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Many Physiological Processes (many + physiological_process)
Selected AbstractsCircadian rhythm disturbances in depression,HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2008Anne Germain Abstract Objective The aim of this article is to review progress in understanding the mechanisms that underlie circadian and sleep rhythms, and their role in the pathogenesis and treatment of depression. Methods Literature was selected principally by Medline searches, and additional reports were identified based on ongoing research activities in the authors' laboratory. Results Many physiological processes show circadian rhythms of activity. Sleep and waking are the most obvious circadian rhythms in mammals. There is considerable evidence that circadian and sleep disturbances are important in the pathophysiology of mood disorders. Depressed patients often show altered circadian rhythms, sleep disturbances, and diurnal mood variation. Chronotherapies, including bright light exposure, sleep deprivation, and social rhythm therapies, may be useful adjuncts in non-seasonal and seasonal depression. Antidepressant drugs have marked effects on circadian processes and sleep. Conclusions Recent progress in understanding chronobiological and sleep regulation mechanisms may provide novel insights and avenues into the development of new pharmacological and behavioral treatment strategies for mood disorders. Copyright © 2008 John Wiley & Sons, Ltd. [source] Influences of the environment on the endocrine and paracrine fish growth hormone,insulin-like growth factor-I systemJOURNAL OF FISH BIOLOGY, Issue 6 2010M. Reinecke Insulin-like growth factor-I (IGF-I) is a key component of the complex system that regulates differentiation, development, growth and reproduction of fishes. The IGF-I gene is mainly expressed in the liver that represents the principal source of endocrine IGF-I but also in numerous other organs where the hormone most probably acts in an autocrine,paracrine manner. The primary stimulus for synthesis and release of IGF-I is growth hormone (GH) from the anterior pituitary. Thus, in analogy to mammals, it is usual to speak of a fish ,GH,IGF-I axis'. The GH,IGF-I system is affected by changes in the environment and probably represents a target of endocrine disrupting compounds (EDC) that impair many physiological processes in fishes. Thus, the review deals with the influences of changes in different environmental factors, such as food availability, temperature, photoperiod, season, salinity and EDCs, on GH gene expression in pituitary, IGF-I gene expression in liver and extrahepatic sites and the physiological effects resulting from the evoked alterations in endocrine and local IGF-I. Environmental influences certainly interact with each other but for convenience of the reader they will be dealt with in separate sections. Current trends in GH,IGF-I research are analysed and future focuses are suggested at the end of the sections. [source] Nitric oxide in plants: the history is just beginningPLANT CELL & ENVIRONMENT, Issue 3 2001M. V. Beligni ABSTRACT Nitric oxide (NO) is a bioactive molecule that exerts a number of diverse activities in phylogenetically distant species, as well as opposing effects in related biological systems. It was firstly described in mammals as a major messenger in the cardiovascular, immune and nervous system, in which it plays regulatory, signalling, cytoprotective and cytotoxic effects (Ignarro, Annual Review of Pharmacology and Toxicology 30, 535,560, 1990; Anbar, Experientia 51, 545,550, 1995). This versatility is mainly achieved through interactions with targets via either a redox or an additive chemistry (Stamler, Cell 78, 931,936, 1994). For this reason, metal- and thiol-containing proteins serve as major target sites for NO: these include signalling proteins, receptors, enzymes, transcription factors and DNA, among others. Furthermore, NO is a small, highly diffusible molecule. It rapidly crosses biological membranes and triggers various different processes in a short period of time. In this context, NO can co-ordinate and regulate cellular functions of microsomes and organelles such as mitochondria. The ubiquity of NO reactions, as well as the finding that the biochemical and molecular mechanisms underlying many physiological processes are well conserved between diverse species, have opened the exploration of NO chemistry in different organisms. Among these, plants were not the exception. The research in plants has been focused on three main fields: (i) the search for NO or any source of NO generation; (ii) the examination of the effects of NO upon exogenous treatments; and (iii) the search for the same molecules involved in NO-sensitive transduction pathways as in animals (e.g. cGMP, Ca2+, calmodulin). As it is evident from this review, recent progress on NO functionality in plants has been impressive. With the use of biochemistry, molecular genetics and structural biology, together with classical physiological approaches, an explosion of new discoveries will surely begin. It is certainly a good time for plant biologists. [source] Proteomics viewed on stress response of thermophilic bacterium Bacillus stearothermophilus,TLS33PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 14 2005Supachai Topanurak Abstract Thermophilic bacterium Bacillus stearothermophilus,TLS33, isolated from a hot spring in Chiang Mai, Thailand, usually produces many enzymes that are very useful for industrial applications. However, the functional properties and mechanisms of this bacterium under stress conditions are rarely reported and still need more understanding on how the bacterium can survive in stress environments. In this study, we examined the oxidative stress induced proteins of this bacterium by proteomic approach combining two-dimensional electrophoresis and mass spectrometry. When the bacterium encountered oxidative stress, peroxiredoxin, as an antioxidant enzyme, is one of the interesting stressed proteins which appeared to be systematically increased with different pI. There are four isoforms of peroxiredoxin, denoted as Prx,I, Prx,II, Prx,III and Prx,IV, which are observed at the same molecular weight of 27,kDa but differ in pI values of 5.0, 4.87, 4.81 and 4.79, respectively. The H2O2 concentration directly increased Prx,II, Prx,III and Prx,IV intensities, but decreased Prx,I intensity. These shifting of peroxiredoxin isoforms may occur by a post-translational modification. Otherwise, the longer time of oxidative stress had not affected the expression level of peroxiredoxin isoforms. Therefore, this finding of peroxiredoxin intends to know the bacterial adaptation under oxidative stress. Otherwise, this protein plays an important role in many physiological processes and able to use in the industrial applications. [source] Selectivity of imidazole,dioxolane compounds for in vitro inhibition of microsomal haem oxygenase isoformsBRITISH JOURNAL OF PHARMACOLOGY, Issue 3 2006Robert T Kinobe Haem oxygenases (HO) are involved in the catalytic breakdown of haem to generate carbon monoxide (CO), iron and biliverdin. It is widely accepted that products of haem catabolism are involved in biological signaling in many physiological processes. Conclusions to most studies in this field have gained support from the judicious use of synthetic metalloporphyrins such as chromium mesoporphyrin (CrMP) to selectively inhibit HO. However, metalloporphyrins have also been found to inhibit other haem-dependent enzymes, such as nitric oxide synthase (NOS), cytochromes P-450 (CYPs) and soluble guanylyl cyclase (sGC), induce the expression of HO-1 or exhibit varied toxic effects. To obviate some of these problems, we have been examining non-porphyrin HO inhibitors and the present study describes imidazole,dioxolane compounds with high selectivity for inhibition of HO-1 (rat spleen microsomes) compared to HO-2 (rat brain microsomes) in vitro. (2R,4R)-2-[2-(4-chlorophenyl)ethyl]-2-[(1H -imidazol-1-yl)methyl]-4-methyl-1,3-dioxolane hydrochloride) was identified as the most selective inhibitor with a concentration of 0.6 ,M inhibiting HO-1(inducible) by 50% compared with 394 ,M for HO-2 (constitutive). These compounds were found to have no effects on the catalytic activities of rat brain NOS and lung sGC, but were potent inhibitors of microsomal CYP2E1 and CYP3A1/3A2 activities. In conclusion, we have identified imidazole,dioxolanes that are able to inhibit microsomal HO in vitro with high selectivity for HO-1 compared to HO-2, and little or no effect on the activities of neuronal NOS and sGC. These molecules could be used to facilitate studies on the elucidation of physiological roles of HO/CO in biological systems. British Journal of Pharmacology (2006) 147, 307,315. doi:10.1038/sj.bjp.0706555 [source] 2222: Hydrogen sulphide: a new CNS mediatorACTA OPHTHALMOLOGICA, Issue 2010N OSBORNE The recent discovery that hydrogen sulphide (H2S) is an endogenously produced gaseous secondary messenger capable of modulating many physiological processes, much like nitric oxide, prompted us to investigate the potential role of H2S as a retinal neuroprotective agent. In the current study we use dithiolethiones (kindly provided by Dr. Piero Del Soldato, Milan, Italy) as H2S donors and show that such substances attenuate the effect of retinal ischemia as well as oxidative and light-induced injury to a transformed line of cells (RGC-5 cells) in culture. Ischemia was delivered to rats by elevation of the intraocular pressure above the systolic blood pressure. Partial damage to the retina after seven days was determined by a combination of procedures which included analysis of electroretinograms, immunohistochemistry and changes in the retinal content of proteins and mRNAs known to be associated with ganglion cell function and apoptosis. Most of the changes caused by ischemia were significantly attenuated by intravitreal injection of a H2S donor directly after ischemia. Both light (400-700nm, intensity 1000 lux) and hydrogen peroxide caused death to RGC-5 cells in culture over a period of 24-48 hours in a time and dose-dependent manner, respectively. Light and hydrogen peroxide-induced RGC-5 cell death is by different forms of apoptosis but they are both attenuated by the H2S donor, ACS1. These initial findings demonstrate that donors of H2S may be value in the treatment of various retinal dysfunctions where oxidative stress, light or ischemia is implicated as causative fact [source] | ||||||||||