Antagonism of analgesics by amine-depleting agents

On the role of a central adrenergic mechanism in morphine analgesic action

“…Reserpine depletes brain catecholainine stores and antagonizes morphine analgesia (Schneider, 1954 ;Radouco-Thomas, Radouco-Thomas & LeBreton, 1957 ;Schaumann, 1958;Paeile & Munoz, 1966;Verri, Graeff & Corrado, 1967;Raevsky, 1969), so, too, does tetrabenazine (Takagi, Takashima & Kimura, 1964). On the other hand, Rudzik & Mennear (1965) believe that the antagonism of morphine by reserpine is not due to its action on catecholamine metabolism. A possible role of 5-hydroxytryptamine (~-H T ) in morphine analgesia has also been considered (MedacoviC & BaniC, 1964;NiCak, 1965).…”

Strong Analgesics

“…Nevertheless, the mode of action of morphine in the brain is largely unknown, although it has attracted much interest (Lim, 1967) and morphine has been shown to alter cerebral metabolism in several ways. It increases the uptake of phosphate by brain tissue (Mule, 1967) and evidence of possible interference with synaptic transmitter substances may be inferred from the decreased breakdown of acetylcholine (Takemori, 1968); the enhancement of the analgesic effectiveness of morphine by neostigmine (Slaughter, 1950) and the antagonistic effect of reserpine (Schneider, 1954), although whether this is related to depletion of catecholamine has been contested (Rudzik and Menear, 1965).…”

Antinociceptive activity of morphine after injection of biogenic amines in the cerebral ventricles of the conscious rat

“…Reserpine, which depletes tissues of both catecholamines and 5-HT, antagonizes the antinociceptive properties of morphine in rats and mice (Schneider, 1954;Schaumann, 1958 ;Sigg et al, 1958 ;Medakovic & Banic, 1964 & Kimura, 1964;Rudzik & Mennear, 1965;Contreras & Tamayo, 1967;Ross & Ashford, 1967;Verri, Graeff & Corrado, 1968). In contrast, there have been reports of a potentiation of the antinociceptive effect of morphine in mice (Tripod & Gross, 1957;Garcia Leme & Rocha e Silva, 1961).…”