Extracts of the cephamycin C producer S. lactamdurans were found to possess cystathionine gamma-lyase activity (E.C. 4.4.1.1). This represents the first demonstration of this enzyme of the reverse transsulfuration pathway in a prokaryotic organism. A likely involvement of reverse transsulfuration in antibiotic synthesis is indicated by the fact that propargylglycine, a mechanism-based inhibitor...

High homocysteine (HCy) levels are associated with lymphocyte-mediated inflammatory responses that are sometimes in turn related to hypoxia. Because adenosine is a potent lymphocyte suppressor produced in hypoxic conditions and shares metabolic pathways with HCy, we addressed the influence of high HCy levels on the hypoxia-induced, adenosine-mediated, alteration of lymphocyte viability. We trea...

Antigen-activated T lymphocytes undergo an immune or tolerogeneic response in part according to the activation status of their antigen-presenting cells. However, factors controlling the activation of antigen-presenting cells are not fully understood. In this study, we demonstrate that immune tolerance after organ allotransplantation in the rat is associated with a repressed intragraft expressio...

BACKGROUND Diabetic nephropathy (DN) is one of the complex complications of Diabetes Mellitus (DM). The present study has been designed to examine protective role of hydrogen Sulphide (H2S) donor against streptozotocin (STZ) -induced behavioral, oxidative abnormalities and its DN like symptoms in rats. METHODS For the induction of DN single intraperitoneal administration of STZ (45 mg/kg) was...

BACKGROUND H(2)S synthesis inhibitors (HSSI) have been shown to impact respiratory control. For instance, the HSSI hydroxylamine (HA) decreases the respiratory discharge rate from isolated medullary sections, and HA in addition to other HSSIs propargylglycine and amino-oxyacetic acid (AOAA) have been found to reduce hypoxic responsiveness. OBJECTIVES The aim of this study was to determine if ...

The contribution of cystathionine gamma-lyase, cystathionine beta-synthase and cysteine aminotransferase coupled to 3-mercaptopyruvate sulphurtransferase to cysteine desulphhydration in rat liver and kidney was assessed with four different assay systems. Cystathionine gamma-lyase and cystathionine beta-synthase were active when homogenates were incubated with 280 mM-L-cysteine and 3 mM-pyridoxa...

The present study aimed to investigate the role of hydrogen sulphide (H2S) in the cardioprotection induced by ischemic postconditioning and to examine the underlying mechanisms. Cardiodynamics and myocardial infarction were measured in isolated rat hearts. Postconditioning with six episodes of 10-s ischemia (IPostC) significantly improved cardiodynamic function, which was attenuated by the bloc...

The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and 90 mg·kg(-1), p.o.), and after 30 min, they were administered 50% ethanol (0.5 mL/25 g(-1), p.o.). One hour...