of rats of six age groups: newborns and on the 1st, 7th, 14th, and 30th day after birth. The amount of N-acetyl-l-asparate, N-acetyl-l-glutamate and peptide in the rat brain for 30 days of the postanal life is 8, 3.5 and 14.3 times as high, respectively. Under hyperoxic the amount of peptide, N-acetyl-l-asparate and N-acetyl-l-glutamate in the brain of rats of all the examined groups decreases especially in 14-, 21- and 30-day animals.