PT - JOURNAL ARTICLE AU - PETER M. ROBINSON AU - JOHN R. McLEAN AU - GEOFFREY BURNSTOCK TI - ULTRASTRUCTURAL IDENTIFICATION OF NON-ADRENERGIC INHIBITORY NERVE FIBERS DP - 1971 Nov 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 149--160 VI - 179 IP - 2 4099 - http://jpet.aspetjournals.org/content/179/2/149.short 4100 - http://jpet.aspetjournals.org/content/179/2/149.full SO - J Pharmacol Exp Ther1971 Nov 01; 179 AB - The fine structure of intra-axonal vesicles in autonomic nerves supplying the lung of the toad Bufo marinus has been examined. About 50% of axon profiles contain many large granular vesicles (600-2000 Å in diameter) together with some small, oblate profiles with electron-transparent cores. These large granular vesicles have a different form from the large granular vesicles found in small numbers in adrenergic nerces. Most of the remaining axon profiles contain exclusively small agranular vesicles. Degeneration of adrenergic nerve fibers in the toad after long-term application of 6-hydroxydopamine fails to alter either the profiles containing large granular vesicles or the inhibitory response to stimulation of non-adrenergic nerves. Short-term application of 6-hydroxydopamine (used as a marker to identify catecholamine-containing vesicles) does not alter the large granular vesicles in the lung although it forms dense cores in vesicles in adrenergic nerves in the heart. After depletion of the catecholamine content of the lung with reserpine or metaraminol (as determined by fluorescent histochemistry and spectrofluorimetric assay) the number and density of large granular vesicles remains unchanged. It is concluded that axon profiles containing predominantly large granular vesicles in the toad lung represent non-adrenergic, non-eholinergic inhibitory nerves. © 1971 by The Williams & Wilkins Co.