On the mechanism of action of an adrenergic blocking guanidine (CG8345-Go).

CG 8345 depletes noradrenaline stores in the rat, cat and dog tissues at a dose range of 1--50 mg/kg p.o. Unlike guanethidine there is no marked difference in the depleting effect of CG 8345 when given orally or intraperitoneally. The effect on the noradrenaline stores is longer lasting in cats and dogs as compared to rat. Like guanethidine CG 8345 releases H3-NA from the rat heart mainly in the form of bases. The compound gets accumulated into the sympathetically innervated organs by a specific uptake process which is similar to noradrenaline "pump" mechanism from where it can be released by reserpine. CG 8345 is stored in the same storage sites as noradrenaline in the rat heart.