Acció facilitadora dels fàrmacs adrenèrgics sobre la neurotransmissió en el múscul esquelètic de rata

The effect of alphaadrenegic drugs on the skeletal muscle junction manifests itself as an increased functional response in various experimental situations. The sbtype of receptor implicated has not been fully ascertained. In order to clrify this point, we used the in vitro pharmacological sample of a phreno-diaphragmatic preparation in which the facilitating effect on contractility produced by alpha-adregenic drugs was studied, as well as its inhibition by both specific and nonspecific antagonists. The present study shows evidence demonstrating the implication of an alpha-1 type receptor possibly different from those described in other structures. We also suggest that the mechanisms involved in this facilitation by adrenergic drugs, in basal conditions and in the presence of tubocurarine, can be different