Osmolytes are a class of compounds ubiquitously used by living organisms to respond to cellular stress or to fine-tune molecular properties in the cell. These compounds are also highly useful in vitro. In this chapter, we give an overview of the possible uses of osmolytes in the laboratory, and how we can investigate and understand their modes of action. Experimental procedures are discussed wi...

Salinity adversely affects plant growth and development, and disturbs intracellular ion homeostasis, resulting in cellular toxicity. Plants that tolerate salinity, halophytes, do so by manifesting numerous physiological and biochemical processes in coordination to alleviate cellular ionic imbalance. The present study was undertaken to analyse the salt tolerance mechanism in Aeluropus lagopoides...

BACKGROUND Halophilic bacteria have shown their significance in industrial production of polyhydroxyalkanoates (PHA) and are gaining more attention for genetic engineering modification. Yet, little information on the genomics and PHA related genes from halophilic bacteria have been disclosed so far. RESULTS The draft genome of moderately halophilic bacterium, Halomonas sp. TD01, a strain of g...

Experiments on Gulf toadfish Opsanus beta demonstrate how feeding impacts osmoregulation in the marine teleost intestine. A high Ca(2+) diet of pilchards Sardina pilchardus ([Ca(2+)]=404.2 mmol kg(-1)) was compared to a low Ca(2+) diet of common squid Loligo forbesi ([Ca(2+)]=1.3 mmol kg(-1)), as high [Ca(2+)] has been shown to stimulate intestinal anion exchange. Gastrointestinal fluids and bl...

BACKGROUND & AIMS The pathogenesis of brain edema in patients with chronic liver disease (CLD) and minimal hepatic encephalopathy (HE) remains undefined. This study evaluated the role of brain lactate, glutamine and organic osmolytes, including myo-inositol and taurine, in the development of brain edema in a rat model of cirrhosis. METHODS Six-week bile-duct ligated (BDL) rats were injected w...

We compared levels of the major organic osmolytes in the muscle of elasmobranchs, including the methylamines trimethylamine oxide (TMAO), betaine and sarcosine as well as the beta-amino acids taurine and beta-alanine, and the activities of enzymes of methylamine synthesis (betaine and TMAO) in species with a wide range of urea contents. Four marine, a euryhaline in freshwater (Dasyatis sabina),...