Potentiation of platelet responses in vitro by feline infectious peritonitis virus.
The effect of feline infectious peritonitis virus (FIPV) on platelet aggregation and 14C-serotonin release induced by threshold levels of four agonists (adenosine diphosphate [ADP], collagen, arachidonic acid, and epinephrine) was examined in vitro in ten specific-pathogen-free cats. Purified suspensions of FIPV added to stirred platelet suspensions (virus to platelet ratio equal to 1:320) 1 minute prior to the addition of agonist potentiated the ADP-induced aggregation response by greater than 100% in seven cats. Platelet 14C-serotonin release was increased by greater than 100% in four cats. Collagen-induced platelet aggregation was enhanced in ten cats while collagen-induced 14C-serotonin release was enhanced in eight cats. Potentiation of arachidonic acid-induced platelet aggregation was observed in three cats, two of which demonstrated enhanced platelet 14C-serotonin release. Although epinephrine-induced platelet aggregation was enhanced in five cats, the samples displayed only fine microaggregates. Enhanced 14C-serotonin release from platelets in response to epinephrine was not demonstrated. Interaction with the outer platelet membrane and internalization of viral particles within the surface-connected open canalicular system were demonstrated by electron microscopy within 5 minutes of the addition of virus to platelet suspensions with or without added agonists. Decreasing the virus concentration by ten- or one hundred-fold abolished the potentiating effect observed previously, while increasing the concentration tenfold resulted in direct platelet activation in the absence of agonist.(ABSTRACT TRUNCATED AT 250 WORDS)
Boudreaux
M K
MK
Auburn University, College of Veterinary Medicine, Department of Pathobiology, AL.
Weiss
R C
RC
Toivio-Kinnucan
M
M
Spano
J S
JS
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000382:microbiology* / Q000648:ultrastructure; D002415:Cats; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D003332:Coronaviridae / Q000502:physiology* / Q000648:ultrastructure; D004837:Epinephrine / Q000494:pharmacology; D008854:Microscopy, Electron; D010974:Platelet Aggregation / Q000187:drug effects; D012701:Serotonin / Q000097:blood; D013047:Specific Pathogen-Free Organisms
D001095:Arachidonic Acids; D012701:Serotonin; D000244:Adenosine Diphosphate; D003094:Collagen; D004837:Epinephrine