Release of thromboxane B2 and leukotriene C4 and reduction in renal perfusion in experimental anaphylactic reaction of isolated guinea pig kidney

Cysteinyl leukotrienes synthesis is involved in aristolochic acid I-induced apoptosis in renal proximal tubular epithelial cells

Aristolochic acid I (AAI) is a primary nephrotoxin and carcinogen that is found in some Chinese herbal medicines, and AAI is responsible for the progression of aristolochic acid nephropathy. The membrane associated proteins in the eicosanoid and glutathione metabolism (MAPEG) superfamily are associated with cysteinyl leukotrienes (cysLTs) synthesis. The present study investigated whether cysLTs synthesis was involved in AAI-induced renal proximal tubular epithelial cell injury in LLC-PK1 cells. Based on MAPEG and related molecular events, the potential mechanisms of AAI-induced LLC-PK1 cell injury were explored. AAI triggered the mitochondrial/caspase apoptotic pathway in LLC-PK1 cells, which was indicated by an enhanced Bax/Bcl-2 ratio, loss of mitochondrial membrane potential, cytochrome C release, and caspase 3 activation. In addition, AAI-induced cysLTs release was accompanied by selective upregulation of 5-lipoxygenase activating protein (FLAP) and microsomal glutathione S-transferase 3 (mGST3) in a concentration-dependent manner. The FLAP inhibitor MK866 significantly protected cells from AAI-induced apoptosis. Furthermore, activation of extracellular signal-regulated kinase (ERK) 1/2 and inhibition of phosphorylated p38-MAPK were demonstrated at the early phase of AAI treatment. Notably, the MEK/ERK inhibitor U0126 reversed AAI-induced apoptosis and reduced both FLAP, mGST3 and mitochondrial/caspase protein expression. Taken together, these findings suggest that cysLTs synthesis is involved in AAI-induced apoptosis via an ERK activation way.

Immune release of histamine and other lipid mediators from guinea-pig isolated kidney: antagonism by BN-52021

The ability of a specific PAF-receptor antagonist, BN-52021, to control the release of mediators of anaphylaxis from actively sensitized (ovalbumin) guinea-pig has been investigated "in vitro". BN-52021 perfused through the kidney at different molar concentrations (1 x 10(-4)-1 x 10(-5)-1 x 10(-6] prior to antigen challenge neither modified the basal values of perfusion pressure nor stimulated mediator release from the organ. On the contrary, the compound antagonized in a concentration dependent way both vasoconstriction of the renal vessels and the increase in the perfusate of histamine, TXB2 and SRS-A due to antigenic shock. The antagonistic activity of BN-52021 was very consistent at 1 x 10(-4) M at which concentration the immunological release of histamine and TXB2 was reduced by 75%. The beneficial effect of BN-52021 in experimental anaphylaxis of the kidney may have some therapeutic implications principally in those pathological conditions where an abnormal increase of renal histamine and other mediators may compromise the haemodynamic function of this organ.

Role of thromboxane A2, leukotriene C4 and histamine in the antigen-induced vasoconstriction in perfused, sensitized guinea-pig kidney

The existence of a role for TXA2, histamine, and possibly LTC4 in the antigen-induced renal vasoconstriction in isolated, perfused kidney of sensitized guinea-pigs is demonstrated.

Substance P and Arg-Pro-Lys-Pro-NH-C12-H25-induced mediator release from different mast cell subtypes of rat and guinea-pig

Histamine was released from mast cells in isolated perfused heart and kidney of the rat, but not from mast cells in guinea-pig tissues, by a substance P (SP) analogue (SP(1-4)-NH-C12H25), SP(1-4)-C12 for abbreviation. This peptide also released histamine from peritoneal mast cells and basophil leucocytes of the rat. Substance P itself was compared with SP(1-4)-C12 and some structurally related peptides and showed weaker activity. SP(1-4)-C12 also released leukotrienes C4, D4, E4 and thromboxane B2 from rat heart. However, there was little effect on heart rate and force of contraction and no effect on perfusion pressure (vascular resistance) of either rat heart or kidney. The findings demonstrate the structural requirements for histamine release by SP (a possible mediator of 'neurogenic' inflammation), the metabolic energy-dependence of the release process and the functional heterogeneity and interspecies differences in mast cell populations.

Cardiac and renal mast cells: morphology, distribution, fixation and staining properties in the guinea pig and preliminary comparison with human

In guinea pig (GP) and human heart and kidney cell or tissue preparations fixed with Carnoy's fluid (but not with formol-saline), mast cells (MC) were extremely well preserved and could be detected after staining with alcian blue (AB). Although histamine content and distribution in GP and human heart appeared to be different, morphological and histochemical studies of MC suggested a similarity between the two species and a clear distinction from rat peritoneal MC.

Mast cells and IgE-mediated release of histamine and arachidonate metabolites from human kidney

We report a pilot study of mast cells and IgE-mediated release of histamine, leukotrienes and thromboxanes from human kidney. The results together with previous findings in the guinea-pig and rat suggest that mast cells and IgE may play an important role in kidney disease.

Anaphylatoxin-induced release of histamine from in vitro perfused guinea pig kidney

The effect of porcine C5a des Arg and C3a, given as a bolus injection, in the isolated constant flow pump-perfused guinea-pig kidney was investigated. Only C5a des Arg showed activity which was manifested by a dose-dependent increase in perfusion pressure (PP, due to vasoconstriction) and histamine release. Although histamine release was substantial, it alone could not account for the increase in PP. The two more likely causes are a direct vasoconstrictor effect and the release of other mediators.