An investigation of the role of adrenergic innervation in the regulation of the extraneuronal uptake of [3H]‐isoprenaline into rat vasa deferentia and atria

Destruction of adrenergic nerves by neonatal guanethidine treatment did not affect the extraneuronal accumulation of [3H]-isoprenaline by adult vasa deferentia or atria. Neither pre- nor post-ganglionic denervation of vasa deferentia resulted in a significant change in extraneuronal accumulation of [3H]-isoprenaline. The appearance and subsequent development of extraneuronal uptake in embryonic and newborn rats did not appear to be dependent on a fully developed or functional adrenergic innervation. Decreasing plasma catecholamine levels by adrenal demedullation did not have an effect on extraneuronal uptake. Chronic cold exposure (7 days) significantly increased plasma levels of adrenaline, and there was a significant decrease in the corticosterone-sensitive extraneuronal uptake of [3H]-isoprenaline into atria. After 14 days in the cold, plasma adrenaline levels had fallen, and were no longer significantly different from control levels. The extraneuronal uptake of [3H]-isoprenaline into atria after 14 days cold exposure was no longer different from that of control atria. There did not appear to be a direct correlation between plasma catecholamines and extraneuronal accumulation of [3H]-isoprenaline. Neither the presence of adrenergic nerves nor plasma catecholamines appear to play a major role in the regulation of extraneuronal uptake by atria and vasa deferentia of the rat.