Inhibition of platelet aggregation by a whole cell extract from strains of group B streptococcus.
A whole cell extract (HCl-Ext) from strains of group B streptococci (GBS) possessing fibrinogen binding activity prevented the platelet aggregation induced with adenosine 5'-diphosphate (ADP), collagen and thrombin, while aggregation by epinephrine and ristocetin was slightly inhibited and arachidonic acid-induced platelet aggregation was not affected whatsoever. When the HCl-Ext was added after commencement of the aggregation, deaggregation was observed in cases induced by ADP, collagen, and thrombin. By precoating the washed platelets with HCl-Ext, both of ADP- and collagen-induced platelet aggregation were suppressed. The active factor in the HCl-Ext seemed to be undialyzable, trypsin-susceptible, and proteinaceous substance, unlike GBS polysaccharide type antigen.
St. Marianna University School of Medicine, Kawasaki, Japan.
Y
Y
Usui
Y
Y
Ichiman
T
T
Ohtomo
M
M
Suganuma
K
K
Yoshida
D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D006851:Hydrochloric Acid; D010975:Platelet Aggregation Inhibitors; D011485:Protein Binding; D013292:Streptococcus agalactiae / Q000502:physiology*
D010975:Platelet Aggregation Inhibitors; D005340:Fibrinogen; D006851:Hydrochloric Acid