Electromechanical coupling in rat basilar artery in response to morphine. Neurosurgery 1983 Dec;13(6):676-80
Date
12/01/1983Pubmed ID
6657022DOI
10.1227/00006123-198312000-00011Scopus ID
2-s2.0-0021087602 (requires institutional sign-in at Scopus site) 15 CitationsAbstract
Force development, intracellular membrane potential (Em), and voltage vs. current curves were measured in rat basilar artery to help elucidate the mechanism of action of morphine sulfate and a synthetic narcotic, meperidine hydrochloride, on this preparation. Morphine sulfate caused a dose-dependent contraction of these vessels, which was reversible with naloxone. Electrical studies show that morphine may act upon this vascular smooth muscle preparation by decreasing potassium conductance (gk). This hypothesis is supported by the findings that morphine sulfate depolarized these cells and increased the input resistance (rin) determined by the application of rectangular hyperpolarizing and depolarizing current pulses through the microelectrode during impalement and recording of the associated voltage changes (delta V). Meperidine hydrochloride had significantly less effect on this preparation than morphine sulfate. Further studies show that the vehicular medium used for the commercially available preparation of naloxone (viz. the methyl and propyl esters of p-hydroxybenzoic acid in a ratio of 9:1) is, in vitro, a vasodilator of cerebral vascular smooth muscle.
Author List
Waters A, Harder DRMESH terms used to index this publication - Major topics in bold
AnimalsBasilar Artery
Cerebrovascular Circulation
Dose-Response Relationship, Drug
Electric Conductivity
Male
Membrane Potentials
Meperidine
Morphine
Muscle Contraction
Muscle, Smooth, Vascular
Naloxone
Parabens
Pharmaceutical Vehicles
Potassium
Rats
Rats, Inbred Strains
