[The effect of BL 343 Ac, a beta-adrenolytic, on the cervical ganglion]

The activity of the newly synthetized substance BL 343 Ac (propyl-3-acetyl-4[/2-hydroxy-3-isopropyl amino/propoxy] carbanylate of hydrochloride), a beta 1-adrenolytic with sympathomimetic activity was investigated by means of the electrophysiological method of sucrose gap. Its effect on the membrane potential of a population of neurons of the superior cervical ganglion (GCS) of the cat was analyzed with the aim to contribute to the knowledge on the selectivity of action of this substance. In the GCS of the cat, which contains predominantly beta 2-adrenoceptors, BL 343 Ac given in concentrations from 0.01 to 50 mumol.l-1 and after single application into the superfusion stream close to the ganglion in doses from 0.01 to 1,000 nmol did not induce an unequivocal change in the membrane potential or a response comparable to that elicited by isoprenaline. No blocking effect of the substance BL 343 Ac (0.01-50 mumol.l-1) was observed on isoprenaline induced depolarization of the cat GCS. The obtained results indicate that BL 343 Ac fails to exert either beta 2-adrenomimetic or beta 2-adrenolytic effect on the GCS of the cat. (Fig. 2, Ref. 11.)