[Inhibition of histamine liberation in allergic rhinoconjunctivitis in relation to the season].
An increased activity of the cAMP-degrading enzyme phosphodiesterase (PDE) has been observed in peripheral leukocytes from atopic patients. We studied 9 patients with seasonal allergic rhinoconjunctivitis and 9 controls during (summer) and out of symptomatic season (following winter). Dextran sedimented peripheral mixed leucocytes (pML) were preincubated with the nonspecific PDE inhibitor isobutyl-methylxanthine (IBMX), with the PDE III selective inhibitor motapizone and with the PDE IV selective inhibitor rolipram and subsequently histamine release was induced by anti-IgE antibodies. The anti-IgE induced histamine release (anti-IgE HR) showed no significant seasonal differences in atopic patients and in controls. All PDE inhibitors reduced anti-IgE HR over the whole investigated concentration range (from 10(-8) mol/l to 10(-4) mol/l) in a dose dependent manner. Comparing the PDE inhibitors rolipram was the most potent inhibitor on anti-IgE HR from pML of acute and symptomless patients, while there were no significant differences on anti-IgE HR from pML of controls. During symptomatic season rolipram inhibited anti-IgE HR from pML of patients significantly more efficient than out of season. This could be the result of a seasonal increased PDE IV activity in the pMI of patients with allergic rhinoconjunctivitis.
Räderer
I
I
Walther-Straub-Institut für Pharmakologie und Toxikologie, Universität München, Deutschland.
Haen
E
E
Schudt
C
C
Przybilla
B
B
D000328:Adult; D001683:Biological Clocks / Q000502:physiology*; D003233:Conjunctivitis, Allergic / Q000276:immunology*; D005260:Female; D006636:Histamine Release / Q000502:physiology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000502:physiology; D012016:Reference Values; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D012621:Seasons
D007073:Immunoglobulin E; D010727:Phosphoric Diester Hydrolases