PT  - JOURNAL ARTICLE
AU  - C Berends
AU  - B Dijkhuizen
AU  - JG de Monchy
AU  - AE Dubois
AU  - J Gerritsen
AU  - HF Kauffman
TI  - Inhibition of PAF-induced expression of CD11b and shedding of L-selectin on human neutrophils and eosinophils by the type IV selective PDE inhibitor, rolipram
AID  - 10.1183/09031936.97.10051000
DP  - 1997 May 01
TA  - European Respiratory Journal
PG  - 1000--1007
VI  - 10
IP  - 5
4099  - http://erj.ersjournals.com/content/10/5/1000.short
4100  - http://erj.ersjournals.com/content/10/5/1000.full
SO  - Eur Respir J1997 May 01; 10
AB  - We quantitatively determined whether the selective phosphodiesterase (PDE) inhibitor, rolipram, inhibits changes in the adhesion molecules CD11b and L-selectin on platelet-activating factor (PAF)-stimulated human neutrophils and eosinophils in vitro. Incubations were performed in human whole blood obtained from healthy volunteers, to restrict activation by purification procedures and to simulate in vivo conditions, in which different cell types may interact, more closely. Receptor expression was measured after fixation of cells, using monoclonal antibodies and flow cytometry. Concentration-dependent inhibition of the PAF-induced CD11b expression and L-selectin shedding for neutrophils and eosinophils was observed with rolipram, dibutyryl cyclic adenosine monophosphate (cAMP), prostaglandin E2 (PGE2), and isoproterenol. However, these inhibitions did not exceed 50%. Preincubation with rolipram (10(-8) M) and subsequent incubation with isoproterenol (0.5x10(-8) M) or PGE2 (10(-8) M) induced a cumulative, but not synergistic, effect. Using the combination of rolipram with isoproterenol or PGE2, inhibition of PAF-induced L-selectin shedding from eosinophils was as high as 71+/-28 and 67+/-21%, respectively. Other inhibitions were below 50%. In conclusion, rolipram inhibits CD11b expression and L-selectin shedding of platelet-activating factor-stimulated neutrophils and eosinophils in whole blood in a concentration-dependent fashion. Inhibitions did not exceed 50%, even at high concentrations. The inhibition of platelet-activating factor induced shedding of L-selectin from eosinophils with a combination of rolipram and prostaglandin E2 or isoproterenol, however, was found to be approximately 70%. Inhibition of rolling adhesion of eosinophils may, therefore, be a mode of action of type IV phosphodiesterase inhibitors.