Salt stress, its impacts on plants and the strategies plants are employing against it: A review

Salt stress is said as the most harmful environmental issue affecting the agricultural productivity of manycrops, with deleterious effect on plant growth, physiological and biochemical characteristics, vigour, and cropyields. Salt stress induced oxidative stress in plants by generating reactive oxygen species (ROS) that resultsimpairment of cellular membranes, proteins of cells and organelles, especially of mitochondria, chloroplast,and peroxisomes and affects overall integrity of the cell. The various types of ROS are 1O2, H2O2, O2•−, andOH•. Salinity creates osmotic stress in plants that diminishes the root water absorption capacity and causes lossof water from the leaves that increases the accumulation of salts in salt stressed plants. However, plants showtolerance toward salt stress by involving large number of adaptations, for example, osmotic adjustment, ionhomeostasis, hormonal regulation, antioxidant defense system, etc. Biosynthesis of plant growth hormones,such as cytokinins, abscisic acid, auxin, jasmonic acid, gibberellin, and ethylene play important role inamelioration of salt stress in plants by altering biochemical and physiological process plant tissues. Plantsdevelop ion homeostasis in order to eliminate additional salt ions from cytosol by primary and secondarytransport, maintains the balance of cytosolic concentration of Na+ and K+ ions, thus keeps the low concentrationof Na+ ions in cytosol as they are very harmful to cell when present in higher level. Plants develop antioxidantsystem constituting enzymatic components catalase, glutathione peroxidase, superoxide dismutase, ascorbateperoxidase, monodehydroascorbate reductase, and glutathione reductase and non-enzymatic components, suchas glutathione, cysteine, tocopherols, and ascorbate that eliminate or neutralize ROS to cope with the oxidativestress by the antioxidant defense system and protect themselves against detrimental effects of ROS. In thisreview, we discuss on salt stress lead production of ROS, their formation, effects, and scavenging.

Fetal development of regulatory mechanisms for body fluid homeostasis

The balance of body fluids is critical to health and the development of diseases. Although quite a few review papers have shown that several mechanisms, including hormonal and behavioral regulation, play an important role in body fluid homeostasis in adults, there is limited information on the development of regulatory mechanisms for fetal body fluid balance. Hormonal, renal, and behavioral control of body fluids function to some extent in utero. Hormonal mechanisms including the renin-angiotensin system, aldosterone, and vasopressin are involved in modifying fetal renal excretion, reabsorption of sodium and water, and regulation of vascular volume. In utero behavioral changes, such as fetal swallowing, have been suggested to be early functional development in response to dipsogens. Since diseases, such as hypertension, can be traced to fetal origin, it is important to understand the development of fetal regulatory mechanisms for body fluid homeostasis in this early stage of life. This review focuses on fetal hormonal, behavioral, and renal development related to regulation of body fluids in utero.

Ejercicio y sistema inmune / Exercise and the immune system

Se ha demostrado que el ejercicio hecho a diferentes intensidades cumple una función moduladora sobre diversos sistemas, y que su acción sobre la respuesta inmune es de gran importancia. Por lo tanto, es necesario esclarecer si estos cambios constituyen efectos benéficos o perjudiciales en cuanto a las adaptaciones del hospedero frente a diversos agentes patógenos. El estudio de estos cambios inducidos por el estrés físico puede tener un impacto grande en la comprensión y prevención de algunas enfermedades que involucran la respuesta del sistema inmune como las alergias, las infecciones, las inmunodeficiencias y el cáncer. En este artículo se presenta una revisión actualizada de la información existente al respecto, con el propósito de aportar elementos que ayuden a comprender este fenómeno biológico, así como sus implicaciones para la salud humana. Se han estudiado varios parámetros de la respuesta inmune durante el ejercicio físico, entre ellos su relación con la respuesta hormonal al estrés y el comportamiento de las diferentes hormonas de acuerdo con la intensidad de aquél. También se han evaluado los cambios en las poblaciones de células sanguíneas (linfocitos, monocitos y neutrófilos) así como el comportamiento de las citoquinas y la síntesis de inmunoglobulinas específicas. Todo esto ha permitido establecer una relación entre los sistemas inmune y neuroendocrino, la cual explicaría en gran medida los diferentes cambios que ocurren durante la actividad física en la respuesta y la adaptación inmunes, así como las diferencias de acuerdo con la intensidad y la frecuencia del estrés físico

It has been demonstrated that physical exercise, carried out at diverse intensities, modulates the function of different human body systems, and that it plays a major role in the immune response. Therefore, it is necessary to find out if these changes have benefic or harmful effects on the host adaptation against several pathogenic agents. The study of these physical-stress-induced changes might have a great impact on the comprehension and prevention of some diseases that involve activation of the immune system such as allergies, infections, immunodeficiencies and cancer. This article presents a review of current information concerning this area, with the purpose of providing concepts to help readers understand this biological phenomena and their implications in human health. Several immune response parameters have been studied during physical exercise, including their relationship with the stress-induced hormonal response and the profile of different hormones according to the intensity of physical activity. Also, changes in blood cell populations (lymphocytes, monocytes and neutrophils) and the behavior of cytokines and the synthesis of specific immune globulins have been assessed. This knowledge has allowed to establish a relationship between the immune and neuroendocrine systems, which might explain the various changes in the immune response and the adaptation seen in physical activity, as well as the differences found at diverse exercise intensity and frequency levels

ALCOHOL DRINKING AND HEALTH / 体力科学

The present article briefly overviews the principal pathway of ethanol metabolism in the liver cell and hormonal regulations of ethanol metabolism, and a relationship between alcohol drinking volume (=alcohol consumption) and the degree of alcohol intoxication. This article also focuses on a possible mechanism of sex difference in rat liver cytosolic alcohol dehydrogenase (ADH) activity, and the effects of bile, bile acids, vegetable oils and unsaturated fatty acids on plasma ethanol levels and gastric emptying in ethanol-administered rats. Finally, the recent findings concernig a relationship between alcohol drinking and human health are described.