title: The effects of vertebral artery injections of an enkephalin analogue, (D-Met2,Pro5)-enkephalinamide, on somatosympathetic reflexes.
abstract: The present study was initiated to test the effects of intravertebral arterial injection of an enkephalin analogue (D-Met2,Pro5)-enkephalinamide on somatosympathetic responses to myelinated A afferent and to unmyelinated C afferent stimulation (A- and C-reflex, respectively). In anesthetized cats, 0.5 mg/kg administered directly into the vertebral artery, the artery supplying most of the cat brain stem and upper cervical spinal cord, depressed both the A- and C-reflex (to 66 and 64% of control, respectively) while intravenous or carotid arterial injections did not have any effect on these reflexes. It is suggested that intravertebral arterial administration may be a useful method of restricting the effective sites of delivery of biologically active compounds to areas of the brain supplied by this artery.
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001812:Blood-Brain Barrier; D002415:Cats; D002490:Central Nervous System / Q000187:drug effects*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D007269:Injections, Intra-Arterial; D009020:Morphine / Q000494:pharmacology; D009412:Nerve Fibers / Q000187:drug effects; D009413:Nerve Fibers, Myelinated / Q000187:drug effects; D012018:Reflex / Q000187:drug effects*; D014711:Vertebral Artery
chemical_list: D000700:Analgesics; D004744:Enkephalin, Methionine; C021717:enkephalin, Met(2)-ProNH2(5)-; D009020:Morphine