N-ethylmaleimide (NEM) diminishes ?2-adrenoceptor mediated effects on noradrenaline release

1986 ◽  
Vol 333 (2) ◽  
pp. 104-109 ◽  
Author(s):  
Clemens Allgaier ◽  
Thomas J. Feuerstein ◽  
Georg Hertting
1985 ◽  
Vol 331 (2-3) ◽  
pp. 235-239 ◽  
Author(s):  
Clemens Allgaier ◽  
Thomas J. Feuerstein ◽  
Rolf Jackisch ◽  
Georg Hertting

1984 ◽  
Vol 51 (01) ◽  
pp. 089-092 ◽  
Author(s):  
M A Boogaerts ◽  
J Van de Broeck ◽  
H Deckmyn ◽  
C Roelant ◽  
J Vermylen ◽  
...  

SummaryThe effect of alfa-tocopherol on the cell-cell interactions at the vessel wall were studied, using an in vitro model of human umbilical vein endothelial cell cultures (HUEC). Immune triggered granulocytes (PMN) will adhere to and damage HUEC and platelets enhance this PMN mediated endothelial injury. When HUEC are cultured in the presence of vitamin E, 51Cr-leakage induced by complement stimulated PMN is significantly decreased and the enhanced cytotoxicity by platelets is completely abolished (p <0.001).The inhibition of PMN induced endothelial injury is directly correlated to a diminished adherence of PMN to vitamin E- cultured HUEC (p <0.001), which may be mediated by an increase of both basal and stimulated endogenous prostacyclin (PGI2) from alfa-tocopherol-treated HUEC (p <0.025). The vitamin E-effect is abolished by incubation of HUEC with the irreversible cyclo-oxygenase inhibitor, acetylsalicylic acid, but the addition of exogenous PGI2 could not reproduce the vitamin E-mediated effects.We conclude that vitamin E exerts a protective effect on immune triggered endothelial damage, partly by increasing the endogenous anti-oxidant potential, partly by modulating intrinsic endothelial prostaglandin production. The failure to reproduce vitamin E-protection by exogenously added PGI2 may suggest additional, not yet elucidated vitamin E-effects on endothelial metabolism.


1982 ◽  
Vol 48 (01) ◽  
pp. 062-066 ◽  
Author(s):  
Chantal Legrand ◽  
Véronique Dubernard ◽  
Philippe Meyer

Summary(3H) noradrenaline was taken up by human platelets and partially converted into sulfoconjugated noradrenaline. This uptake was inhibited by drugs which have been previously shown to impair the uptake of 5-HT (ouabain, chlorimipramine) or the storage of 5-HT (tyramine, reserpine) by platelets. In addition, tyramine and reserpine stimulated the formation of sulfoconjugated noradrenaline. The efflux of noradrenaline from platelets was measured in parallel and was found to be directly related to the proportion of non metabolized to metabolized noradrenaline in the cells. Unlike tyramine, which induced a similar release of noradrenaline and 5-HT, reserpine was less effective at inducing noradrenaline release than 5-HT release. This study indicates a preferential localization of noradrenaline in the granular pool of human platelets with the existence of an extragranular sulfoconjugated pool which is increased when the granular storage of noradrenaline is impaired. Studies of noradrenaline fluxes and metabolism may be useful in the understanding of both acquired and inherited platelet storage pool defects.


2006 ◽  
Vol 114 (S 1) ◽  
Author(s):  
N Perwitz ◽  
B Meier ◽  
M Drenckhan ◽  
M Fasshauer ◽  
J Klein

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