| Popis: |
x03B4;-opioid 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#x03B4;-opioid agonist DADLE and an endogenous#x03B4;-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 (10sup-8/supM) mildly (average 28#x0025;) decreased the intracellular calcium level after 1 min treatment. The suppressive effect of DADLE (10sup-8/supM) on the intracellular calcium level was enhanced by longer (15 min) treatment of MOLT-4 cells (average 40#x0025;). Met-enkephalin (10sup-9/supM - 10sup-7/supM) decreased (average 33#x0025;) the intracellular calcium level after 2 min treatment (average 33#x0025; - 37#x0025;). However, Met-enkephalin (10sup-7/supM) increased (average 31#x0025;) the intracellular calcium level after longer (15 min) treatment. Ionophore A23187 (10sup-7/supM, 10sup-6/supM) was used as a positive control to enhance intracellular calcium level. Thus,#x03B4;-opioid agonist DADLE decreased 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. |
