title: Effects of morphine on superior cervical ganglion and iris of the immature rat.
abstract: Morphine injections in 16-day-old rats caused an increase in norepinephrine concentration in both superior cervical ganglion and iris after 1 h. Although the increase in the ganglion was blocked by naloxone pretreatment, the increase in the iris was not prevented. The morphine-induced increase did not require the presence of intact central connections. These findings demonstrate that morphine has direct effects on peripheral catecholaminergic systems in immature rats.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D002395:Catecholamines / Q000032:analysis; D002490:Central Nervous System / Q000502:physiology; D005728:Ganglia, Sympathetic / Q000032:analysis / Q000187:drug effects*; D007498:Iris / Q000187:drug effects* / Q000378:metabolism; D009020:Morphine / Q000494:pharmacology*; D009638:Norepinephrine / Q000032:analysis / Q000378:metabolism; D051381:Rats / Q000502:physiology*
chemical_list: D002395:Catecholamines; D009020:Morphine; D009638:Norepinephrine