Caspase-3 activity in papillary thyroid carcinomas.

AIM: The aim of this work was to assess caspase-3 activity in the tissue of papillary thyroid carcinomas of patients and analyze the peculiarities of changes in this activity depending upon a number of pathomorphological and clinical features of tumoral process. METHODS: Caspase-3 activity was determined by spectrophotometry with regard to acetyl-asp-glu-val-asp-paranitroanilide. RESULTS: At initial stages of tumor development, in the absence of metastases to lymph nodes, blood and lymphatic vessel invasion by tumor cells, extrathyroid spreading of tumor, sclerotic and fibrous changes in tumor stroma, and in the presence of tumor capsule, caspase-3 activity in papillary carcinoma tissue was higher compared to unchanged thyroid tissue of normofollicular structure. In case of a more aggressive behaviour of tumor, enzyme activity in carcinoma tissue did not differ significantly or (in case of extrathyroid spreading of tumor) was decreased compared to that in extratumoral tissue. In combination, this was expressed by a progressive decrease in caspase-3 activity in tumor tissue with increasing T category. Сaspase 3 activity was found to be much higher in the tissue of papillary carcinomas of follicular-papillary structure and lower in the tissue of tumors of mixed structure with solid areas, compared to that in the tissue of papillary carcinomas of typical papillary structure. CONCLUSIONS: The data obtainеd in assessing caspase-3 activity suggest that the intensity of spontaneous apoptosis of human papillary thyroid carcinoma cells depends upon the stage and aggressiveness of tumoral process.

[DNA fragmentation rate in human thyroid tissue and carcinomas and its change under the influence of a-tocopherol and iodine ions in vitro].

The rate of DNA fragmentation was studied in intact thyroid tissue and thyroid carcinoma tissue. The determination of low molecular-weight DNA concentrations and the electrophoretic analysis of DNA isolated from the thyroid tissues and tumors, followed by the calculation of the content of oligonucleosome fractions, indicated a drastic reduction in the DNA fragmentation rate in papillary carcinomas and no its significant changes in follicular carcinomas. In the intact thyroid tissue, α-tocopherol and potassium iodide at a concentration of 10-7 M inhibited the rate of stimulated DNA fragmentation in vitro. The agents showed no effect in the papillary carcinoma tissue and their effect was similar in the follicular carcinoma tissue, but it was less pronounced in intact thyroid tissue.

[Sex characteristics of neuroendocrine effects of prenatal exposure to exogenous glucocorticoids].

The effects of hydrocortisone acetate treatment of rats during the last gestational week on neurochemical and morphological characteristics of the brain in early postnatal and mature offspring were studied. Disappearance of sexual differences both in aromatase and 5alpha-reductase activities and noradrenaline concentration in the preoptic area in 10-day old rats was found. Meanwhile a sexual dimorphism in serotonin metabolism emerged. In adult offspring, the prenatal exposure to glucocorticoids resulted in disappearance of sexual differences in neurocytes' nuclei volume in medial preoptic and suprachiasmatic nuclei. The adrenocortical reaction to noradrenaline infusion to the 3rd brain ventricle was absent in the experimental males and intensified in females. In males, adrenocortical reaction to restraint decreased while post-stress changes in hypothalamic noradrenaline concentration and hippocampal glutamate decarboxylase activity were not observed. In the similar experiments in females both the augmentation of adrenocortical reaction and inhibition of GABA-ergic system were revealed. The results obtained indicate the modifying effect of prenatal exposure to glucocorticoids on sexual dimorphism of neuroendocrine system.

Specific GABA binding in the adrenals and blood corticosteroid levels in stress in intact rats and rats with changes in the functional activity of the hypothalamo-pituitary-adrenal system.

Thirty minutes of swimming led to decreases in the specific binding of GABA to adrenal plasma membranes in intact rats, but not in rats repeatedly given hydrocortisone to inhibit the baseline activity of the hypothalamic-pituitary-adrenal cortex system, where the level of reception of this amino acid was significantly greater than in controls. Pre-stress administration of baclofen and gamma-L-aminobutyryltaurine had no effect on specific GABA binding, even though these agents affected blood corticosterone concentrations.

Geriatric men at altitude: hypoxic ventilatory sensitivity and blood dopamine changes.

BACKGROUND: Short-term exposure to high-altitude hypoxia increases hypoxic ventilatory sensitivity (HVS) in healthy humans. Dopamine (DA) is the implicated neurotransmitter in carotid body (CB) chemoreceptor response, and the microenvironmental conditions in CB tissue are comparable to blood. Continuous DA infusion affected ventilation in animals and humans. Age-related oscillations in blood DA levels may influence peripheral chemoreflexes. OBJECTIVE: Hypoxic ventilatory responses (HVR) relative to blood DA concentration and its precursor, dihydroxyphenylalanine (DOPA) was measured in young and elderly men during short-term altitude adaptation. METHODS: Nine elderly climbers (group 1:61+/-1.4 years) and 7 young healthy subjects (group 2: 23+/-2 years) were tested at sea level on day 0, on day 3 after passive transport to 2,200 m, and on day 14 after climbing to 4,200 and 5,642 m. RESULTS: Sea level HVR in group 1 was 47% lower than in group 2, accompanied by higher blood DOPA (300%) and DA (37%) content. Initial DA and DOPA concentrations showed a negative correlation with initial HVR but a positive correlation with age. Passive transport to middle altitude (2,200 m) increased HVS, doubling HVR slopes in groups 1 and 2 and producing increased maximum expired minute ventilation during isocapnic rebreathing (29 and 28%, respectively). Day 3 2,200-meter blood DOPA content decreased by 22% in group 1 and increased by 300% in group 2. DA increased in both groups. CONCLUSION: The relationship between HVR and the reciprocal DA and DOPA values seen in both groups is associated with age, producing decreased DA receptor sensitivity and enhanced DA reuptake during adaptation to high altitude.

Human hypoxic ventilatory response with blood dopamine content under intermittent hypoxic training.

Adaptation to intermittent hypoxia can enhance a hypoxic ventilatory response (HVR) in healthy humans. Naturally occurring oscillations in blood dopamine (DA) level may modulate these responses. We have measured ventilatory response to hypoxia relative to blood DA concentration and its precursor DOPA before and after a 2-week course of intermittent hypoxic training (IHT). Eighteen healthy male subjects (mean 22.8+/-2.1 years old) participated in the study. HVRs to isocapnic, progressive, hypoxic rebreathing were recorded and analyzed using piecewise linear approximation. Rebreathing lasted for 5-6 min until inspired O2 reached 8 to 7%. IHT consisted of three identical daily rebreathing sessions separated by 5-min breaks for 14 consecutive days. Before and after the 2-week course of IHT, blood was sampled from the antecubital vein to measure DA and DOPA content. The investigation associated pretraining high blood DA and DOPA values with low HVR (r = -0.66 and -0.75, respectively), elevated tidal volume (r = 0.58 and 0.37) and vital capacity (r = 0.69 and 0.58), and reduced respiratory frequency (r = -0.89 and -0.82). IHT produced no significant change in ventilatory responses to mild hypoxic challenge (Peto2 from 110 to 70-80 mm Hg; 1 mm Hg = 133.3 Pa) but elicited a 96% increase in ventilatory response to severe hypoxia (from 70-80 to 45 mm Hg). Changes in HVRs were not accompanied by statistically significant shifts in blood DA content (24% change), although a twofold increase in DOPA concentration was observed. Individual subject's changes in DA and DOPA content were not correlated with HVR changes when these two parameters were evaluated in relation to the IHT. We hypothesize that DA flowing to the carotid body through the blood may provoke DA autoreceptor-mediated inhibition of endogenous DA synthesis-release, as shown in our baseline data.

[Blood level of gamma-aminobutyric acid--"peripheral index" of the state of central neuromediator system]. / Soderzhanie gamma-aminomaslianoi kisloty v krovi--"perifericheskii indikator" sostoianiia tsentral'noi neiromediatornoi sistemy.

The review summarized data on contents of the main inhibitory neurotransmitter of the central nervous system: gamma-aminobutyric acid (GABA) in blood of normal animal and humans, in blood of different animal species under experimental effects and modelling of pathological states, as well as in human blood in the presence nervous and endocrine diseases. Determination of GABA concentration in blood, taking into account the accessibility of study object, absence of significant sex, age, seasonal, diurnal fluctuations, as well as stability of amino acid level during the laboratory assay procedure, may be useful for the study of central neuromediator mechanisms, and allows, using representative samples and corresponding groups of comparison, to obtain data on disturbances of functional state of the GABAergic system under conditions of brain pathology.

[Gamma-aminobutyric acid content and activity of the enzyme synthesizing it in blood plasma of children exposed to ionizing radiation as a result of the accident at the Chernobyl nuclear power plant]. / Soderzhanie gammaaminomaslianoi kisloty i aktivnost' fermenta ee sinteza v plazme krovi detei, podvergavshikhsia vozdeistviiu ioniziruiushchei radiatsii vsledstvie avarii na Chernobyl'skoi AES.

Marked individual fluctuations in blood levels of GABA and GDC revealed in 35 to 50% of adolescents exposed to ionizing radiation several years before indicate the presence of an imbalance in the GABA-ergic system. These children (with GABA-ergic system disturbances) represent a group at risk of developing remote effects of radiation exposure presenting as disturbed rhythms and terms of sexual maturation, of growth, thyroid and adrenal abnormalities, and they should be regularly checked up.

[Kinetic parameters of GABA receptor binding by rat adenohypophyseal membranes under conditions of modelling various corticosteroid and ACTH levels in the body]. / Kineticheskie parametry retseptornogo sviazyvaniia GAMK membranami adenogipofiza krys v usloviiakh modelirovaniia razlichnykh urovnei kortikosteroidov i AKTG v organizme.

Kinetic parameters of 14C-GABA specific binding by rat adenohypophyseal plasma membranes were studied in experiments on modelling various corticosteroid and ACTH levels in animal body. A single hydrocortisone injection did not change K alpha for high- and low-affinity GABA receptors, the number of the former (Bmax) increasing in this case. Repeated hydrocortisone injections were associated with K alpha reduction for high-affinity GABA receptors and a noticeable increase of K alpha for low-affinity receptors, with their number reducing. ACTH injection did not change the kinetic parameters of GABA binding with receptors. The number of high-affinity GABA receptors and their affinity reduced after removal of adrenals whereas the number of low-affinity receptors in this case was increasing. A single hydrocortisone injection to adrenalectomized rats had a normalizing effect on adenohypophyseal GABA receptors. Analysis of the results and changes in blood hormonal levels indicated that affinity changes in high-affinity receptors and changed number of low-affinity adenohypophyseal GABA receptors correlated with changes in ACTH and hydrocortisone changes.

[The effect of GABA-ergic preparations on the function of the hypothalamo-hypophyseal-adrenal system in patients with Itsenko-Cushing disease]. / Vliianie GAMK-ergicheskikh preparatov na funktsional'noe sostoianie gipotalamo-gipofizarno-nadpochechnikovoi sistemy u bol'nykh bolezn'iu Itsenko--Kushinga.

The effect of aminalon, baclofen and valproic acid on the levels of ACTH and cortisol was investigated in 58 patients with Itsenko-Cushing disease. The effect of GABAergic drugs showed correlation with the basal level of blood GABA: with aminalon and valproic acid the effect was observed only in patients with a low level of GABA, with baclofen--in patients with a high level of GABA there was found a decrease in the level of ACTH, associated with a high level of cortisol.

[Formation of gamma-aminobutyric acid from glutamate and putrescine in rat hypothalamic and hippocampal synaptosomes and regulation of these processes by glucocorticoids]. / Obrazovanie gamma-aminomaslianoi kisloty iz glutamata i putrestsina v sinaptosomakh gipotalamusa i gippokampa krys i reguliatsiia étikh protsessov gliukokortikoidami.

It has been shown that single or multiple hydrocortisone and ACTH administrations to intact rats increased GABA content and its synthesis from glutamate and putrescine in synaptosomes of hypothalamus. The letter content was increased by single hormonal administration while multiple hormonal administration and adrenalectomy decreased it. Ornithine decarboxylase activity was increased by single hydrocortisone administration to intact animals, following adrenalectomy, and it was decreased by single hormonal administration to adrenalectomized rats. GABA synthesis in synaptosomes of hippocampus from putrescine was increased by single hydrocortisone and multiple hormonal administrations. GABA content was increased by multiple administration of both hormones and was decreased by adrenalectomy. Putrescine level was decreased by multiple hydrocortisone administration to intact and single administration to adrenalectomized rats; ornithine decarboxylase activity was decreased by multiple administration of both hormones.

[The gamma-aminobutyric acid content of the blood plasma in patients with Itsenko-Cushing disease and its dependence on clinical and hormonal indices]. / Soderzhanie gamma-aminomaslianoi kisloty v plazme krovi bol'nykh bolezn'iu Itsenko--Kushinga i ego zavisimost' ot klinicheskikh i gormonal'nykh pokazatelei.

The content of GABA was measured in blood plasma of 111 patients suffering from Itsenko-Cushing disease. In untreated females, the blood GABA content was noticeably lowered; during treatment it increased, reaching normal, on the average, in patients with a history of total adrenalectomy. The changes in the blood GABA content in male patients were marked to a less degree. In the persons with a history of total adrenalectomy the GABA content turned out higher than normal. The blood GABA content in patients was dependent on the age and disease standing. In males experiencing disease exacerbation, it was appreciably reduced. As compared to females, the degree of a negative correlation between the blood content of GABA and ACTH (or cortisol) in males was more pronounced. The correlation between the excretion of 17-HCS with urine and GABA blood content in men and women was reverse. Women manifested a positive correlation between the excretion of 17-HCS with urine and blood GABA content, whereas men between arterial pressure and blood GABA. The problem of potential disorders of the GABAergic brain system in patients afflicted with Itsenko-Cushing disease is under discussion.

[Specific binding of H3-GABA by synaptic membranes of hypothalamus and hippocampus in rats after adrenalectomy and administration of hydrocortisone and corticosterone]. / Spetsificheskoe sviazyvanie H3-gamma-aminomaslianoi kisloty sinapticheskimi membranami gipotalamusa i gippokampa krys posle adrenaléktomii i vvedeniia gidrokortizona i kortikotropina.

It has been shown that single hydrocortisone administration increased 3H-GABA binding by hypothalamic synaptic membranes. ACTH administration enhanced binding in both studied brain structures. Multiple hydrocortisone administration did not effect 3H-GABA binding by hypothalamic and hippocampal membranes, while multiple ACTH administration caused the decrease in mediator binding by hypothalamic membranes and increased its level in hippocampal membranes. Adrenalectomy did not change 3H-gaba binding and single hydrocortisone administration to adrenalectomized rats increased 3H-GABA binding only by hypothalamic synaptic membranes.

[Polyamines in the hypothalamus and hippocampus after the changes in corticosteroid levels in rats]. / Poliaminy gipotalamusa i gippokampa pri izmenenii urovnia kortikosteroidov v organizme krys.

Adrenalectomy as well as single or multiple hydrocortisone and ACTH administration have been studied for their effect on putrescine, spermidine and spermine contents, ornithine decarboxylase and S-adenosyl-+methionine decarboxylase activities in the rat hypothalamic and hippocampal tissues and fraction of nervous endings. The data obtained prove complicated character of changes in polyamine metabolism in the studied structures when glucocorticoid level is disturbed. Hormone action is characterized by regional and intracellular specificity and depends upon the ratio of administration and the initial hormonal background of the organism. The significance of these changes for feedback regulation of ACTH secretion and metabolism of GABA is discussed.

[Hormonal control of metabolism of gamma-aminobutyric acid in the rat hypothalamus and hippocampus]. / Gormonal'nyi kontrol' obmena gamma-aminomaslianoi kisloty v gipotalamuse i gippokampe krys.

It has been established that hydrocortisone administration increased the amount of total, free, bound and synaptosomal GABA in the hypothalamus, glutamate decarboxylase activity in the homogenate and synaptosomes and time of the mediator turnover. ACTH administration increased the GABA content and glutamate decarboxylase activity in synaptosomes. The total amino acid content and time of its turnover got higher only with single hormone administration. In the hippocamp hydrocortisone administration increased the total and free GABA contents, its turnover time, glutamate decarboxylase activity in the homogenate and decreased GABA-aminotransferase activity in the homogenate and synaptosomes. The GABA level in synaptosomes grew only with multiple hormone administration. Single administration of ACTH decreased the total GABA content, glutamate decarboxylase activity in the homogenate, while its multiple administration increased the GABA level in synaptosomes followed by a decrease of GABA-aminotransferase activity in the homogenate and synaptosomes. The GABA turnover time fell with single hormone administration and grew with the multiple one. Adrenalectomy induced no changes in the GABA content and activity of its metabolism enzymes in the hypothalamus, however the bound GABA level decreased, while the turnover time increased. In the hippocamp adrenalectomy decreased total, free and synaptosomal GABA contents, glutamate decarboxylase activity in a homogenate and turnover time. Subsequent hydrocortisone administration only partly normalized the revealed changes of the GABA metabolism in the brain structures under adrenalectomy.

[Gamma-aminobutyric acid level and glutamate decarboxylase activity in the plasma of healthy persons]. / Soderzhanie gamma-aminomaslianoi kisloty i aktivnost' glutamatdekarboksilazy v plazme krovi zdorovykh liudei.

Content of gamma-aminobutyric acid in blood plasma of healthy persons did not depend on sex and age and of women--on the phase of menstrual cycle. Activity of glutamate decarboxylase was higher 1.5-fold in blood plasma of women as compared with that of men values; a decrease in the enzymatic activity was observed in men after 30 years old and in women--after 40 years old. Activity of glutamate decarboxylase was higher in blood plasma of young and middle age women during the lutein phase of menstrual cycle as compared with the follicular phase, while this ratio reversed its direction in blood plasma of older women as a result of distinct decrease in the enzymatic activity during the lutein phase of the cycle.

[Uptake of gamma-aminobutyric acid and glutamate decarboxylase activity in synaptosomes of various regions of the brain of rats in adrenalectomy and in subsequent hydrocortisone administration]. / Zakhvat gamma-aminomaslianoi kisloty i aktivnost' glutamatdekarboksilazy v sinaptosomakh razlichnykh otdelov mozga krys pri adrenaléktomii i posleduiushchem vvedenii gidrokortizona.

The adrenalectomy in rats followed by a single hydrocortisone administration had no influence on the glutamate decarboxylase activity and maximum rate of [3H] GABA uptake by synaptosomes of hypothalamus, hippocampus and cerebral hemispheres. Km of [3H] GABA uptake by synaptosomes in the above mentioned brain regions under adrenalectomy decreases sharply; hydrocortisone administration increases Km of mediator uptake by hippocampus synaptosomes, and hydrocortisone in vitro increases Km of [3H] GABA uptake by hypothalamus synaptosomes.

[Glutamate decarboxylase activity in the hypophysis after changes in corticotropin levels in rats]. / Aktivnost' glutamatdekarboksilazy v gipofize pri izmenenii urovnia kortikotropina v organizme u krys.

It was shown that glutamate decarboxylase is present in the whole hypophyses and its anterior pituitary lobe of experimental rats. Single and repeated hydrocortisone- and/or multiple desoxycorticosterone injections to intact rats led to a decrease in the hypophyseal glutamate decarboxylase activity. The enzyme activity remained unchanged after cyproheptadine use and lowered following nacom administration (the drugs, blocking corticotropin secretion). Adrenalectomy induced a sharp fall of the glutamate decarboxylase activity in the rat hypophyses. The enzyme activity returned completely to normal after cyproheptadine use and was partially stabilized following a single hydrocortisone injection in the hypophyses of adrenalectomized rats.