The effect of sodium cromoglycate on platelets: an in vivo and in vitro approach.
Platelet functions are altered in patients suffering from atopic diseases, including asthma. Such alterations might be related to IgE since platelets bear a specific IgE receptor termed Fc epsilon receptor II, and there is some evidence that IgE alone, that is, in the absence of antigen, could modify platelet functions, such as monoamine uptake. Although disodium cromoglycate (DSCG) has been demonstrated to interfere with IgE-mediated activation of human platelets, its effect in the absence of antigen remains unknown. We examined the DSCG effect on IgE-induced alterations both in vivo and in vitro. The effect, in vivo, of a daily intake of 40 mg of DSCG for 4 weeks was assessed on platelet kinetics, studied by a labeling technique on four patients with stable asthma. The effect, in vitro, of DSCG was assessed on IgE-induced alteration in monoamine uptake in platelets from 12 healthy subjects. DSCG significantly increased, in vivo, the mean time constant of platelet-survival curves from 234 +/- 40 to 463 +/- 150 hours (p less than 0.01). The amplitude of this effect increased with the patient's serum IgE concentration. DSCG, in vitro, reduced the inhibitory effect of IgE on monoamine uptake by 82%. This effect was concentration dependent and not related to IgE binding. It is concluded that DSCG alters both the survival time of platelets from allergic patients in vivo and the IgE-dependent monoamine uptake in platelets from normal subjects in vitro. These effects are likely to be related to the direct action of DSCG on cells bearing the Fc epsilon receptor II and might be independent of the specific trigger.
Tunon-de-Lara
J M
JM
Service des Maladies Respiratoires, Hôpital du Haut-Lévêque, Pessac, France.
Rio
P
P
Marthan
R
R
Vuillemin
L
L
Ducassou
D
D
Taytard
A
A
D000328:Adult; D001249:Asthma / Q000097:blood*; D001679:Biogenic Amines / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D004205:Cromolyn Sodium / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood*; D007700:Kinetics; D008297:Male; D012016:Reference Values
D001679:Biogenic Amines; D004205:Cromolyn Sodium