Ganglionic blocking effect of some antibiotics on isolated rat sympathetic ganglion.

It was shown on the isolated superior cervical ganglion of the rat that some antiobiotics exerted a blocking effect nearly as potent as that exhibited by hexamethonium or d-turbocurarine. The ganglionic blockade thus induced proved to be non-specific and due to the local anaesthetic effect of the tested drugs.     

Reduction of exercise inudced hyperventilation by blocking beta adrenergic receptors]

In normal subjects, beta-adrenergic blockage by propranolol or pindolol reduces exercise hyperventilation (40 to 60% VO2 max).     

Influence of adrenergic neuron blocking agents on the adrenaline-induced platelet reactions

Adrenaline causes aggregation of human blood platelets through stimulation of alpha-adrenoceptors resembling the alpha 2-type. Alpha-adrenoceptor blocking agents inhibit specifically the adrenaline-induced platelet reactions. The adrenaline-induced aggregation of human blood platelets was inhibited specifically by adrenergic neuron blocking agents such as guanoxan, guanclofine and guanethidine. Guanoxan (I50 = 0.6 mu mol/l) was about three orders of magnitude more effective than guanethidine, guanclofine occupied a median position. The compounds tested inhibited the ADP- and collagen-induced aggregation at relatively high concentrations. This is probably due to non-specific membrane effects. The known alpha-adrenolytic effect of guanoxan is believed to be mediated mainly by alpha 2-adrenoceptors.