engleski

The effect of delta-opioid agonists on intracellular calcium level in MOLT-4 cell line

Delta-opoioid agonists were reported to affect T cell functions: proliferation, cytotoxicity, cytokine production. Changes in intracellular calcium level are important in T-cell activation. In this study the effect of the synthetic delta-opioid agonist DADLE and an endogenous delta-opioid pentapeptide Met-enkephalin on the intracellular calcium level in human T-lymphoblastic leukemia MOLT-4 cells is reported. Intracellular calcium level was monitored using QUIN 2-AM as a fluorescent dye in MOLT-4 cells after short treatment (2 and 15 min) with DADLE and Met-enkephalin. DADLE (10-8M) mildly (average 28%) decreased the intracellular calcium level after 1 min treatment. The suppressive effect of DADLE (10-8M) on the intracellular calcium level was enhanced by longer treatment (15 min) of MOLT-4 cells (average 40%), Met-enkephalin (10-9M - 10-7M) decreased (average 33%) the intracellular calcium level after 2 min treatment (average 33%-37%). However, Met-enkephalin (10-7M) increased (average 31%) the intracellular calcium level after longer (15 min) treatment. Ionophore A23187 (10-7M, 10-6M) was used as a positive control to enhance intracellular calcium level. Thus. delta-opioid agonist DADLE decresed basal intracellular calcium level in MOLT-4 cells after short treatment, while endogenous Met-enkephalin altered intracellular calcium level in a bidirectional way by decreasing and increasing it.

intracellular calcium; delta-opioids; MOLT-4 cells

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