Sphingosine Increases ATP Release From Red Blood Cells

Background: RBC plays a pivotal role in oxygen delivery, improving distribution where it needs. When RBC enters a low oxygen area, a mechanism mediated by a signaling pathway releases ATP, responsible for vasodilatation. Objective: Clarify the potential role of sphingosine on the release of ATP from RBC. Methods: ATP release increases after sphingosine exposure in RBC under low oxygen conditions. ATP release in deoxygenated RBC shows data like that of control RBC: (1) RBC after band 3 modification by 4,4'- diisothio-cyanato-stilbene- 2,2'-disulphonic acid (DIDS); (2) CO-treated RBC. Unlike phosphofructokinase, adenylate cyclase (AC) activity increases after exposure to sphingosine. Results: We show that cAMP synthesis and ATP release are not failed in sphingosine-treated red blood cells in response to incubation with mastoparan 7, forskolin plus 3-isobutyl-1-methyl xanthine, agents that stimulate cAMP synthesis. Conclusion: Deoxy-hemoglobin, band 3, and AC are involved in the signaling pathway responsible for ATP released after sphingosine exposure.