Nine months in space: effects on human autonomic cardiovascular regulation.

We studied three Russian cosmonauts to better understand how long-term exposure to microgravity affects autonomic cardiovascular control. We recorded the electrocardiogram, finger photoplethysmographic pressure, and respiratory flow before, during, and after two 9-mo missions to the Russian space station Mir. Measurements were made during four modes of breathing: 1) uncontrolled spontaneous breathing; 2) stepwise breathing at six different frequencies; 3) fixed-frequency breathing; and 4) random-frequency breathing. R wave-to-R wave (R-R) interval standard deviations decreased in all and respiratory frequency R-R interval spectral power decreased in two cosmonauts in space. Two weeks after the cosmonauts returned to Earth, R-R interval spectral power was decreased, and systolic pressure spectral power was increased in all. The transfer function between systolic pressures and R-R intervals was reduced in-flight, was reduced further the day after landing, and had not returned to preflight levels by 14 days after landing. Our results suggest that long-duration spaceflight reduces vagal-cardiac nerve traffic and decreases vagal baroreflex gain and that these changes may persist as long as 2 wk after return to Earth.     

Early effects of the influence of ionizing radiation in relatively small doses on the neuromediator systems responding to the central regulation of the hypothalamo-pituitary-adrenal cortex system

In experiments with mature Wistar male rats changes of mediator interrelations in different brain parts, responsible for the central regulation of the hypothalamo-pituitary-adrenocortical system, were detected at early times after whole-body X-irradiation with a dose of 12.9 mC/kg. These changes represent one of the major mechanisms leading, at later times after irradiation, to the development of syndromes related to diencephalic disturbances.     

自主神经系统参与低氧下的免疫调节作用

目的：探讨低氧条件下自主祖辈 经系统对大鼠脾淋巴细胞转化的调节作用。方法：检测减压低氧下外周血中神经递质与脾淋巴细胞转化。结果：大鼠5km低氧暴露24h,脾淋巴细胞对丝裂原反应性下降,外周交感神经损毁后则可阻断低氧对此的抑制作用;小鼠于真空瓶中0.07MPa缺氧10min血浆中去甲肾上腺素（NE）与肾上腺素（E）均明显升高;大鼠5km低氧24h,血浆中乙酰胆碱水平下降;体外培养的大鼠脾淋邓细胞中加入不同浓度的乙酰胆碱,胸腺嘧啶核苷掺入作用呈浓度依赖性增加。结论：以上结果提示自主神经系统参与低氧下的免疫调节,交感神经系统有免疫抑制作用,副交感神经起免疫增强作用。     

Autophagic processes in plants: mechanisms, regulation and function

Large numbers of publications investigating the molecular details, the regulation and the physiological roles of autophagic processes have appeared over the last few years, dealing with animals, plants and unicellular eukaryotic organisms. This strong interest is caused by the fact that autophagic processes are ubiquitous in eukaryotic organisms. They are involved in the adaptation of organisms to their environment and to stressful conditions, thereby contributing to cell and organism survival and longevity. This review article aims to describe the discovery of autophagy, the molecular details of this complex process, its regulation, and its specific functions in plants.     

Corticotropin-releasing factor receptor antagonist: effects on the autonomic nervous system and cardiovascular function

The corticotropin-releasing factor (CRF) receptor antagonist, alpha-helical [Glu27]-corticotropin-releasing factor 9-41 (CRF 9-41) has been assessed for its ability to modify plasma concentrations of epinephrine and norepinephrine, mean arterial pressure (MAP) and heart rate (HR). Basal concentrations of epinephrine and norepinephrine were not altered by lateral ventricular (icv) administration of CRF 9-41. However, this CRF antagonist, given icv, attenuated the rise of plasma epinephrine following 30% hemorrhage and insulin-induced hypoglycemia. CRF 9-41 did not alter the increased plasma concentrations of epinephrine or norepinephrine following icv administration of bombesin. Icv administration of CRF 9-41 blunted CRF-induced elevation of MAP and HR in normal animals. However, this CRF antagonist did not modify the MAP or HR in spontaneously hypertensive rats. Similarly, this CRF antagonist administered to Sprague-Dawley rats neither prevented the rise of MAP or HR following electrical stimulation of the central nucleus of the amygdala, nor did it affect nitroprusside-induced hypotension and tachycardia.     

Thyrotropin releasing hormone: autonomic effects upon cardiorespiratory function in endotoxic shock

These studies define potential sites and mechanisms by which thyrotropin releasing hormone (TRH) stimulates cardiorespiratory function in normotensive rats as well as in rats subjected to endotoxic shock. Changes in mean arterial pressure, pulse pressure, heart rate, and respiratory rate were determined in conscious animals following injection of TRH into the lateral, third, or fourth ventricular spaces. Injections of TRH into the third ventricular space resulted in a greater increase in cardiorespiratory variables than did fourth ventricular injection. In endotoxin-treated rats, the cardiorespiratory effects of intracerebroventricular (icv) TRH and its analog MK 771 were assessed. TRH and MK 771 were shown to act within the brain to reverse endotoxic shock hypotension; at the doses used, the pressor effects of these two tripeptides were achieved through selectively different actions upon heart rate and pulse pressure. Adrenal demedullated and sham-operated control rats subjected to endotoxic shock were injected with icv and intravenous (iv) TRH in order to evaluate the potential involvement of sympatho-medullary function in cardiorespiratory responses. The cardiovascular effects of icv TRH were dependent upon adrenal medullary integrity; effects of iv TRH were not. Doses of iv TRH which effectively reverse shock neither altered nociceptive latencies nor interfered with analgesic responses to morphine. Collectively, these studies reinforce the potential therapeutic utility of TRH and its analogs in the treatment of shock and indicate potential sites and mechanisms which mediate these salutary effects.     

Expression, regulation, and function of B cell-expressed CD154 in germinal centers.

Activated B cells and T cells express CD154/CD40 ligand in vitro. The in vivo expression and function of B cell CD154 remain unclear and therefore were examined. Tonsillar B and T cells expressed CD154 at a similar density both in situ and immediately ex vivo, whereas a significantly higher percentage of the former expressed CD154. CD154-expressing B cells were most frequent in the CD38positiveIgD+ pre-germinal center (GC)/GC founder, CD38positive GC and CD38-IgD- memory populations, and were also found in the CD38-IgD+ naive and CD38brightIgD+ plasmablast subsets, but not in the CD38brightIgD- plasma cell subset. B cell expression of CD154 was induced by engaging surface Ig or CD40 by signals that predominantly involved activation of AP-1/NF-AT and NF-kappaB, respectively. The functional importance of CD154-mediated homotypic B cell interactions in vivo was indicated by the finding that mAb to CD154 inhibited differentiation of CD38positiveIgD- GC B cells to CD38-IgD- memory cells. In addition, mAb to CD154 inhibited proliferation induced by engaging sIg or CD40, indicating the role of up-regulation of this molecule in facilitating B cell responsiveness. Of note, CD154 itself not only functioned as a ligand but also as a direct signaling molecule as anti-CD154-conjugated Sepharose beads costimulated B cell responses induced by engaging surface Ig. These results indicate that CD154 is expressed by human B cells in vivo and plays an important role in mediating B cell responses.     

Changes in the number of neuromediator receptors on murine lymphocytes in ontogeny

It has being shown by radiological methods of evaluation of the binding sites with adrenergic, cholinergic and neuropeptide agents that during mice ontogenesis the number of binding sites to these agents is progressively declined. The cAMP accumulation by lymphoid cells after contact with adrenaline is declined also. The regularities shown may reflect processes of the immune change during the age.     

The morphogenetic patterns of the higher autonomic centers in a pathological pregnancy]

Neurosecretory, parasympathetic and sympathetic centers of 49 mature fetuses subjected to toxicity were studied using light and electron microscopy. These centers were characterized by similar regularities of neurocytes development. Higher degree of maturity was typical for neurosecretory, while minimal for sympathetic centers. A higher degree of maturity and functional performance of vegetative regulatory system predominated in large fetuses. A general rule was a relative independence of forming truncal and spinal morphosystems and their nuclei on body and brain masses. Dyschronia of vegetative centers development reduces an adaptive potential of the fetus and causes fatal outcome in intranatal period.     

Modifying effects of fermented brown rice on fecal microbiota in rats

Brown rice fermented by Aspergillus oryzae (FBRA) is a fiber-rich food. Effects of dietary administration of FBRA on rat fecal microbiota composition were examined. Male Wistar rats were fed a basal diet or a 5% FBRA- or 10% FBRA-containing diet, and fecal microbiota was analyzed by culture and terminal-restriction fragment length polymorphism (T-RFLP) analysis. The viable cell number of lactobacilli significantly increased after feeding 10% FBRA diet for 3 weeks compared with that in the basal diet group and that in the same group at the beginning of the experiment (day 0). An increase in the viable cell number of lactobacilli was also observed after feeding 10% FBRA for 12 weeks compared with the effect of a basal diet. T-RFLP analysis showed an increase in the percentage of lactobacilli cells in feces of rats fed 10% FBRA for 14 weeks. Lactobacilli strains isolated from rat feces were divided into six types based on their randomly amplified polymorphic DNA (RAPD) patterns, and they were identified as Lactobacillus reuteri, L. intestinalis and lactobacilli species based on homology of the partial sequence of 16S rDNA. FBRA contains lactic acid bacteria, but their RAPD patterns and identified species were different from those in rat feces. These results indicated that dietary FBRA increases the number of lactobacilli species already resident in the rat intestine.     

Cannabinoid-hormone interactions in the regulation of motivational processes

There is a bi-directionality in hormone-cannabinoid interactions: cannabinoids affect prominent endocrine axes (such as the hypothalamic-pituitary-gonadal), and gonadal hormones modulate cannabinoid effects. This review will summarize recent research on these interactions, with a specific focus upon their implications for motivated behavior. Sexual behavior will serve as a “case study.” I will explore the hypothesis that ovarian hormones, in particular estradiol, may serve to release estrous behavior from endocannabinoid inhibition. Hormonal regulation of the endogenous cannabinoid system also affects processes that underlie drug abuse. This review will briefly discuss sex differences in behavioral responses to cannabinoids and explore potential mechanisms by which gonadal hormones alter cannabinoid reward. An examination of this research informs our perspective on how hormones and endocannabinoids may affect drug-seeking behavior as a whole and the development of addiction.