α‐Adrenoceptor stimulated lymphocytes trigger the mechanical response of vas deferens: participation of arachidonic acid metabolites
Normal human lymphocytes (L) (8 × 105 ml−1) incubated with methoxamine (Me) (1 × 10−7 M) (Me‐L) triggered the mchanical response of the isolated vas deferens of the rat. L or Me alone did not modify this contractile activity at the concentrations cited above. Me alone (10−6 to 10−3 M) increased the...
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1984
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00071188_v82_n4_p863_Borda http://hdl.handle.net/20.500.12110/paper_00071188_v82_n4_p863_Borda |
| Aporte de: |
| Sumario: | Normal human lymphocytes (L) (8 × 105 ml−1) incubated with methoxamine (Me) (1 × 10−7 M) (Me‐L) triggered the mchanical response of the isolated vas deferens of the rat. L or Me alone did not modify this contractile activity at the concentrations cited above. Me alone (10−6 to 10−3 M) increased the tension of the vas. In the presence of L (8 × 105 ml−1) the dose‐response curve to Me shifted to the left and the efficacy of Me was enhanced. Inhibitors of α1‐adrenoceptors completely blocked the reaction between Me and L while drugs that block α1 and α2‐adrenoceptors reduced the reaction between Me‐L and the vas deferens. Direct contact of Me‐L with the assay organ was not necessary. Cell‐free supernatants of L exposed to Me (Me‐L supernatants) elicited the reaction in the same way as Me‐L. This effect required the continuous presence of Me since dialyzed Me‐L supernatants were inactive. Inhibitors of lipoxygenase(s) completely blocked the positive inotropic effect of Me‐L or of Me‐L supernatants. Inhibitors of cyclo‐oxygenase potentiated this effect. These results suggest that Me reacts with α1‐adrenoceptors of L. From this reaction, soluble factors are released that potentiate the α‐adrenoceptor stimulatory effect of Me on the vas deferens as a consequence of the release of oxidative products of the lipoxygenase/s pathway of arachidonic acid. 1984 British Pharmacological Society |
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