Distribution of the 4-aminopyridine derivative 3-methoxy-4-aminopyridine in mice.

The tissue distribution of [14C]3-Methoxy-4-aminopyridine was studied after intravenous administration in mice using whole body and microautoradiography. Dense accumulation was found in cholinergically innervated, secretory organs. High radioactivity was detected in the adrenal medulla suggesting that the observed excitement and hyperglycemia are due to the stimulation of catecholamine secretion. [14C]3-Methoxy-4-aminopyridine quickly passes the blood brain barrier and predominantly accumulates in the hippocampus, the thalamic nuclei and the cortex.