Prenatal stress selectively alters the reactivity of the hypothalamic-pituitary adrenal system in the female rat.

A study was made of the effects of prenatal stress on the reactivity of the hypothalamic-pituitary adrenal (HPA) axis in male and female offspring. Rat dams were subjected to noise and light stress on an unpredictable basis throughout pregnancy. At 28 days of age mRNA for POMC, proenkephalin and prodynorphin were measured in the hypothalamus of the offspring.

Effects of physical activity and other types of stress on catecholamine metabolism in various animal species.

The investigation of catecholamine (CA) metabolism in animals subjected to various types of stress (different pain syndromes; cranial trauma; immobilization; cooling) and physical exercise shows considerable similarity among species in the sequence of changes, leading from the activation to the depletion of the sympathoadrenal system. The changes caused by physical exercise tend to be more pronounced in individuals with a genetic predisposition to greater stress responses. Stress adaption, induced by special training or by long-duration exposure to hypoxia, can substantially prevent the changes caused by physical exercise.

[Effect of prednisolone on 3H-catecholamine synthesis in the adrenals of physically fatigued rats].

The effect of prednisolone on the synthesis of 3H-catecholamines by the adrenals of control and rats swimming for 8 hours was studied in experiments in vitro with the use of 3H-thyroxine as precursor. It was shown that in swimming rats, the synthesis of 3H-noradrenaline and 3H-adrenaline is inhibited by 25%, while the synthesis of 3H-dopamine remains unchanged. Addition of prednisolone to the incubation medium does not affect the rate of 3H-catecholamine synthesis by the adrenals of intact rats.

[Correlations between the indices of the state of the sympathetic-adrenal and of the hypophyseal-adrenal systems and the level of insulin in horses under various exposures].

The content of adrenaline, noradrenaline, ACTH, cortisol and insulin in the blood and excretion of catecholamines with urine were studied in horses after physical and emotional exposures. The highest degree of the sympathoadrenal system (SAS) and hypophysioadrenal system (HAS) activation followed by the insulin content decrease was observed after training. The known emotional exposure (the noise of hyppodrome) astivated both parts of SAS and HAS.

[Interaction of catecholamines and corticosteroids during the process of muscle fatigue].

After prolonged (8 hrs) swimming, the level of corticosteroids was reduced and the contents of aldosterone and DOC in the blood was increased in the rats. At incubation of these rats' adrenals in the L-thyrosine substratum the synthesis of adrenaline was reduced. Addition of hydrocortisone, prednisolone and corticosterone into the medium as well as in vivo administration of these increased the adrenaline synthesis in swimming rats and did not alter it in intact rats.

[Effect of glucocorticolids on catecholamine synthesis in the heart and adrenals of rats in the presence of physical fatigue].

The influence of the adrenal cortex hormones on the catecholamine synthesis in the adrenal glands and the heart of rats following prolonged swimming (8 hours) was studied. Catecholamine synthesis after the incubation of the adrenal glands and heart in the presence of L-tyrosine was sharply inhibited after swimming. Addition of hydrocortisone or prednisolone in vitro (50 microgram per sample) and also administration of these hormones in vivo (50 mg/kg intramuscularly, 3 hours before decapitation) increased catecholamine synthesis in the adrenal glands of swimming, but not of intact rats.

[Catecholamines, their precursors and metabolites in human fatigue after exertion].

Alterations in metabolism of catecholamines were studied in sportsmen after development of acute fatigue as a result of the test physical loading. Three types of the alterations were characterized on the basis of differences in excretion with urine of free and sulphate-bound adrenaline, noradrenaline, of their precursors DOPA and dopamine as well as acid metabolites (vanillyl mandelic acid). The first type of the alterations in catecholamines metabolism comprized the cases, when excretion of catecholamines, their precursors and metabolites did not increase; this appears to relate to the partial exhaustion of hormones and peripheric mediators of sympathoadrenal system.

[L-DOPA test for evaluating in vivo catecholamine biosynthesis in normal persons and persons with different diseases].

Administration of 1-DOPA into healthy persons increased its excretion with urine and elevated the adrenaline secretion. The increase of catecholamines excretion was not observed in aged patients with hypertension; the data obtained suggest that the synthesis of catecholamines with utilization of DOPA was inhibited. In patients with ulcerous disease excretion of 1-DOPA was not increased after its administration, but secretion of catecholamines was decreased during the day time.

[Influence of preliminary adaptation to altitude hypoxia on catecholamine concentration in the hypothalamus, adrenals and heart under great physical stress].

Rats were subjected to adaptation to heigth hypoxia in an altitude chamber at the "heigth" 6 km within 7 weeks for 6 hrs a day. Concentration of noradrenaline and adrenaline was normal in hypothalamus; in myocardium content of noradrenaline was also normal but content of adrenaline was slightly decreased; in adrenal glands content of both hormones was distinctly increased. High physical activity (7 hrs swimming) did not alter content of noradrenaline in hypothalamus and adrenal glands of unadaptated rats but decreased 3-fold the content in myocardium.

[Catecholamine metabolism during adaptation to muscular activity].

In rats, an increased O-methylation in the brain, heart, liver, and in the m. gastrocnemius as well as an increased intensity of oxidative desamination in the liver were revealed after muscular training and administration of retabolile. After additional 70-min swimming, in intact rats the MAO activity was raised in the liver, and the intensity of O-methylation - in the muscle and the heart.

[Mechanisms of catecholamine synthesis disorders in the adrenals of rats subjected to physical fatigue].

There was a depression of transformation of noradrenaline, DOPA and thyrosine added in vitro, into catecholamines in the adrenal glands of rats after swimming for a period of 8 hours. This permitted to suppose a depression of the activity of phenylethanolamine-N-methyl-transpherase, DOPA-decarboxylase, and, possibly, of tyrosine hydroxylase under these conditions. After the end of swimming, in the presence of 1-tyrosine, there is at first an activation of noradrenaline synthesis, and then there occurs a gradual normalization (on the 7th day) of adrenaline formation.