Molecular mechanisms involved in the inhibitory action of dehidroleucodine on mast cell degranulation

FERRARIS P; LEIVA N; BARRERA P; MOLINA M; ROGGERO M; MARIANI ML; PENISSI AB

Universidad Nacional de Cuyo. Mendoza. Argentina.

Congreso; XX Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2002

Sociedad de Biología de Cuyo

In previous works we have shown that dehydroleucodine (DhL) is able to inhibit mast cells (MC) degranulation induced by various chemical agents. In this analysis, we compared the effect of DhL on different degranulation activators in order to trace its molecular mechanism of action. Peritoneal rat MC were isolated and incubated for 20 min at 37ºC with: 1) buffer; 2) DhL (1.6 mM); 3) 48/80 (Gi protein activator; 10 mg/ml); 4) DhL+48/80; 5) A23187 (calcium ionophore; 10 mg/ml); 6) DhL+A23187; 7) Ethanol (PLC and PLD activator; 10%); 8) DhL+Ethanol. Released and remnant serotonin (5-HT) was quantified by HPLC. Compound 48/80, A23187 and ethanol increased 5-HT secretion compared to controls. DhL totally inhibited 5-HT secretion induced by 48/80 and by ethanol, and partially that induced by A23187. MC from 48/80, A23187 and ethanol groups showed evident morphological alterations and decreased granular density. DhL inhibited those alterations. Inhibition in MC degranulation appears to be related to adenilatocyclase activation, or to phospholipase C and/or D inhibition.