ISSN:
1432-1912
Schlagwort(e):
Cyclooxygenase inhibitors
;
Lithium
;
Alpha1-adrenoceptors
;
Inotropic action
;
Guinea-pig atrium
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary In experiments on the isolated guinea-pig left atrium we tried to get more information about the intracellular signal transmission of the alpha1-adrenoceptor. We were able to demonstrate that the cyclooxygenase inhibitors indometacin and acetylsalicylic acid enhance the positive inotropic effect of relatively low phenylephrine concentrations at an extracellular calcium concentration of 1.22 mmol/l. Preincubation with prazosin as well as an increased calcium concentration of 2.5 mmol/l abolished this effect. These observations led us to suppose that an elevated level of receptor-generated arachidonic acid, whose degradation is inhibited by the cyclooxygenasen inhibitors, caused the increased contractility by releasing more calcium from the sarcoplasmic reticulum. Under these conditions also lithium caused a distinct enhancement of the positive inotropic effect evoked by alpha, -adrenergic agonists, probably by inhibiting the degradation of the second messenger inositol trisphosphate.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00164873
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