The synthetic κ-opioid agonist (-)U50,488 does not affect calcium transport into R1.1 mouse thymoma cell line

Abstract In this paper, the effect of the synthetic κ-opioid agonist (−)U50,488 on 45 Ca 2 transport into R1.1 mouse thymoma cells is presented. This thymoma cell line expresses selectively the κ -opioid class of receptors. 45 Ca 2 transport into R1.1 cells was not affected by the κ -opioid agonist (−)U50,488 (10 −10 M–10 −4 M) alone, or in the presence of the plant lectins: PHA (250 μ g/ml) and Con A (800 μ g/ml), after a 60 min treatment. The plant lectins PHA and Con A stimulated 45 Ca 2 transport into R1.1 cells, in high concentrations (100–800 μ g/ml) and (200–1000 μ g/ml) respectively, after a 60 min treatment. Thus, 45 Ca 2 transport was not affected in R1.1 cells by the κ -opioid agonist (−) U50,488 alone, or in the presence of mitogens after a 60 min treatment. This negative result does not indicate the lack of calcium channels on R1.1 cells, since the plant lectins PHA and Con A were able to stimulate 45 Ca 2 transport into R1.1 cells.