Morphine antagonises action of prostaglandin in neuroblastoma and neuroblastoma × glioma hybrid cells

Effects of cholinergic agents and sodium ions on the levels of guanosine and adenosine 3′:5′‐cyclic monophosphates in neuroblastoma and neuroblastoma x glioma hybrid cells

“…The first, the elevation of the level of cyclic GMP in the hybrid cells, had been expected, since cholinergic agonists attenuate the increase of the level of cyclic AMP caused by prostaglandin El [7] or adenosine [21]. Such action of prostaglandin El is also obviated by noradrenaline [5] and morphine [8,19], 2 agents known to increase the intraceUular levels of cyclic GMP [11,20] in the hybrids. Cholinergic agonists increase the level of cyclic GMP in heart [22,23], brain [23][24][25], liver and thyroid [26], ileum [25], vas deferens [27], fat cells [28] and lung [29] and partially prevent the increase of the concentration of cyclic AMP by isoproterenol or glucagon in heart [30] or by adrenaline in uterus [31].…”

“…In the hybrid and neuroblastoma ceils the intracellular level of cyclic AMP strongly increases in response to prostaglandin El [6]. This action of prostaglandin E1 is potently obviated by noradrenaline [5], acetylcholine [7] and opiates [8][9][10]. The effect of opiates is probably mediated by cyclic GMP [11 ].…”

“…The osmolality of the latter was adjusted to 320 mosM by the addition of choline chloride. The cholinergic agents were added as described [8]. After the extraction, separation and purification, cyclic GMP [11 ] and cyclic AMP [8] were determined by protein binding assays.…”

Endorphins exert opiate‐like action on neuroblastoma X glioma hybrid cells

“…Four days later the medium was removed, the cells were washed once with 5 ml of incubation medium (37°C) and, unless stated otherwise, were incubated (37°C 10 min) with 5 ml of this medium containing PGEr (0.3 PM) and the peptides. Thereafter, the intracellular concentration of cyclic AMP was determined [29].…”

“…HCl and PGEr were gifts from Hoffman-LaRoche, Grenzach, Germany, and Dr J. Pike, Upjohn Co., Kalamazoo, Michigan, respectively. 2.4 X 10' viable (exclusion of nigrosin) neuroblastoma X glioma hybrid cells 108CC 15 were seeded onto plastic dishes (85 mm in diameter, containing 20 ml of growth medium) and cultured as described [29] . Four days later the medium was removed, the cells were washed once with 5 ml of incubation medium (37°C) and, unless stated otherwise, were incubated (37°C 10 min) with 5 ml of this medium containing PGEr (0.3 PM) and the peptides.…”